1. Introduction: Enzymes Overview

Here’s an experiment you should try at home.

Take any starchy food (a cracker, a piece of white bread, a spoonful of rice, or a spoonful of mashed potatoes). Place it in your mouth and chew for a long time—an uncomfortably long time. Close your eyes, and focus on your taste buds. After a while, the starchy taste will be accompanied by the taste of sugar. Where did that sugar come from?

08_starch, amylase, maltoseStarch is a polymer of glucose. In your saliva, you have an enzyme called amylase. When you eat any food with starch, amylase breaks the starch into maltose, a disaccharide. In other words, as you chew and mix the food with saliva, an enzyme in your saliva is breaking starch into sugar (which is why you can sense the sweetness).

Enzymes are the substances that control the chemical reactions that occur in all living things – bacterial cells, daffodils, lizards, and, people. It’s hard to overstate their importance.

2. Interactive Reading: Enzymes and Activation Energy

[qwiz style=”width: 550px !important; min-height: 400px !important;”]

[h] Enzymes and Activation Energy

[i] Why do you need to strike a match to get it to burst into flames? It’s all about activation energy. In living things, enzymes lower the activation energy required to start life’s chemical reactions. Click start to see how.

[q multiple_choice=”true”] Let’s start by defining a few key terms. Catalysts are substances that speed up chemical reactions, without themselves being changed or used up by the reaction. Enzymes are the catalysts in living things. Almost all enzymes are proteins. Because enzymes are catalysts, however much enzyme is present at the start of a reaction is how much there will be at the end.

To make sure you’re getting this, answer this question: A student is experimenting with amylase, the enzyme used to break down starch. She adds 2 grams of the enzyme to a test tube. At the end of the experiment, how much enzyme should be left in the test tube?

[c]IDAgZ3JhbXM=[Qq]

[f]IE5vLiBCZWNhdXNlIGVuenltZXMgYXJlIGNhdGFseXN0cywgdGhleSYjODIxNztyZSBub3QgdXNlZCB1cCBpbiB0aGUgY2hlbWljYWwgcmVhY3Rpb25zIHRoYXQgdGhleSYjODIxNztyZSBzcGVlZGluZyB1cC4gWW91JiM4MjE3O2xsIGhhdmUgYXMgbXVjaCBlbnp5bWUgYXQgdGhlIGVuZCBvZiB0aGUgcmVhY3Rpb24gYXMgeW91IGhhZCBhdCB0aGUgc3RhcnQu[Qq]

[c]IDEgZ3JhbQ==[Qq]

[f]IE5vLiBCZWNhdXNlIGVuenltZXMgYXJlIGNhdGFseXN0cywgdGhleSYjODIxNztyZSBub3QgdXNlZCB1cCBpbiB0aGUgY2hlbWljYWwgcmVhY3Rpb25zIHRoYXQgdGhleSYjODIxNztyZSBzcGVlZGluZyB1cC4gWW91JiM4MjE3O2xsIGhhdmUgYXMgbXVjaCBlbnp5bWUgYXQgdGhlIGVuZCBvZiB0aGUgcmVhY3Rpb24gYXMgeW91IGhhZCBhdCB0aGUgc3RhcnQu[Qq]

[c]IDIgZ3 JhbXM=[Qq]

[f]IFllcy4gQmVjYXVzZSBlbnp5bWVzIGFyZSBjYXRhbHlzdHMsIHRoZXkmIzgyMTc7cmUgbm90IHVzZWQgdXAgaW4gdGhlIGNoZW1pY2FsIHJlYWN0aW9ucyB0aGF0IHRoZXkmIzgyMTc7cmUgc3BlZWRpbmcgdXAuIFlvdSYjODIxNztsbCBoYXZlIGFzIG11Y2ggZW56eW1lIGF0IHRoZSBlbmQgb2YgdGhlIHJlYWN0aW9uIGFzIHlvdSBoYWQgYXQgdGhlIHN0YXJ0OiBpbiB0aGlzIGNhc2UsIDIgZ3JhbXMu[Qq]

[q multiple_choice=”true”] Enzymes belong to which biomolecule family?

[c]IGNhcmJvaHlkcmF0ZXM=[Qq]

[f]IE5vLiBFbnp5bWVzIGFyZSBub3QgY2FyYm9oeWRyYXRlcy4gSGVyZSYjODIxNztzIGEgaGludC4gVGhlIG1vbm9tZXJzIG9mIHRoZSBtYWNyb21vbGVjdWxlIHRoYXQgZW56eW1lcyBhcmUgbWFkZSB1cCBvZiBhcmUgYW1pbm8gYWNpZHMu[Qq]

[c]IHByb3 RlaW5z[Qq]

[f]IFllcy4gQWxtb3N0IGFsbCBlbnp5bWVzIGFyZSBwcm90ZWlucy4=[Qq]

[c]IGxpcGlkcw==[Qq]

[f]IE5vLiBFbnp5bWVzIGFyZSBub3QgbGlwaWRzLiBIZXJlJiM4MjE3O3MgYSBoaW50LiBUaGUgbW9ub21lcnMgb2YgdGhlIG1hY3JvbW9sZWN1bGUgdGhhdCBlbnp5bWVzIGFyZSBtYWRlIHVwIG9mIGFyZSBhbWlubyBhY2lkcy4=[Qq]

[q multiple_choice=”true”] Enzymes

[c]IHNsb3cgZG93biBjaGVtaWNhbCByZWFjdGlvbnM=[Qq]

[f]IE5vLiBFbnp5bWVzIGRvbiYjODIxNzt0IHNsb3cgZG93biByZWFjdGlvbnMu[Qq]

[c]IHNwZWVkIHVwIGNoZW1p Y2FsIHJlYWN0aW9ucw==[Qq]

[f]IFllcy4gRW56eW1lcyBzcGVlZCB1cCBjaGVtaWNhbCByZWFjdGlvbnM=[Qq]

[c]IGRvIG5vdCBhZmZlY3QgdGhlIHJhdGUgb2YgY2hlbWljYWwgcmVhY3Rpb25z[Qq]

[f]IE5vLiBFbnp5bWVzIGRvIGltcGFjdCB0aGUgcmF0ZSBvZiBjaGVtaWNhbCByZWFjdGlvbnMuIFRoaW5rIGFib3V0IHdoYXQgY2F0YWx5c3RzIGRvLCBhbmQgeW91JiM4MjE3O2xsIGhhdmUgeW91ciBhbnN3ZXIu[Qq]

[q labels = “right”]Enzymes work by lowering the activation energy of a reaction. To understand this, think about what happens in a reaction that releases energy, such as burning a match. Think of the reactant (the chemicals in the match that go into the chemical reaction) as a rock high on a hill. Similarly, think of the product (the chemical or chemicals that come out of a chemical reaction) as that same rock, lower down on the same hill. The rock’s energy can only be released if you give the rock a push. When you light a match, that push is striking the match. The name for the push needed to start a reaction is activation energy. Knowing that, label this diagram.

 

[l]Activation energy

[f*] Great!

[fx] No, that’s not correct. Please try again.

[l]Energy of the product

[f*] Excellent!

[fx] No. Please try again.

[l]Energy of the reactant

[f*] Good!

[fx] No, that’s not correct. Please try again.

[q] Compare the two images below. The image on the left is the one that you just labeled. The one on the right shows the effect of an enzyme.

Reaction without an enzyme Reaction with an enzyme

The type of energy that is changed by the enzyme is the [hangman] [hangman].

[c]IEFjdGl2YXRpb24=[Qq]

[f]IEdyZWF0IQ==[Qq]

[c]IGVuZXJneQ==[Qq]

[f]IEdyZWF0IQ==[Qq]

[q multiple_choice=”true”] Compare the two images below.

A burning match The energy released in reactions

Which letter represents the energy released by the burning match? Note that there’s no letter “D” in this diagram.

[c]IEEgwqAgwqAg[Qq][c]IEIgwqDCoCDCoCA=[Qq][c]IEMgwqAgwqAg[Qq][c]IE U=[Qq][f]IE5vLiBBIHJlcHJlc2VudHMgdGhlIGNoZW1pY2FsIGVuZXJneSBpbiB0aGUgbWF0Y2ggKHRoZSBlbmVyZ3kgb2YgdGhlIHJlYWN0YW50cyk=

Cg==[Qq]

[f]IE5vLiBCIHJlcHJlc2VudHMgdGhlIGNoZW1pY2FsIGVuZXJneSBpbiB0aGUgcHJvZHVjdHMgb2YgdGhlIHJlYWN0aW9uIChjYXJib24gZGlveGlkZSwgd2F0ZXIsIGxlZnRvdmVyIGFzaCku[Qq]

[f]IE5vLiBDIHJlcHJlc2VudHMgdGhlIGFjdGl2YXRpb24gZW5lcmd5[Qq]

[f]IFllcy4gRSByZXByZXNlbnRzIHRoZSBlbmVyZ3kgKGhlYXQgYW5kIGxpZ2h0KSByZWxlYXNlZCBieSB0aGUgbWF0Y2ggYXMgaXQgYnVybnMuIEl0JiM4MjE3O3MgdGhlIGRpZmZlcmVuY2UgYmV0d2VlbiB0aGUgZW5lcmd5IG9mIHRoZSByZWFjdGFudHMgYW5kIHRoZSBlbmVyZ3kgb2YgdGhlIHByb2R1Y3RzLg==[Qq]

[q multiple_choice=”true”] Compare the two images below.

A burning match The energy released in reactions

Which letter represents the energy involved in striking the match (note that there’s no letter “D” in this diagram)?

[c]IEEgwqAgwqAg[Qq][c]IEIgwqDCoCDCoCA=[Qq][c]IEMgwq AgwqAg[Qq][c]IEU=[Qq][f]IE5vLiBBIHJlcHJlc2VudHMgdGhlIGNoZW1pY2FsIGVuZXJneSBpbiB0aGUgbWF0Y2ggKHRoZSBlbmVyZ3kgb2YgdGhlIHJlYWN0YW50cyk=

Cg==[Qq]

[f]IE5vLiBCIHJlcHJlc2VudHMgdGhlIGNoZW1pY2FsIGVuZXJneSBpbiB0aGUgcHJvZHVjdHMgb2YgdGhlIHJlYWN0aW9uIChjYXJib24gZGlveGlkZSwgd2F0ZXIsIGxlZnRvdmVyIGFzaCku[Qq]

[f]IFllcy4gQ8KgcmVwcmVzZW50cyB0aGUgZW5lcmd5IGluIHN0cmlraW5nIHRoZSBtYXRjaCwgb3IgYWN0aXZhdGlvbiBlbmVyZ3k=[Qq]

[f]IE5vLiBFIHJlcHJlc2VudHMgdGhlIGVuZXJneSAoaGVhdCBhbmQgbGlnaHQpIHJlbGVhc2VkIGJ5IHRoZSBtYXRjaCBhcyBpdCBidXJucy4gSXQmIzgyMTc7cyB0aGUgZGlmZmVyZW5jZSBiZXR3ZWVuIHRoZSBlbmVyZ3kgb2YgdGhlIHJlYWN0YW50cyBhbmQgdGhlIGVuZXJneSBvZiB0aGUgcHJvZHVjdHMu[Qq]

[q labels = “top”]Let’s re-emphasize this key point: Enzymes lower the _____________ energy required to bring about the chemical reactions that sustain life. That might not sound important, but it is. Think of how much heat is released when a car burns ___________. That level of heat is typical of the activation energy required to make chemical reactions happen in non-living systems (like a car). In living organisms, the ________________ are always much lower than in most mechanical systems. The only reason why reactions in living things happen is that ___________ are moving those reactions along. Your body has thousands of enzymes, at work every second, controlling the ___________ that keep you going.

[l]activation

[f*] Good!

[fx] No. Please try again.

[l]enzymes

[f*] Great!

[fx] No. Please try again.

[l]gasoline

[f*] Excellent!

[fx] No. Please try again.

[l]reactions

[f*] Correct!

[fx] No. Please try again.

[l]temperatures

[f*] Correct!

[fx] No. Please try again.

[q labels = “top”]If you can label this diagram, then you understand the relationship between activation energy and enzymes.

 

[l]activation energy with an enzyme

[f*] Good!

[fx] No. Please try again.

[l]activation energy without an enzyme

[f*] Excellent!

[fx] No. Please try again.

[l]overall energy released by the reaction

[f*] Good!

[fx] No, that’s not correct. Please try again.

[l]entire reaction with an enzyme

[f*] Good!

[fx] No. Please try again.

[l]entire reaction without an enzyme

[f*] Correct!

[fx] No, that’s not correct. Please try again.

[l]product

[f*] Correct!

[fx] No, that’s not correct. Please try again.

[l]reactant

[f*] Correct!

[fx] No. Please try again.

[x][restart]

[/qwiz]

3. Interactive Reading: Enzymes and Substrates

[qwiz style=”width: 550px !important; min-height: 400px !important;”]

[h]Interactive Reading: Enzymes and Substrates

[i]Now that we understand enzymes and activation energy, let’s see how enzymes work.

[q]The thing that an enzyme acts upon is called a substrate. As a general rule, each enzyme interacts with only one substrate. For example, amylase, the enzyme discussed in the introduction to this tutorial, can break down the polysaccharide starch into the disaccharide maltose.

True or false: Because amylase can break down starch, it can probably break down proteins, too.

[c]VHJ1ZQ==[Qq]

[c]RmFs c2U=[Qq]

[f]Tm8uIEVuenltZXMgZ2VuZXJhbGx5IGhhdmUgb25seSBvbmUgc3Vic3RyYXRlLiBUaGUgc3Vic3RyYXRlIG9mIGFteWxhc2UgaXMgc3RhcmNoLCBhbmQgbm90aGluZyBlbHNlLg==[Qq]

[f]Q29ycmVjdC4gVGhlIHN0YXRlbWVudCBpcyBmYWxzZS7CoEVuenltZXMgZ2VuZXJhbGx5IGhhdmUgb25seSBvbmUgc3Vic3RyYXRlLiBUaGUgc3Vic3RyYXRlIG9mIGFteWxhc2UgaXMgc3RhcmNoLCBhbmQgbm90aGluZyBlbHNlLg==[Qq]

[q labels = “top”]

In the image on the left, you can see a representation of the interaction between an enzyme and its substrate. In reality, most enzymes are MUCH bigger than their substrates. The enzyme (1) binds with the substrate (3) at a specific region of the enzyme called the active site (2). The fit between an enzyme’s active site and the enzyme’s substrate is as specific as the fit between a lock and a ______In the same way as a lock will respond to only ______ key, the _________ can only act upon substrates that fit into its _________ site.

[l]active

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]enzyme

[fx] No. Please try again.

[f*] Correct!

[l]key

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]one

[fx] No. Please try again.

[f*] Great!

[q labels = “top”]The best word for the match between enzyme and substrate is complementary. Things that are complementary match each other. They go together. In Mexican cuisine, rice is complementary to _______. In Italian cuisine, spaghetti is complementary to _____________. An important clue to the history of the Earth and the drifting of the continents is the complementary fit between Africa’s west coast and __________________‘s east coast. One reason why Mr. W often wears black jeans with a black shirt is that he’s bad at choosing __________________ colors.

[l]beans

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]complementary

[fx] No. Please try again.

[f*] Correct!

[l]meatballs

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]South America

[fx] No. Please try again.

[f*] Correct!

[q]

When enzymes bind with a substrate, they form a temporary unit called an enzyme-substrate complex. In a reaction where the enzyme breaks a substrate apart (like the one shown here), the enzyme will place stress on the bonds holding the substrate together and snap those bonds apart. This changes the substrate into a product. In the diagram above, the enzyme-substrate complex must be at

[textentry single_char=”true”]

[c]NA ==[Qq]

[f]TmljZSBqb2IuIFRoZSBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXggaXMgYXQgNC4=[Qq]

[c]Kg==[Qq]

[f]Tm8uIEZpbmQgdGhlIGFyZWEgb24gdGhlIGRpYWdyYW0gd2hlcmUgdGhlIGVuenltZSBhbmQgdGhlIHN1YnN0cmF0ZSBhcmUgdGVtcG9yYXJpbHkgY29ubmVjdGVkIGFzIGEgc2luZ2xlIHVuaXQu[Qq]

[q]

In the diagram above, the product must be at

[textentry single_char=”true”]

[c]NQ ==[Qq]

[f]TmljZSBqb2IuIFRoZSBwcm9kdWN0wqBpcyBzaG93biBhdCA1Lg==[Qq]

[c]Kg==[Qq]

[f]Tm8uwqBJbiB0aGlzIHJlYWN0aW9uLCB0aGUgZW56eW1lIGhhcyBicm9rZW4gdGhlIHN1YnN0cmF0ZSBpbnRvIHR3byBwaWVjZXMuIFdoZXJlIGRvIHlvdSBzZWUgdHdvIHBpZWNlcz8=[Qq]

[q]Here’s a question for review. In terms of their biomolecule family, enzymes are [hangman] catalysts.

[c]cHJvdG Vpbg==[Qq]

[f]TmljZSBqb2IuIEVuenltZXMgYXJlIHByb3RlaW4gY2F0YWx5c3RzLg==[Qq]

[q]Another review question. In terms of shape, the active site of an enzyme is [hangman] to the shape of the enzyme’s substrate.

[c]Y29tcGxlbW VudGFyeQ==[Qq]

[f]TmljZSBqb2IuIEluIHRlcm1zIG9mIHNoYXBlLCB0aGUgYWN0aXZlIHNpdGUgb2YgYW4gZW56eW1lIGlzIA==Y29tcGxlbWVudGFyeQ==wqB0byB0aGUgc2hhcGUgb2YgdGhlIGVuenltZSYjODIxNztzwqBzdWJzdHJhdGUu[Qq]

[q]

In the diagram above, the substrate must be at

[textentry single_char=”true”]

[c]Mw ==[Qq]

[f]TmljZSBqb2IuIFRoZSBzdWJzdHJhdGXCoGlzIHNob3duIGF0IDMu[Qq]

[c]Kg==[Qq]

[f]Tm8uwqBUaGUgc3Vic3RyYXRlIGlzIHdoYXQmIzgyMTc7cyBnb2luZyB0byBiZSBhY3RlZCB1cG9uIGJ5IHRoZSBlbnp5bWUuIElmIHRoZSBlbnp5bWUgaXMgYXQgMSwgd2hpY2ggbnVtYmVyIG11c3QgaW5kaWNhdGUgdGhlIHN1YnN0cmF0ZT8=[Qq]

[q]

An extension of the lock and key idea is the notion of induced fit. When an enzyme binds with a substrate it changes its shape. This change in shape is part of the way that an enzyme stresses the bonds of its substrate as it converts the substrate into a product. In the diagram above, which number indicates where the active site has first changed its shape through induced fit?

[textentry single_char=”true”]

[c]Mw ==[Qq]

[f]TmljZSBqb2IuIE51bWJlciAzIGlzIHBvaW50aW5nIHRvIHdoZXJlIHRoZSBlbnp5bWUmIzgyMTc7cyBhY3RpdmUgc2l0ZSBoYXMgY2hhbmdlZCBzaGFwZSB0byBjb25mb3JtIHdpdGggaXRzIHN1YnN0cmF0ZS4=[Qq]

[c]Kg==[Qq]

[f]Tm8uIExvb2sgYXQgdGhlIGFjdGl2ZSBzaXRlIGF0IG51bWJlciAxLiBUaGlzIGlzIHRoZSBhY3RpdmUgc2l0ZSYjODIxNztzIG9yaWdpbmFsIHNoYXBlLsKgV2hlcmUgZG9lcyB0aGF0IHNoYXBlIGNoYW5nZT8=[Qq]

[q]The process by which an enzyme changes its shape to better match the shape of its substrate is called [hangman] [hangman].

[c]aW5kdWNlZA==[Qq]

[c]Zml0[Qq]

[q]

In the diagram above, which letter indicates the moment when the enzyme is releasing its product?

[textentry single_char=”true”]

[c]RA ==[Qq]

[f]TmljZSBqb2IuIExldHRlciAmIzgyMjA7RCYjODIyMTsgaW5kaWNhdGVzIHRoZSBtb21lbnQgd2hlbiB0aGUgZW56eW1lIGlzIHJlbGVhc2luZyBpdHMgcHJvZHVjdA==[Qq]

[c]Kg==[Qq]

[f]Tm8uIFN0dWR5IHRoZSBkaWFncmFtIGJlbG93LiBZb3UgY2FuIHNlZSB0aGF0IGluIHRoZSBsYXN0IGltYWdlLCB0aGUgZW56eW1lIGlzIHJlbGVhc2luZyBpdHMgcHJvZHVjdC4=

Cg==
SW5kdWNlZCBmaXQsIGZyb20gV2lraXBlZGlh
[Qq]

 

[q labels = “top”]

 

[l]active site

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]enzyme

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]enzyme-substrate complex

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]product

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]substrate

[fx] No. Please try again.

[f*] Excellent!

[q labels = “top”]

 

[l]product

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]substrate

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]enzyme-substrate complex

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]enzyme

[fx] No. Please try again.

[f*] Excellent!

[l]active site

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]active site modified by induced fit

[fx] No. Please try again.

[f*] Good!

[l]enzyme still bound to product

[fx] No, that’s not correct. Please try again.

[f*] Good!

[x]

[restart]

[/qwiz]

4. Interactive Reading: Enzymes and their environment

[qwiz style=”width: 550px !important; min-height: 400px !important;”]

[h]Interactive Reading: Enzymes and their environment

[i]At this point, you should understand:

  1. How enzymes reduce activation energy
  2. How enzymes interact with their substrates to catalyze reactions

Now, let’s turn to how enzymes are affected by the conditions in their environment.

[q]Enzymes are found in a variety of places in living systems. Some enzymes operate inside cells. Others are found inside organs, such as the stomach or the intestines. Some organisms, like fungi, secrete enzymes outside their bodies. In every case, enzymes are affected by the environment in which they work.

Here’s a very straightforward example of how an enzyme is affected by its environment. An enzyme is placed in solutions with pH 1, pH 2, and pH 3.  As shown in the graph below, which pH (level of acidity) shows the highest level of enzyme activity?

[c]IDEgwqAgwqA=[Qq][c]MiDCoC DCoA==[Qq][c]Mw==

Cg==[Qq]

[f]Tm8uIEF0IHBIIDEsIHRoZSBlbnp5bWUmIzgyMTc7cyBhY3Rpdml0eSAoc2hvd24gb24gdGhlIFktYXhpcykgaXMgdmVyeSBsb3cuIFdoaWNoIHBIIG51bWJlciBzaG93cyB0aGUgaGlnaGVzdCBsZXZlbCBvZiBhY3Rpdml0eT8=[Qq]

[f]Q29ycmVjdC4gQXQgcEggMiwgdGhlIGVuenltZSBpcyBhdCBpdHMgbWF4aW11bSBsZXZlbCBvZiBhY3Rpdml0eS4=[Qq]

[f]Tm8uIEF0IHBIIDMsIHRoZSBlbnp5bWUmIzgyMTc7cyBhY3Rpdml0eSAoc2hvd24gb24gdGhlIFktYXhpcykgaXMgdmVyeSBsb3cuIFdoaWNoIHBIIHNob3dzIGEgaGlnaGVyIGxldmVsIG9mIGFjdGl2aXR5Pw==[Qq]

[q labels = “top”]Why would an enzyme’s activity vary so dramatically in relationship to pH (or other aspects of its environment)? Enzymes only work if their shape complements their ___________‘s shape. This fit occurs at one special place on the enzyme:  at the _______ site. Because enzymes are __________, their shape is based on many interactions between the ________ acids that make them up. If you change an enzyme’s ______________, especially by changing the temperature or the pH, you’ll change those amino acid interactions. This changes the enzyme’s _______, which will decrease or block its ability to ______ with its substrate.

[l]active

[fx] No. Please try again.

[f*] Correct!

[l]amino

[fx] No. Please try again.

[f*] Good!

[l]bind

[fx] No. Please try again.

[f*] Good!

[l]environment

[fx] No. Please try again.

[f*] Good!

[l]proteins

[fx] No. Please try again.

[f*] Good!

[l]shape

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]substrate

[fx] No, that’s not correct. Please try again.

[f*] Great!

[q]

When a change in an enzyme’s environment changes the enzyme’s shape in a way that reduces its ability to catalyze reactions, the enzyme is said to be denatured. The process is called denaturation.

In the diagram at left. Assume that 1 is the substrate. Which number is the denatured enzyme?

[textentry single_char=”true”]

[c]Mw ==[Qq]

[f]RXhjZWxsZW50LiBZb3UgY2FuIHNlZSB0aGF0IGF0IDMsIHRoZSBzaGFwZSBvZiB0aGUgZW56eW1lIG5vIGxvbmdlciBmaXRzIHdpdGggaXRzIHN1YnN0cmF0ZS4=[Qq]

[c]Kg==[Qq]

[f]Tm8uIExvb2sgZm9yIHRoZSByZXByZXNlbnRhdGlvbiBvZiBhbsKgZW56eW1lIHdob3NlIHNoYXBlIGhhcyBjaGFuZ2VkIHNvIHRoYXQgaXQgbm8gbG9uZ2VyIGNvbXBsZW1lbnRzIGl0cyBzdWJzdHJhdGUu[Qq]

[q]Denaturation can be reversible or irreversible. If the enzyme can return to its previous state, then the denaturation is reversible. If the denaturation is permanent, then the denaturation is irreversible.

While egg white is not an enzyme, it is a protein. When you cook an egg, you take the liquid protein, and, through cooking, you denature it, making it into a solid. That egg while will never return to its previous form. That’s irreversible denaturation.

[q]

Let’s look again at this graph showing how changing pH (how acidic or basic a solution is) can change enzyme activity and cause denaturation. Which of the following statements is true?

[c]QXMgcEggcmlzZXMsIHNvIGRvZXMgdGhlIGxldmVsIG9mIGVuenltZSBhY3Rpdml0eS4=[Qq]

[c]QXMgcEggcmlzZXMgZnJvbSAyIHRvIDMsIGVuenltZSBhY3Rpdml0eSBpbmNyZWFzZXMu[Qq]

[c]QXMgcEggcmlzZXMgZnJvbSAyIHRvIDMsIG VuenltZSBhY3Rpdml0eSBkZWNyZWFzZXMu[Qq]

[f]Tm8uIEZvciB0aGlzIGVuenltZSwgYXMgcEggcmlzZXMsIGVuenltZSBhY3Rpdml0eSByaXNlcyB1bnRpbCBhIGNlcnRhaW4gcG9pbnQgKHBIIDIpLCBhZnRlciB3aGljaCBpdCBmYWxscy4=[Qq]

[f]Tm8uIEZvciB0aGlzIGVuenltZSwgYXPCoHBIIHJpc2VzIGZyb20gMiB0byAzLCBlbnp5bWUgYWN0aXZpdHkgZGVjcmVhc2VzLg==[Qq]

[f]RXhjZWxsZW50LsKgRm9yIHRoaXMgZW56eW1lLCBhc8KgcEggcmlzZXMgZnJvbSAyIHRvIDMsIGVuenltZSBhY3Rpdml0eSA=ZGVjcmVhc2VzLg==[Qq]

[q]Note that in this graph, the higher up we go on the Y axis, the more the enzyme is interacting with its substrate and changing it into the product. Notice that the highest level is pH 2. Another way of saying this is that pH 2 is the pH optimum (the best pH for this enzyme).

What happens at any pH that is lower than 2?

[c]RW56eW1lIGFjdGl2aXR5IHJpc2Vz[Qq]

[c]RW56eW1lIGFjdG l2aXR5IGZhbGxz[Qq]

[c]RW56eW1lIGFjdGl2aXR5IHN0YXlzIHRoZSBzYW1lLg==[Qq]

[f]Tm8uIElmIHlvdSBtb3ZlIGZyb20gMiB0byAxLCBpcyB0aGUgbGluZSBzbG9waW5nIHVwd2FyZHMgKG1vcmUgYWN0aXZpdHkpb3IgZG93bndhcmRzIChsZXNzIGFjdGl2aXR5KT8=[Qq]

[f]Q29ycmVjdC4gRW56eW1lIGFjdGl2aXR5IGZhbGxzIGFzIHRoZSBwSCBkcm9wcyBiZWxvdyAyLg==[Qq]

[f]Tm8uIElmIGVuenltZSBhY3Rpdml0eSBzdGF5ZWQgdGhlIHNhbWUsIHRoZW4gdGhlIGxpbmUgd291bGQgYmUgZmxhdC4gV2hhdCYjODIxNztzIGhhcHBlbmluZyB0byB0aGUgbGluZT8=[Qq]

[q]What’s the optimum pH for the enzyme shown in this graph (only choose values shown on the graph’s X-axis).

[textentry single_char=”true”]

[c]MQ ==[Qq]

[f]RXhjZWxsZW50LiBUaGUgb3B0aW1hbCBwSCBmb3IgdGhpcyBlbnp5bWUgaXMgYWJvdXQgMS4=[Qq]

[c]Kg==[Qq]

[f]Tm8uIEp1c3QgZmluZCB0aGUgcG9pbnQgb24gdGhlIFgtYXhpcyB3aGVyZSB0aGUgcmF0ZSBvZiBlbnp5bWUgYWN0aXZpdHkgaXMgdGhlIGhpZ2hlc3Qu[Qq]

[q]The stomach is a highly acidic environment. What would you predict would be the optimum pH for an enzyme that operates in the stomach?

[c]IDEgJiM4MjExOy AyIMKgIMKgIMKg[Qq][c]NSAmIzgyMTE7IDcgwqAgwqAgwqA=[Qq][c]IDggJiM4MjExOyA5IMKgIMKgIA==[Qq][c]MTIgJiM4MjExOyAxNA==

Cg==[Qq]

[f]RXhjZWxsZW50LiBGb3IgYW4gZW56eW1lIHRvIG9wZXJhdGUgaW4gdGhlIHN0b21hY2gsIGl0cyBwSCBvcHRpbXVtIHdvdWxkIGhhdmUgdG8gYmUgMSAmIzgyMTE7IDIu[Qq]

[f]Tm8uIHBIIDUgJiM4MjExOyA2IGlzIG1pbGRseSBhY2lkaWMsIGFuZCA3IGlzIG5ldXRyYWwuIEZpbmQgYSBzdHJvbmdseSBhY2lkaWMgcEggKHRoZSBraW5kIG9mIGVudmlyb25tZW50IHlvdSYjODIxNztkIGZpbmQgaW4gdGhlIHN0b21hY2gpLg==[Qq]

[f]Tm8uIHBIIDggJiM4MjExOyA5IGlzIG1pbGRseSBiYXNpYy4gRmluZCBhIHN0cm9uZ2x5IGFjaWRpYyBwSCAodGhlIGtpbmQgb2YgZW52aXJvbm1lbnQgeW91JiM4MjE3O2QgZmluZCBpbiB0aGUgc3RvbWFjaCku[Qq]

[f]Tm8uIHBIIDEyICYjODIxMTsgMTQgaXMgc3Ryb25nbHkgYmFzaWMuIEZpbmQgYSBzdHJvbmdseSBhY2lkaWMgcEggKHRoZSBraW5kIG9mIGVudmlyb25tZW50IHlvdSYjODIxNztkIGZpbmQgaW4gdGhlIHN0b21hY2gpLg==[Qq]

[q]The small intestine is a slightly basic environment. What would you predict would be the optimum pH for an enzyme that operates in the small intestine?

[c]IDEgJiM4MjExOyAyIMKgIMKgIMKg[Qq][c]NSAmIzgyMTE7IDbCoCDCoCDCoCA=[Qq][c]IDctOMKg IMKgIMKg[Qq][c]MTIgJiM4MjExOyAxNA==

Cg==[Qq]

[f]Tm8uIHBIIDEgJiM4MjExOyAyIGlzIHN0cm9uZ2x5IGFjaWRpYy4gUmVtZW1iZXIgdGhhdCBvbiB0aGUgcEggc2NhbGUsIDcgaXMgbmV1dHJhbCBhbmQgaGlnaGVyIHRoYW4gNyBpcyBpbmNyZWFzaW5nbHkgYmFzaWMuIFdoaWNoIHBIIHJhbmdlIHF1YWxpZmllcyBhcyBzbGlnaHRseSBiYXNpYz8=[Qq]

[f]Tm8uIHBIIDUgJiM4MjExOyA2IGlzIG1pbGRseSBhY2lkaWMuIFJlbWVtYmVyIHRoYXQgb24gdGhlIHBIIHNjYWxlLCA3IGlzIG5ldXRyYWwgYW5kIGhpZ2hlciB0aGFuIDcgaXMgaW5jcmVhc2luZ2x5IGJhc2ljLiBXaGljaCBwSCByYW5nZSBxdWFsaWZpZXMgYXMgc2xpZ2h0bHkgYmFzaWM/[Qq]

[f]WWVzLiBwSCA3wqAmIzgyMTE7IDjCoGlzIG1pbGRseSBiYXNpYywgYW5kIHRoYXQgaXMgYW4gb3B0aW11bSBwSCBmb3IgZW56eW1lcyBhdCB3b3JrIGluIHRoZSBtaWxkbHkgYmFzaWMgZW52aXJvbm1lbnQgb2YgdGhlIHNtYWxsIGludGVzdGluZXMu[Qq]

[f]Tm8uIHBIIDEyICYjODIxMTsgMTQgaXMgc3Ryb25nbHkgYmFzaWMuIFJlbWVtYmVyIHRoYXQgb24gdGhlIHBIIHNjYWxlLCA3IGlzIG5ldXRyYWwgYW5kIGhpZ2hlciB0aGFuIDcgaXMgaW5jcmVhc2luZ2x5IGJhc2ljLiBXaGljaCBwSCByYW5nZSBxdWFsaWZpZXMgYXMgc2xpZ2h0bHkgYmFzaWM/[Qq]

[q]Enzymes are also affected by temperature. The typical relationship between temperature and enzyme activity is shown on the left. Let’s start with what happens when enzymes are in cold environments. Which number on the graph shows an enzyme in a cold environment?

[textentry single_char=”true”]

[c]MQ ==[Qq]

[f]VGhhdCYjODIxNztzIGNvcnJlY3QuIFRoZSBhcnJvdyBwb2ludGluZyB0byB0aGUgcmlnaHQgb24gdGhlIFgtYXhpcyBpbmRpY2F0ZXMgdGhhdCB0aGUgdGVtcGVyYXR1cmUgaXMgaW5jcmVhc2luZyBhcyB5b3UgbW92ZSB0byB0aGUgcmlnaHQuIFRoZXJlZm9yZSBwb2ludCAxIHdvdWxkIGhhdmUgdG8gYmUgdGhlIGNvbGRlc3QgdGVtcGVyYXR1cmUu[Qq]

[c]Kg==[Qq]

[f]Tm8uIFRoZSBhcnJvdyBwb2ludGluZyB0byB0aGUgcmlnaHQgb24gdGhlIFgtYXhpcyBpbmRpY2F0ZXMgdGhhdCB0aGUgdGVtcGVyYXR1cmUgaXMgaW5jcmVhc2luZyBhcyB5b3UgbW92ZSB0byB0aGUgcmlnaHQuIFRoZXJlZm9yZSBwb2ludCAxIHdvdWxkIGhhdmUgdG8gYmUgdGhlIGNvbGRlc3QgdGVtcGVyYXR1cmUu[Qq]

[q labels = “top”]In cold temperatures, enzymes won’t ___________ much. That’s because “cold” means that the molecules aren’t __________. There’s very little chance that the enzyme will bump into its _____________ and be able to catalyze its reaction. This low level of activity due to cold is shown at number 1.

[l]substrate

[fx] No. Please try again.

[f*] Great!

[l]catalyze

[fx] No. Please try again.

[f*] Good!

[l]moving

[fx] No, that’s not correct. Please try again.

[f*] Good!

[q]As temperatures increase, molecules start to move faster. Collisions between enzyme and substrate increase in frequency. The rising line between 1 and 2 represents this increase in activity.

Which number shows the maximum activity and the optimal temperature for this enzyme?

[c]MSDCoCDCoA==[Qq][c]MiDCoC DCoA==[Qq][c]Mw==

Cg==[Qq]

[f]Tm8uIEF0IHBvaW50IDEsIHRoZSB0ZW1wZXJhdHVyZSBpcyBsb3cgKFgtYXhpcykgYW5kIGVuenltZSBhY3Rpdml0eSBpcyBsb3cgKFktYXhpcyku[Qq]

[f]WWVzLiBBdCBwb2ludCAyLCB0aGUgdGVtcGVyYXR1cmUgaXMgYXQgaXRzIG9wdGltYWwgcG9pbnQsIGFuZCBlbnp5bWUgYWN0aXZpdHkgaXMgYXQgaXRzIGhpZ2hlc3Qu[Qq]

[f]Tm8uIEF0IHBvaW50IDMsIHRoZSB0ZW1wZXJhdHVyZSBpcyBoaWdoIChYLWF4aXMpIGFuZCBlbnp5bWUgYWN0aXZpdHkgaXMgbG93IChZLWF4aXMp[Qq]

[q]Point 2 is directly above the ___________ temperature for this enzyme (use the adjective)

[textentry]

[c]b3B0aW1hbDsg b3B0aW11bQ==[Qq]

[f]VGhhdCYjODIxNztzIHJpZ2h0LiBQb2ludCAyIGlzIGRpcmVjdGx5IGFib3ZlIHRoZSBvcHRpbWFsIChvciBvcHRpbXVtKSB0ZW1wZXJhdHVyZS4=[Qq]

[c]Kg==[Qq]

[f]Tm8uwqBQb2ludCAyIGlzIGRpcmVjdGx5IGFib3ZlIHRoZSBvcHRpbWFsIChvciBvcHRpbXVtKSB0ZW1wZXJhdHVyZS4=[Qq]

[q labels = “top”]At point 2, the enzyme is operating at its optimal rate, converting as much ___________ as it can into the product. However, if the temperature rises too much, the enzyme gets ____________ by the heat (much like cooking meat changes its character, too much heat changes the enzyme). At that point, the enzyme can’t _______ with its substrate, and its activity falls to zero.

Denaturation of enzymes is closely related to the body’s need for ________________ : your body’s need to maintain consistent internal conditions. Your kidneys, for example, are constantly adjusting the pH of your blood. Your skin and circulatory system work to keep your temperature constant. It’s all to keep your __________ operating at an optimal level.

[l]bind

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]denatured

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]enzymes

[fx] No. Please try again.

[f*] Great!

[l]homeostasis

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]substrate

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[q]To review. If an enzyme is denatured in a permanent way, it’s called [hangman] denaturation. If the enzyme can return to its former state, then the denaturation was [hangman]

[c]aXJyZXZlcnNpYmxl[Qq]

[c]cmV2ZXJzaWJsZS4=[Qq]

[q]Another environmental factor is substrate concentration. In the graph below, that’s represented by “[S].”

At low substrate concentrations, shown as “Low [S]” in the left third of the graph, the probability of the enzyme meeting the substrate to catalyze the reaction is low, and the product will be produced at a low rate. As substrate concentration increases (Medium [S]), the collision and the reaction rate will increase.

Eventually, the enzymes become saturated. That means that there’s so much substrate that every enzyme’s active site will be bound to a substrate. At that point — the saturation point — the reaction will reach a maximum rate (and the rate flattens out).

[q]In the diagram on the left, the maximum rate of enzyme activity is at

[c]TG93IFtTXQ==[Qq]

[f]Tm8uIE5vdGUgdGhlIHJlbGF0aW9uc2hpcCBiZXR3ZWVuIHRoZSBYLWF4aXMgYW5kIHRoZSBZLWF4aXMuIFdoZW4gdGhlIHN1YnN0cmF0ZSBjb25jZW50cmF0aW9uIGlzIGxvdywgc28gaXMgdGhlIHJlYWN0aW9uIHJhdGUu[Qq]

[c]TWVkaXVtIFtTXQ==[Qq]

[f]Tm8uIEF0IE1lZGl1bSBbU10sIHRoZSByZWFjdGlvbiByYXRlIChvbiB0aGUgWS1heGlzKSBpcyBpbmNyZWFzaW5nLCBhbmQgdGhlbiBpdCBzdGFydHMgdG8gc2xvdyBkb3duLg==[Qq]

[c]SGlnaC BbU10=[Qq]

[f]TmljZSEgQXQgSGlnaCBbU10sIHRoZSByYXRlIG9mIGVuenltZSBhY3Rpdml0eSBpcyBhdCBpdHMgbWF4aW11bS4=[Qq]

[q]At High [S], the rate line has flattened out. That’s because every enzyme’s [hangman] site is occupied by the substrate. Another way to say that is that the enzymes are [hangman].

[c]YWN0aXZl[Qq]

[c]c2F0dXJhdGVk[Qq]

[q]A final point about enzymes and their environment. Sometimes, environmental change leads to irreversible denaturation. That’s like what happens to egg white when you cook it. It permanently changes form from liquid to solid. By contrast, some forms of denaturation are reversible. In that case, restoring the enzyme to its previous environmental optimum restores the enzyme’s activity.

[x][restart]

[/qwiz]

5. Enzymes Flashcards

The flashcards that follow will help you to master the following key terms related to enzymes.

[qdeck bold_text=”false”style=”width: 550px !important; min-height: 400px !important;”]

[h] Flashcards: Enzymes

[i] If you haven’t used a set of flashcards on Learn-Biology.com before, here’s what you need to know.

  • Click ‘Check Answer’ to see the answer to each card.
  • If you know it, click ‘Got it.”
  • If you don’t know it as well as you’d like, click ‘Need more practice,’ and that card will go to the bottom of the deck so you can practice it again.
  • ‘Shuffle’ lets you shuffle the deck.

[q]In relation to chemical reactions, compare reactants and products.

[a]In a chemical reaction, the substances that participate in the reaction are called reactants. The substances that result from the reaction are called products.

[q]What’s a catalyst? What’s the name for the catalysts found in living systems, and what kind of biomolecule are they?

[a]A catalyst is a substance that speeds up the rate of a chemical reaction. In living systems, the catalysts are enzymes, which are proteins.

[q]What’s activation energy? Sketch the energy profile of an energy-releasing reaction, showing the energy of the products, the energy of the reactants, and the activation energy.

[a]
The energy required to get a chemical reaction started is known as activation energy. A sketch of a typical energy-releasing reaction would look like what’s at left: “A” is the energy of the reactants, “B” is the energy of the products, “C” is the activation energy, and “E” is the energy released by the reaction.

 

[q]What’s an active site?

[a]The specific area on an enzyme where it binds with its substrate is called its active site, shown at “2” below.

[q]What’s an enzyme-substrate complex?
[a]At the moment when an enzyme binds with its substrate at the active site, it forms an enzyme-substrate complex. In the image below, the enzyme-substrate complex is at “4.”

[q]What’s the lock and key model of enzyme action? How is it different from induced fit?

[a]The lock and key model of enzyme action explains enzyme specificity. It’s the idea that an enzyme usually has only one substrate that which it can interact. The induced-fit model extends the lock and key idea by positing that in an enzyme-substrate complex, the active site of an enzyme will bend in a way that stresses the bonds of the substrate, causing the substrate to be transformed into the product.

[q json=”true” yy=”4″ unit=”3.Cellular_Energetics” dataset_id=”AP_Bio_Flashcards_2022|1cf4ea47c5910″ question_number=”92″ topic=”3.1-3.Enzymes”] Enzymes have a narrow set of conditions where they can function at or near their optimum. Explain.

[a] Enzymes are proteins. Their shape involves secondary and tertiary-level interactions, including hydrogen bonds, ionic bonds, and hydrophobic clustering. Changes in pH, temperature, or ion concentration interfere with these bonds, changing the shape of the active site, which can keep the enzyme from binding with its substrate. As a result, most enzymes have a pH, ionic, or temperature optimum at which the shape of their active site best fits their substrate. Changing this optimum causes denaturation: a change in the shape that lowers (or completely negates) the enzyme’s function.

[q json=”true” yy=”4″ unit=”3.Cellular_Energetics” dataset_id=”AP_Bio_Flashcards_2022|1ce9460c51910″ question_number=”93″ topic=”3.1-3.Enzymes”] Describe how enzyme activity is affected by changes in the pH of its environment. Include the concept of “denaturation” in your answer, and draw a sketch of the relation between pH and enzyme activity.

[a] Most enzymes have a pH optimum where they operate at peak efficiency. As the pH moves above or below the optimum, enzyme performance drops. A graph of enzyme efficiency plotted against pH shows a peak at the optimum, and then a drop off at either side as the enzyme becomes denatured.

 

[q json=”true” yy=”4″ unit=”3.Cellular_Energetics” topic=”3.1-3.Enzymes” dataset_id=”AP_Bio_Flashcards_2022|1c490d7e6b86c5″ question_number=”94″] Describe how enzyme activity is affected by changes in the temperature of enzyme’s environment. Include the concept of “denaturation” in your answer, and draw a sketch showing the relationship between temperature and enzyme activity.

[a] Up to a certain point, enzyme activity increases with temperature, because more kinetic energy increases molecular motion and increases the chance that the enzyme will bind with its substrate(s). At a certain temperature (beyond 2 in the graph), the enzyme denatures, disrupting the enzyme’s catalytic abilities.

[q]Explain how enzyme activity is affected by substrate concentration.

[a]At low substrate concentrations, the probability of the enzyme meeting the substrate to catalyze the reaction is low, and the product will be produced at a low rate. As substrate concentration increases, the collision and the reaction rate will increase. Eventually, the saturation point is reached, and the reaction will reach a maximum rate.

[x]

If you want more practice, please press the button below.
[restart]
[/qdeck]

6. Enzymes Music video

Almost everything you learned above is reviewed in the video below. Enjoy!

7. An Enzymes Quiz

[qwiz style=”width: 550px !important; min-height: 400px !important;”]

[h] Quiz: Enzymes
[i] Here’s how the quiz works:

  • Questions are multiple-choice or hangman/fill-in-the-blank style, but the entire quiz is like a series of flashcards.
  • If you get the question right, it comes off the stack.
  • If you get the question wrong, it goes to the bottom of the stack, so you can try it again.

[q labels = “top”] Use the choices below to label the enzyme, the substrate, and the enzyme-substrate complex.

[l]enzyme

[fx] No, that’s not correct.  Please try again.

[f*] Correct!

[l]enzyme-substrate complex

[fx] No, that’s not correct.  Please try again.

[f*] Correct!

[l]product

[fx] No.  Please try again.

[f*] Great!

[l]substrate

[fx] No, that’s not correct.  Please try again.

[f*] Good!

[q] Enzymes almost always belong to which family of macromolecules?

[c]IGNhcmJvaHlkcmF0ZXM=[Qq]

[c]IGxpcGlkcw==[Qq]

[c]IHByb3 RlaW5z[Qq]

[f]IFRoYXTigJlzIG5vdCBjb3JyZWN0LiBUaGluayBvZiB0aGUgbWFjcm9tb2xlY3VsZSB3aXRoIHRoZSBtb3N0IGNvbXBsZXggc2hhcGUgYW5kIHN0cnVjdHVyZSwgYW5kIHlvdeKAmWxsIGhhdmUgdGhlIGFuc3dlci4=[Qq]

[f]IE5vLiBMaXBpZHMgYXJlIHVzZWQgZm9yIGVuZXJneSBzdG9yYWdlLCBpbnN1bGF0aW9uLCBhbmQgd2F0ZXJwcm9vZmluZywgYnV0IHRoZXkgZG9u4oCZdCBhY3QgYXMgZW56eW1lcy4=wqAgVGhpbmsgb2YgdGhlIG1hY3JvbW9sZWN1bGUgd2l0aCB0aGUgbW9zdCBjb21wbGV4IHNoYXBlIGFuZCBzdHJ1Y3R1cmUsIGFuZCB5b3XigJlsbCBoYXZlIHRoZSBhbnN3ZXIu[Qq]

[f]IEV4YWN0bHkuIEFsbW9zdCBhbGwgZW56eW1lcyBhcmUgcHJvdGVpbnMu

Cg==

[Qq]

[q] The thing an enzyme acts upon is called a (n)

[c]IHByb2R1Y3Q=[Qq]

[c]IHRhcmdldA==[Qq]

[c]IHJlYWN0YW50[Qq]

[c]IHN1YnN0 cmF0ZQ==[Qq]

[f]IE5vLiBBbiBlbnp5bWUgY2F0YWx5emVzIGEgcmVhY3Rpb24sIGFuZCBhIHByb2R1Y3QgaXMgd2hhdCByZXN1bHRzLg==[Qq]

[f]IE5vLiBXaGlsZSDigJh0YXJnZXTigJkgaXMgYSBsb2dpY2FsIGNob2ljZSwgdGhlcmXigJlzIGEgc3BlY2lhbCB3b3JkIGZvciB0aGUgc3Vic3RhbmNlIHRoYXQgYW4gZW56eW1lIGFjdHMgdXBvbi4=[Qq]

[f]IE5vLiBUaGF04oCZcyBhIHZlcnkgbG9naWNhbCBhbmQgZ2VuZXJhbCBjaG9pY2UsIGJ1dCB0aGVyZeKAmXMgYSBtb3JlIHNwZWNpZmljIGFuc3dlci4=[Qq]

[f]IEV4YWN0bHkuIEVuenltZXMgYWN0IHVwb24gc3Vic3RyYXRlcy4=

Cg==

[Qq]

[q] From the choices below, choose the best match: Enzymes fit with their substrates as a _______________ fits with a __________________.

[c]IGFzIGEgd2hlZWwgZml0cyB3aXRoIGEgcm9hZC4=[Qq]

[c]IGFzIGEgaGFybW9ueSBmaXRzIHdpdGggYSBzb25nLg==[Qq]

[c]IGFzIGEgZmxvd2VyIGZpdHMgd2l0aCBhIGJvdXF1ZXQu[Qq]

[c]IGFzIGEgZG9nIGZpdHMgd2l0aCBhIGNhdC4=[Qq]

[c]IGFzIGxvY2sgZml0 cyB3aXRoIGtleQ==[Qq]

[f]IE5vLiBNYW55IGRpZmZlcmVudCBraW5kcyBvZiB3aGVlbHMgZml0IHdpdGggbWFueSBkaWZmZXJlbnQga2luZHMgb2Ygcm9hZHMuIFRoZSBrZXkgaWRlYXMgaGVyZSBhcmUgc3BlY2lmaWNpdHkgYW5kIGNvbXBsZW1lbnRhcnkgc2hhcGUu[Qq]

[f]IE5vLiBNYW55IGtpbmRzIG9mIGhhcm1vbmllcyBjYW4gd29yayB3aXRoIGFueSBvbmUgcGFydGljdWxhciBzb25nIChiYXNlZCBvbiB0aGUgYXJ0aXN04oCZcyBwcmVmZXJlbmNlKS4gVGhlIGtleSBpZGVhcyBoZXJlIGFyZSBzcGVjaWZpY2l0eSBhbmQgY29tcGxlbWVudGFyeSBzaGFwZS4=[Qq]

[f]IE5vLiBNYW55IGRpZmZlcmVudCB0eXBlcyBvZiBmbG93ZXJzIGNhbiB3b3JrIGluIGEgYm91cXVldCAoYmFzZWQgb24gdGhlIGZsb3Jpc3TigJlzIHByZWZlcmVuY2UpLiBUaGUga2V5IGlkZWFzIGhlcmUgYXJlIHNwZWNpZmljaXR5IGFuZCBjb21wbGVtZW50YXJ5IHNoYXBlLg==[Qq]

[f]IE5vISBEb2dzIGRvbuKAmXQgZml0IHdpdGggY2F0cyAoYXQgbGVhc3QsIG5vdCB1c3VhbGx5KS4gVGhlIGtleSBpZGVhcyBoZXJlIGFyZSBzcGVjaWZpY2l0eSBhbmQgY29tcGxlbWVudGFyeSBzaGFwZS4=[Qq]

[f]IFJpZ2h0LiBJbiB0aGUgc2FtZSB3YXkgYXMgb25seSBvbmUgc3BlY2lhbGx5IGN1dCBrZXkgZml0cyBpbnRvIGEgbG9jaywgdGhlcmUgaXMgdXN1YWxseSBhIG9uZS10by1vbmUgcmVsYXRpb25zaGlwIGJldHdlZW4gZW56eW1lIGFuZCBzdWJzdHJhdGUsIGFuZCB0aGF0IHJlbGF0aW9uc2hpcCBpcyBiYXNlZCBvbiBjb21wbGVtZW50YXJ5IHNoYXBlLg==

Cg==

[Qq]

[q] The notion that an enzyme will change its shape to closely bind with and modify its substrate is called

[c]IG1vZGlmaWVkIGJpbmRpbmc=[Qq]

[c]IHN1YnN0cmF0ZSBhcHByb3hpbWF0aW9u[Qq]

[c]IGFkYXB0aXZlIGNvbmZvcm1hdGlvbg==[Qq]

[c]IGluZHVj ZWQgZml0[Qq]

[c]IGVuenltYXRpYyBhZGFwdGF0aW9u[Qq]

[f]IE5vLiBZb3VyIGNob2ljZSBpcyBhIHNlbnNpYmxlIGRlc2NyaXB0aW9uLCBidXQgdGhhdOKAmXMgbm90IHRoZSBuYW1lIG9mIHRoaXMgbW9kZWwgb2YgZW56eW1lLXN1YnN0cmF0ZSBpbnRlcmFjdGlvbi4gVGhlIGNvcnJlY3QgbmFtZSBvZiB0aGUgbW9kZWwgaGFzIHRvIGRvIHdpdGggYW4gaW1wcm92ZWQgZml0IGNvbWluZyBhYm91dCBiZXR3ZWVuIGVuenltZSBhbmQgc3Vic3RyYXRlLiBUaGluayBhYm91dCB0aGF0ICh3aGljaCwgYnkgdGhlIHdheSwgaW5jbHVkZXMgYSBodWdlIGhpbnQpIHRoZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==[Qq]

[f]IE5vLiBZb3VyIGNob2ljZSBpcyBhIHNlbnNpYmxlIGRlc2NyaXB0aW9uLCBidXQgdGhhdOKAmXMgbm90IHRoZSBuYW1lIG9mIHRoaXMgbW9kZWwgb2YgZW56eW1lLXN1YnN0cmF0ZSBpbnRlcmFjdGlvbi4gVGhlIGNvcnJlY3QgbmFtZSBvZiB0aGUgbW9kZWwgaGFzIHRvIGRvIHdpdGggYW4gaW1wcm92ZWQgZml0IGNvbWluZyBhYm91dCBiZXR3ZWVuIGVuenltZSBhbmQgc3Vic3RyYXRlLiBUaGluayBhYm91dCB0aGF0ICh3aGljaCwgYnkgdGhlIHdheSwgaW5jbHVkZXMgYSBodWdlIGhpbnQpIHRoZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==[Qq]

[f]IE5vLiBZb3VyIGNob2ljZSBpcyBhIHNlbnNpYmxlIGRlc2NyaXB0aW9uLCBidXQgdGhhdOKAmXMgbm90IHRoZSBuYW1lIG9mIHRoaXMgbW9kZWwgb2YgZW56eW1lLXN1YnN0cmF0ZSBpbnRlcmFjdGlvbi4gVGhlIGNvcnJlY3QgbmFtZSBvZiB0aGUgbW9kZWwgaGFzIHRvIGRvIHdpdGggYW4gaW1wcm92ZWQgZml0IGNvbWluZyBhYm91dCBiZXR3ZWVuIGVuenltZSBhbmQgc3Vic3RyYXRlLiBUaGluayBhYm91dCB0aGF0ICh3aGljaCwgYnkgdGhlIHdheSwgaW5jbHVkZXMgYSBodWdlIGhpbnQpIHRoZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==[Qq]

[f]IEV4YWN0bHkuIFRoZSBpZGVhIGhlcmUgaXMgdGhhdCB0aGUgYmluZGluZyBvZiBlbnp5bWUgYW5kIHN1YnN0cmF0ZSBpbmR1Y2VzIChjYXVzZXMpIGEgY2hhbmdlwqBpbiB0aGUgc2hhcGUgb2YgdGhlIGVuenltZeKAmXMgYWN0aXZlIHNpdGUsIHdoaWNoIGltcHJvdmVzIGl0cyBiaW5kaW5nIHdpdGggdGhlIHN1YnN0cmF0ZSBhbmQgYXNzaXN0cyBpdCBpbiBjb252ZXJ0aW5nIHRoZSBzdWJzdHJhdGUgaW50byB0aGUgcHJvZHVjdC4=[Qq]

[f]IE5vLiBZb3VyIGNob2ljZSBpcyBhIHNlbnNpYmxlIGRlc2NyaXB0aW9uLCBidXQgdGhhdOKAmXMgbm90IHRoZSBuYW1lIG9mIHRoaXMgbW9kZWwgb2YgZW56eW1lLXN1YnN0cmF0ZSBpbnRlcmFjdGlvbi4gVGhlIGNvcnJlY3QgbmFtZSBvZiB0aGUgbW9kZWwgaGFzIHRvIGRvIHdpdGggYW4gaW1wcm92ZWQgZml0IGNvbWluZyBhYm91dCBiZXR3ZWVuIGVuenltZSBhbmQgc3Vic3RyYXRlLiBUaGluayBhYm91dCB0aGF0ICh3aGljaCwgYnkgdGhlIHdheSwgaW5jbHVkZXMgYSBodWdlIGhpbnQpIHRoZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==

Cg==

[Qq]

[q] An enzyme binds its substrate at its

[c]IHJlYWN0aW9uIHNpdGU=[Qq]

[c]IGJpbmRpbmcgc2l0ZQ==[Qq]

[c]IGFjdGl2 ZSBzaXRl[Qq]

[f]IE5vLiDigJhSZWFjdGlvbiBzaXRl4oCZIGlzIGEgbG9naWNhbCBjaG9pY2UsIGJ1dCBub3QgdGhlIG9uZSB0aGF04oCZcyB1c2VkLiBCZWNhdXNlIGFuIGVuenltZSBpcyBhIHRocmVlLWRpbWVuc2lvbmFsIG9iamVjdCwgb25seSBhIHNtYWxsIHBhcnQgb2YgaXRzIHN1cmZhY2UgaXMgZ29pbmcgdG8gYWN0aXZlbHkgdG91Y2ggdGhlIHN1YnN0cmF0ZSBhbmQgaW50ZXJhY3Qgd2l0aCBpdCBpbiBhIHdheSB0aGF0IGNhdGFseXplcyB0aGUgcmVhY3Rpb24uIFNlZSBpZiB5b3UgY2FuIGZpbmQgdGhlIGh1Z2UgaGludCBpbiB0aGUgcHJldmlvdXMgc2VudGVuY2UsIGFuZCB1c2UgaXQgdG8gYW5zd2VyIHRoaXMgY29ycmVjdGx5IG5leHQgdGltZS4=[Qq]

[f]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[Qq]

[f]IFRlcnJpZmljLiBUaGUgZW56eW1lIGJpbmRzIHdpdGggaXRzIHN1YnN0cmF0ZSBhdCBpdHMgYWN0aXZlIHNpdGUu

Cg==

[Qq]

[q] The relationship in shape between enzyme and substrate is best described as

[c]IGNvbXBsZW 1lbnRhcnk=[Qq]

[c]IGNvbnRyYXN0aW5n[Qq]

[c]IGEgbWlycm9yIGltYWdl[Qq]

[c]IGhhcm1vbmlvdXM=[Qq]

[f]IEV4YWN0bHkuIFRoZSBzaGFwZSBvZiBhbiBlbnp5bWUgZml0cyB3aXRoIHRoZSBzaGFwZSBvZiBhIHN1YnN0cmF0ZSBpbiBhIGNvbXBsZW1lbnRhcnkgd2F5LCBsaWtlIHR3byBwaWVjZXMgb2YgYSBwdXp6bGUu[Qq]

[f]IE5vLiBUcnkgdG8gZmluZCBhIHdvcmQgdGhhdCBjb252ZXlzIHRoZSBpZGVhIHRoYXQgZW56eW1lcyBmaXQgd2l0aCB0aGVpciBzdWJzdHJhdGVzIGxpa2UgcGllY2VzIG9mIGEgcHV6emxlIGZpdCB0b2dldGhlci4=[Qq]

[f]IE5vLiBUaGUgc2hhcGUgb2YgYW4gZW56eW1lIGFuZCBhIHN1YnN0cmF0ZSBmaXQgdG9nZXRoZXIsIGJ1dCB0aGV54oCZcmUgbm90IG1pcnJvciBpbWFnZXMuIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSB3b3JkIHRoYXQgY29udmV5cyB0aGlzIOKAmGZpdHRpbmcgdG9nZXRoZXIu4oCZ[Qq]

[f]IE5vLCBidXQgdGhhdOKAmXMgYW4gaW50ZXJlc3RpbmcgY2hvaWNlLiBTb3VuZHMgdGhhdCBmaXQgdG9nZXRoZXIgYXJlIGhhcm1vbmlvdXMuIEJ1dCB0aGVyZeKAmXMgYSBjaG9pY2UgdGhhdCBiZXR0ZXIgY29udmV5cyB0aGUgbWF0Y2hpbmcgZml0IGJldHdlZW4gZW56eW1lIGFuZCBzdWJzdHJhdGUu

Cg==

[Qq]

[q] If you added 4 milligrams of an enzyme to a reaction, and were able to recover all of the available enzymes at the reaction’s end, how much enzyme should you be able to recover?

[c]IDQgbWlsbG lncmFtcw==[Qq]

[c]IDIgbWlsbGlncmFtcw==[Qq]

[c]IDggbWlsbGlncmFtcw==[Qq]

[c]IDAgbWlsbGlncmFtcw==[Qq]

[f]IFRoYXTigJlzIHJpZ2h0LiBFbnp5bWVzIGFyZSBjYXRhbHlzdHMgdGhhdCBhcmUgbm90IGNvbnN1bWVkIGluIHRoZSByZWFjdGlvbnMgdGhleSBwYXJ0aWNpcGF0ZSBpbi4gVGhlcmVmb3JlLCBpbiB0aGUgZW5kLCB5b3Ugc2hvdWxkIGJlIGFibGUgdG8gcmVjb3ZlciBhbGwgb2YgdGhlIGVuenltZXMgdGhhdCB5b3UgaGFkIGF0IHRoZSBzdGFydC4=[Qq]

[f]IE5vLiBFbnp5bWVzIGFyZSBjYXRhbHlzdHMgdGhhdCBhcmUgbm90IGNvbnN1bWVkIGluIHRoZSByZWFjdGlvbnMgdGhleSBwYXJ0aWNpcGF0ZSBpbi4gVGhlcmVmb3JlLCBpbiB0aGUgZW5kLCB5b3Ugc2hvdWxkIGJlIGFibGUgdG8gcmVjb3ZlciBhbGwgb2YgdGhlIGVuenltZXMgdGhhdCB5b3UgaGFkIGF0IHRoZSBzdGFydC4=[Qq]

[f]IE5vLiBFbnp5bWVzIGFyZSBjYXRhbHlzdHMgdGhhdCBhcmUgbm90IGNvbnN1bWVkIGluIHRoZSByZWFjdGlvbnMgdGhleSBwYXJ0aWNpcGF0ZSBpbi4gVGhlcmVmb3JlLCBpbiB0aGUgZW5kLCB5b3Ugc2hvdWxkIGJlIGFibGUgdG8gcmVjb3ZlciBhbGwgb2YgdGhlIGVuenltZXMgdGhhdCB5b3UgaGFkIGF0IHRoZSBzdGFydC4=[Qq]

[f]IE5vLiBFbnp5bWVzIGFyZSBjYXRhbHlzdHMgdGhhdCBhcmUgbm90IGNvbnN1bWVkIGluIHRoZSByZWFjdGlvbnMgdGhleSBwYXJ0aWNpcGF0ZSBpbi4gVGhlcmVmb3JlLCBpbiB0aGUgZW5kLCB5b3Ugc2hvdWxkIGJlIGFibGUgdG8gcmVjb3ZlciBhbGwgb2YgdGhlIGVuenltZXMgdGhhdCB5b3UgaGFkIGF0IHRoZSBzdGFydC4=

Cg==

[Qq]

[q] In the diagram below that shows the progress of two chemical reactions, which number shows the pathway of the reaction when it’s catalyzed by an enzyme?

[c]IDEgwqDCoA==[Qq][c]IDIgwq DCoA==[Qq][c]IDMgwqDCoA==[Qq][c]IDQ=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSBzaG93cyB0aGUgcHJvZ3Jlc3Mgb2YgYSBub24tZW56eW1lIGNhdGFseXplZCByZWFjdGlvbi4gWW91IGNhbiB0ZWxsIGJlY2F1c2UgdGhlIGFjdGl2YXRpb24gZW5lcmd5IHJlcXVpcmVkIHRvIGdldCB0aGUgcmVhY3Rpb24gZ29pbmcgKHNob3duIGF0IDQpIGlzIG11Y2ggaGlnaGVyIHRoYW4gdGhlIGFjdGl2YXRpb24gZW5lcmd5IHJlcXVpcmVkIHdpdGggYW4gZW56eW1lIChzaG93biBhdCAzKS4gS2VlcCB0aGF0IGluIG1pbmQgd2hlbiB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24gYWdhaW4u[Qq]

[f]IEV4Y2VsbGVudCEgTnVtYmVyIDIgc2hvd3MgdGhlIHByb2dyZXNzIG9mIGFuIGVuenltZS1jYXRhbHl6ZWQgcmVhY3Rpb24uIFlvdSBjYW4gdGVsbCBiZWNhdXNlIHRoZSBhY3RpdmF0aW9uIGVuZXJneSByZXF1aXJlZCB0byBnZXQgdGhlIHJlYWN0aW9uIGdvaW5nIChzaG93biBhdCAzKSBpcyBtdWNoIGxvd2VyIHRoYW4gdGhlIGFjdGl2YXRpb24gZW5lcmd5IHdvdWxkIGJlIHdpdGhvdXQgYW4gZW56eW1lIChzaG93biBhdCA0KS4gTG93ZXJpbmcgYWN0aXZhdGlvbiBlbmVyZ3kgaXMgZXhhY3RseSB3aGF0IGVuenltZXMgZG8u[Qq]

[f]IE5vLCBidXQgeW914oCZcmUgb24gdGhlIHJpZ2h0IHRyYWNrLiBOdW1iZXIgMyBpcyBzaG93aW5nIHRoZSByZWR1Y2VkIGFtb3VudCBvZiBlbmVyZ3kgcmVxdWlyZWQgdG8gc3RhcnQgYSByZWFjdGlvbiAoYWN0aXZhdGlvbiBlbmVyZ3kpIHdoZW4gYW4gZW56eW1lIGlzIHByZXNlbnQgKGNvbXBhcmUgMyB0byA0KS4gS2VlcCB0aGF0IGluIG1pbmQgd2hlbiB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24gYWdhaW4u[Qq]

[f]IE5vLiBOdW1iZXIgNCBzaG93cyB0aGUgYWN0aXZhdGlvbiBlbmVyZ3kgcmVxdWlyZWQgd2hlbiBhbiBlbnp5bWUgaXNu4oCZdCBjYXRhbHl6aW5nIGEgcmVhY3Rpb24uIFRoZSBtYWluIGVmZmVjdCBvZiBhbiBlbnp5bWUgaXMgdG8gbG93ZXIgYWN0aXZhdGlvbiBlbmVyZ3kgKGNvbXBhcmUgbnVtYmVyIDQgdG8gbnVtYmVyIDMpLiBLZWVwIHRoYXQgaW4gbWluZCB3aGVuIHlvdSBzZWUgdGhpcyBxdWVzdGlvbiBhZ2Fpbi4=

Cg==

[Qq]

[q] In the diagram below that shows the progress of two chemical reactions, which number shows the activation energy of the enzyme-catalyzed reaction.

[c]IDEgwqAgwqA=[Qq][c]IDIgwqAgwqDCoA==[Qq][c]IDMgwq DCoA==[Qq][c]IDQ=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSBzaG93cyB0aGUgcHJvZ3Jlc3Mgb2YgYSBub24tZW56eW1lIGNhdGFseXplZCByZWFjdGlvbi4gWW91IGNhbiB0ZWxsIGJlY2F1c2UgdGhlIGFjdGl2YXRpb24gZW5lcmd5IHJlcXVpcmVkIHRvIGdldCB0aGUgcmVhY3Rpb24gZ29pbmcgKHNob3duIGF0IDQpIGlzIHNvIGhpZ2guIE5vdywga25vd2luZyB3aGF0IG51bWJlciA0IGlzLCBzZWUgaWYgeW91IGNhbiBmaWd1cmUgb3V0IHRoZSBhbnN3ZXIgdG8gdGhpcyBxdWVzdGlvbiB3aGVuIHlvdSBzZWUgaXQgYWdhaW4u[Qq]

[f]IE5vLiBOdW1iZXIgMiBzaG93cyB0aGUgcHJvZ3Jlc3Mgb2YgYW4gZW56eW1lLWNhdGFseXplZCByZWFjdGlvbi4gWW91IGNhbiB0ZWxsIGJlY2F1c2UgdGhlIGFjdGl2YXRpb24gZW5lcmd5IHJlcXVpcmVkIHRvIGdldCB0aGUgcmVhY3Rpb24gZ29pbmcgaXMgbXVjaCBsb3dlciB0aGFuIHRoZSBhY3RpdmF0aW9uIGVuZXJneSB3b3VsZCBiZSB3aXRob3V0IGFuIGVuenltZSAoc2hvd24gYXQgNCkuIFdpdGggdGhhdCBoaW50LCBzZWUgaWYgeW91IGNhbiBnZXQgdGhpcyBxdWVzdGlvbiByaWdodCB3aGVuIHlvdSBzZWUgaXQgYWdhaW4u[Qq]

[f]IEZhbnRhc3RpYy4gTnVtYmVyIDMgaXMgc2hvd2luZyB0aGUgcmVkdWNlZCBhbW91bnQgb2YgZW5lcmd5IHJlcXVpcmVkIHRvIHN0YXJ0IGEgcmVhY3Rpb24gKGFjdGl2YXRpb24gZW5lcmd5KSB3aGVuIGFuIGVuenltZSBpcyBwcmVzZW50IChjb21wYXJlIDMgdG8gNCku[Qq]

[f]IE5vLiBOdW1iZXIgNCBzaG93cyB0aGUgYWN0aXZhdGlvbiBlbmVyZ3kgcmVxdWlyZWQgd2hlbiBhbiBlbnp5bWUgaXNu4oCZdCBjYXRhbHl6aW5nIGEgcmVhY3Rpb24uIFRoZSBtYWluIGVmZmVjdCBvZiBhbiBlbnp5bWUgaXMgdG8gbG93ZXIgYWN0aXZhdGlvbiBlbmVyZ3kuIEtlZXAgdGhhdCBpbiBtaW5kIHdoZW4geW91IHNlZSB0aGlzIHF1ZXN0aW9uIGFnYWluLCBhbmQgeW91IHNob3VsZCBiZSBhYmxlIHRvIGZpZ3VyZSBpdCBvdXQu

Cg==

[Qq]

[q] In the graph below, which line would represent the reaction catalyzed by an enzyme?

[c]IDEgwq AgwqA=[Qq][c]IDI=

Cg==[Qq]

[f]IEV4YWN0bHkhIEVuenltZXMgc3BlZWQgdXAgcmVhY3Rpb24gcmF0ZXMuIFRoYXTigJlzIHdoeSB0aGUgc2xvcGUgb2YgbGluZSBvbmUgaXMgc3RlZXBlcjogbW9yZSBvZiB0aGUgcHJvZHVjdCBpcyBiZWluZyBjb252ZXJ0ZWQgdG8gdGhlIHN1YnN0cmF0ZSBvdmVyIHRpbWUu[Qq]

[f]IE5vLiBUaGUga2V5IGlkZWEgb2YgdGhpcyBncmFwaCBpcyB0aGF0IGVuenltZXMgbWFrZSByZWFjdGlvbnMgZ28gZmFzdGVyLiBMaW5lIG51bWJlciBvbmUgaGFzIGEgbGVzcyBzdGVlcCBzbG9wZSB0aGFuIGxpbmUgbnVtYmVyIDIsIGluZGljYXRpbmcgdGhhdCB0aGUgcmF0ZSBvZiBwcm9kdWN0IGNyZWF0aW9uIGlzIGxvd2VyLiBLZWVwIHRoYXQgaW4gbWluZCB3aGVuIHlvdSBzZWUgdGhpcyBxdWVzdGlvbiBhZ2Fpbi4=

Cg==

[Qq]

[q] In the diagram below, the enzyme-substrate complex is represented by

[c]IDEgwqAgwqA=[Qq][c]IDIgwqAgwqA=[Qq][c]IDMgwqAgwqA=[Qq][c]IDQgwq DCoA==[Qq][c]IDU=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSByZXByZXNlbnRzIHRoZSBlbnp5bWUuIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3MgdGhlIGVuenltZSBhbmQgdGhlIHN1YnN0cmF0ZSBjb21pbmcgdG9nZXRoZXIgdG8gZm9ybSBhbiBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgu[Qq]

[f]IE5vLiBOdW1iZXIgMiByZXByZXNlbnRzIHRoZSBhY3RpdmUgc2l0ZSwgd2hpY2ggaXMgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCBpdHMgc3Vic3RyYXRlLiBTZWUgaWYgeW91IGNhbiBmaW5kIGEgcGFydCBvZiB0aGUgZGlhZ3JhbSB0aGF0IHNob3dzIHRoZSBlbnp5bWUgYW5kIHRoZSBzdWJzdHJhdGUgY29taW5nIHRvZ2V0aGVyIHRvIGZvcm0gYW4gZW56eW1lLXN1YnN0cmF0ZSBjb21wbGV4Lg==[Qq]

[f]IE5vLiBOdW1iZXIgMyByZXByZXNlbnRzIHRoZSBzdWJzdHJhdGUuIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3MgdGhlIGVuenltZSBhbmQgdGhlIHN1YnN0cmF0ZSBjb21pbmcgdG9nZXRoZXIgdG8gZm9ybSBhbiBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgu[Qq]

[f]IEZhbnRhc3RpYyEgTnVtYmVyIDQgcmVwcmVzZW50cyB0aGUgZW56eW1lLXN1YnN0cmF0ZSBjb21wbGV4Lg==[Qq]

[f]IE5vLiBOdW1iZXIgNSByZXByZXNlbnRzIHRoZSBwcm9kdWN0cyBvZiB0aGUgcmVhY3Rpb24uIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3MgdGhlIGVuenltZSBhbmQgdGhlIHN1YnN0cmF0ZSBjb21pbmcgdG9nZXRoZXIgdG8gZm9ybSBhbiBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgu

Cg==

[Qq]

[q] In the diagram below, the active site is represented by

[c]IDEgwqAgwqA=[Qq][c]IDIgwq AgwqA=[Qq][c]IDMgwqAgwqA=[Qq][c]IDQgwqAgwqA=[Qq][c]IDU=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSByZXByZXNlbnRzIHRoZSBlbnRpcmUgZW56eW1lLiBTZWUgaWYgeW91IGNhbiBmaW5kIGEgcGFydCBvZiB0aGUgZGlhZ3JhbSB0aGF0IHNob3dzIHdoZXJlIHRoZSBlbnp5bWUgd2lsbCBiaW5kIHdpdGggdGhlIHN1YnN0cmF0ZS4=[Qq]

[f]IEF3ZXNvbWUhIE51bWJlciAyIHJlcHJlc2VudHMgdGhlIGFjdGl2ZSBzaXRlLCB3aGljaCBpcyB3aGVyZSB0aGUgZW56eW1lIHdpbGwgYmluZCB3aXRoIGl0cyBzdWJzdHJhdGUu[Qq]

[f]IE5vLiBOdW1iZXIgMyByZXByZXNlbnRzIHRoZSBzdWJzdHJhdGUuIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3Mgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCB0aGUgc3Vic3RyYXRlLg==[Qq]

[f]IE5vLiBOdW1iZXIgNCByZXByZXNlbnRzIHRoZSBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXguIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3Mgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCB0aGUgc3Vic3RyYXRlLg==[Qq]

[f]IE5vLiBOdW1iZXIgNSByZXByZXNlbnRzIHRoZSBwcm9kdWN0cyBvZiB0aGUgcmVhY3Rpb24uIFNlZSBpZiB5b3UgY2FuIGZpbmQgYSBwYXJ0IG9mIHRoZSBkaWFncmFtIHRoYXQgc2hvd3Mgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCBpdHMgc3Vic3RyYXRlLg==

Cg==

[Qq]

[q] In the diagram below, the enzyme is represented by

[c]IDEgwq AgwqA=[Qq][c]IDIgwqAgwqA=[Qq][c]IDMgwqAgwqA=[Qq][c]IDQgwqDCoA==[Qq][c]IDU=

Cg==[Qq]

[f]IFllcyEgTnVtYmVyIDEgcmVwcmVzZW50cyB0aGUgZW50aXJlIGVuenltZS4=[Qq]

[f]IE5vLiBOdW1iZXIgMiByZXByZXNlbnRzIHRoZSBhY3RpdmUgc2l0ZSwgd2hpY2ggaXMgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCBpdHMgc3Vic3RyYXRlLiBTZWUgaWYgeW91IGNhbiBmaW5kIHRoZSBudW1iZXIgd2hpY2ggcmVwcmVzZW50cyB0aGUgZW50aXJlIGVuenltZS4=[Qq]

[f]IE5vLiBOdW1iZXIgMyByZXByZXNlbnRzIHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIGFib3V0IHRvIGJpbmQgd2l0aCB0aGUgZW56eW1lLiBTZWUgaWYgeW91IGNhbiBmaW5kIHRoZSBudW1iZXIgd2hpY2ggcmVwcmVzZW50cyB0aGUgZW56eW1lLg==[Qq]

[f]IE5vLiBOdW1iZXIgNCByZXByZXNlbnRzIHRoZSBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgsIHdoaWNoIGluY2x1ZGVzIGJvdGggZW56eW1lIGFuZCBzdWJzdHJhdGUsIGF0IGEgbW9tZW50IHdoZW4gdGhlIHR3byBhcmUgdGVtcG9yYXJpbHkgYm9uZGVkIHRvZ2V0aGVyIGFzIHRoZSBlbnp5bWUgY2F0YWx5emVzIGl0cyByZWFjdGlvbi4gU2VlIGlmIHlvdSBjYW4gZmluZCB0aGUgbnVtYmVyIHdoaWNoIHJlcHJlc2VudHMganVzdCB0aGUgZW56eW1lLg==[Qq]

[f]IE5vLiBOdW1iZXIgNSByZXByZXNlbnRzIHRoZSBwcm9kdWN0cyBvZiB0aGUgcmVhY3Rpb24uIFRoZSBwcm9kdWN0cywgeW91IGNhbiBzZWUsIHdlcmUgZm9ybWVybHkgdGhlIHN1YnN0cmF0ZSwgd2hpY2ggaXMgc2hvd24gaW4gdGhlIHNhbWUgY29sb3IuIFNlZSBpZiB5b3UgY2FuIGlkZW50aWZ5IHRoZSBlbnp5bWUsIHdoaWNoIGlzIHRoZSB0aGluZyB0aGF0IGNoYW5nZWQgdGhlIHN1YnN0cmF0ZSBpbnRvIHRoZSBwcm9kdWN0cy4=

Cg==

[Qq]

[q] In the diagram below, the product of the reaction is represented by

[c]IDEgwqDCoA==[Qq][c]IDIgwqDCoA==[Qq][c]IDMgwqDCoA==[Qq][c]IDQgwqDCoA==[Qq][c]ID U=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSByZXByZXNlbnRzIHRoZSBlbnp5bWUuIFNlZSBpZiB5b3UgY2FuIGlkZW50aWZ5IHRoZSBwcm9kdWN0IHRoYXQgdGhlIGVuenltZSBjcmVhdGVzIGFmdGVyIGludGVyYWN0aW5nIHdpdGggdGhlIHN1YnN0cmF0ZSwgd2hpY2ggaXMgc2hvd24gYXQgbnVtYmVyIDMu[Qq]

[f]IE5vLiBOdW1iZXIgMiByZXByZXNlbnRzIHRoZSBhY3RpdmUgc2l0ZSwgd2hpY2ggaXMgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCBpdHMgc3Vic3RyYXRlLiBTZWUgaWYgeW91IGNhbiBpZGVudGlmeSB0aGUgcHJvZHVjdCB0aGF0IHRoZSBlbnp5bWUgY3JlYXRlcyBhZnRlciBpbnRlcmFjdGluZyB3aXRoIHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIHNob3duIGF0IG51bWJlciAzLg==[Qq]

[f]IE5vLiBOdW1iZXIgMyByZXByZXNlbnRzIHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIGFib3V0IHRvIGJpbmQgd2l0aCB0aGUgZW56eW1lLiBTZWUgaWYgeW91IGNhbiBpZGVudGlmeSB0aGUgcHJvZHVjdCBvZiB0aGUgcmVhY3Rpb24sIHdoaWNoIGlzIHNob3duIGluIHRoZSBzYW1lIGNvbG9yIGFzIHRoZSBzdWJzdHJhdGUsIGFuZCB3aGljaCBhcHBlYXJzIGF0IHRoZSBlbmQgb2YgdGhlIHJlYWN0aW9uLg==[Qq]

[f]IE5vLiBOdW1iZXIgNCByZXByZXNlbnRzIHRoZSBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgsIHdoaWNoIGluY2x1ZGVzIGJvdGggZW56eW1lIGFuZCBzdWJzdHJhdGUuIFRoaXMgY29tcGxleCBmb3JtcyBhcyB0aGUgdHdvIGFyZSB0ZW1wb3JhcmlseSBib25kZWQgdG9nZXRoZXIgYXMgdGhlIGVuenltZSBjYXRhbHl6ZXMgdGhlIHJlYWN0aW9uLiBTZWUgaWYgeW91IGNhbiBpZGVudGlmeSB0aGUgcHJvZHVjdCBvZiB0aGUgcmVhY3Rpb24sIHdoaWNoIGlzIHNob3duIGluIHRoZSBzYW1lIGNvbG9yIGFzIHRoZSBzdWJzdHJhdGUsIGFuZCB3aGljaCBhcHBlYXJzIGF0IHRoZSBlbmQgb2YgdGhlIHJlYWN0aW9uLg==[Qq]

[f]IEV4Y2VsbGVudC4=wqAgTnVtYmVyIDUgcmVwcmVzZW50cyB0aGUgcHJvZHVjdHMgb2YgdGhlIHJlYWN0aW9uLiBUaGUgcHJvZHVjdHMsIHlvdSBjYW4gc2VlLCB3ZXJlIGZvcm1lcmx5IHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIHNob3duIGluIHRoZSBzYW1lIGNvbG9yLg==

Cg==

[Qq]

[q] In the diagram below, the substrate of the reaction is represented by

[c]IDEgwqDCoA==[Qq][c]IDIgwqDCoA==[Qq][c]IDMgwq DCoA==[Qq][c]IDQgwqDCoA==[Qq][c]IDU=

Cg==[Qq]

[f]IE5vLiBOdW1iZXIgMSByZXByZXNlbnRzIHRoZSBlbnp5bWUuIFNlZSBpZiB5b3UgY2FuIGlkZW50aWZ5IHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIHdoYXQgdGhlIGVuenltZSBpbnRlcmFjdHMgd2l0aC4=[Qq]

[f]IE5vLiBOdW1iZXIgMiByZXByZXNlbnRzIHRoZSBhY3RpdmUgc2l0ZSwgd2hpY2ggaXMgd2hlcmUgdGhlIGVuenltZSB3aWxsIGJpbmQgd2l0aCBpdHMgc3Vic3RyYXRlLiBTZWUgaWYgeW91IGNhbiBpZGVudGlmeSB0aGUgc3Vic3RyYXRlLCB3aGljaCBpcyB3aGF0IHRoZSBlbnp5bWUgaW50ZXJhY3RzIHdpdGgu[Qq]

[f]IEV4Y2VsbGVudC4gTnVtYmVyIDMgcmVwcmVzZW50cyB0aGUgc3Vic3RyYXRlLCB3aGljaCBpcyBhYm91dCB0byBiaW5kIHdpdGggdGhlIGVuenltZS4=[Qq]

[f]IE5vLiBOdW1iZXIgNCByZXByZXNlbnRzIHRoZSBlbnp5bWUtc3Vic3RyYXRlIGNvbXBsZXgsIHdoaWNoIGluY2x1ZGVzIGJvdGggZW56eW1lIGFuZCBzdWJzdHJhdGUuIFNlZSBpZiB5b3UgY2FuIGlkZW50aWZ5IGp1c3QgdGhlIHN1YnN0cmF0ZSwgd2hpY2ggaXMgd2hhdCB0aGUgZW56eW1lIGludGVyYWN0cyB3aXRoLg==[Qq]

[f]IE5vLg==wqAgTnVtYmVyIDUgcmVwcmVzZW50cyB0aGUgcHJvZHVjdHMgb2YgdGhlIHJlYWN0aW9uLiBUaGUgcHJvZHVjdHMsIHlvdSBjYW4gc2VlLCB3ZXJlIGZvcm1lcmx5IHRoZSBzdWJzdHJhdGUsIHdoaWNoIGlzIHNob3duIGluIHRoZSBzYW1lIGNvbG9yLg==wqAgU2VlIGlmIHlvdSBjYW4gaWRlbnRpZnkganVzdCB0aGUgc3Vic3RyYXRlLCB3aGljaCBpcyB3aGF0IHRoZSBlbnp5bWUgaW50ZXJhY3RzIHdpdGgu

[Qq]

[q] What’s the name for the process where environmental changes (in temperature or pH, for example) cause an enzyme’s shape to change, destroying its function?

[c]IGRlY2F0YWx5emF0aW9u[Qq]

[c]IGRlZm9ybWF0aW9u[Qq]

[c]IGRlbmF0dX JhdGlvbg==[Qq]

[c]IGRlZW56eW1pZmljYXRpb24u[Qq]

[f]IE5vLiBZb3UgcHJvYmFibHkgcmVjb2duaXplZCDigJhjYXRhbHlzdOKAmSBpbiB0aGlzIGNob2ljZSwgYnV0IHRoYXQgaXMgbm90IHRoZSBhbnN3ZXIuIE5leHQgdGltZSB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24sIHRoaW5rIG9mIHRoZSBmYWN0IHRoYXQgZW52aXJvbm1lbnRhbCBmYWN0b3JzIGhhdmUgY2hhbmdlZCB0aGUgbmF0dXJlIG9mIHRoZSBlbnp5bWUuIE9uZSB3b3JkIGluIHRoZSBwcmV2aW91cyBzZW50ZW5jZSBlc3NlbnRpYWxseSB0ZWxscyB5b3UgdGhlIGFuc3dlci4=[Qq]

[f]IE5vLiBUaGUgZW52aXJvbm1lbnRhbCBjaGFuZ2VzIGhhdmUsIGluZGVlZCwgZGVmb3JtZWQgdGhlIGVuenltZSwgYnV0IHRoZXJl4oCZcyBhIGJldHRlciBhbmQgbW9yZSB3aWRlbHkgdXNlZCB0ZXJtLiBOZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLCB0aGluayBvZiB0aGUgZmFjdCB0aGF0IGVudmlyb25tZW50YWwgZmFjdG9ycyBoYXZlIGNoYW5nZWQgdGhlIG5hdHVyZSBvZiB0aGUgZW56eW1lLiBPbmUgd29yZCBpbiB0aGUgcHJldmlvdXMgc2VudGVuY2UgZXNzZW50aWFsbHkgdGVsbHMgeW91IHRoZSBhbnN3ZXIu[Qq]

[f]IEV4YWN0bHkuIENoYW5naW5nIGFuIGVuenltZeKAmXMgc2hhcGUgZGVzdHJveXMgaXRzIGFiaWxpdHkgdG8gY2F0YWx5emUgYSByZWFjdGlvbi4gVGhpcyBjaGFuZ2UgaXMgY2FsbGVkIGRlbmF0dXJhdGlvbi4gVGhlIHZlcmIgaXMg4oCYdG8gZGVuYXR1cmUu4oCZ[Qq]

[f]IE5vLiBZb3UgcHJvYmFibHkgcmVjb2duaXplZCDigJhlbnp5bWXigJkgaW4gdGhpcyBjaG9pY2UsIGJ1dCB0aGlzIGlzIG5vdCB0aGUgY29ycmVjdCB0ZXJtIChub3QgaXMgaXQgYSByZWFsIHdvcmQpLiBOZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLCB0aGluayBvZiB0aGUgZmFjdCB0aGF0IGVudmlyb25tZW50YWwgZmFjdG9ycyBoYXZlIGNoYW5nZWQgdGhlIG5hdHVyZSBvZiB0aGUgZW56eW1lLiBPbmUgd29yZCBpbiB0aGUgcHJldmlvdXMgc2VudGVuY2UgZXNzZW50aWFsbHkgdGVsbHMgeW91IHRoZSBhbnN3ZXIu

Cg==

[Qq]

[q] Enzymes have a pH optimum: a pH at which they’ll have maximum activity. In the diagram below, the optimum is shown at

[c]IDEgwqDCoA==[Qq][c]IDIgwq DCoA==[Qq][c]IDM=

Cg==[Qq]

[f]IE5vLiBUaGUgb3B0aW11bSBpcyB3aGVyZSB0aGUgZW56eW1l4oCZcyBhY3Rpdml0eSB3aWxsIGJlIHRoZSBoaWdoZXN0LiBFbnp5bWUgYWN0aXZpdHkgaXMgc2hvd24gb24gdGhlIFktYXhpcywgd2l0aCBoaWdoZXIgbWVhbmluZyBtb3JlIGFjdGl2aXR5LiBOZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLCBsb29rIGZvciB0aGUgaGlnaCBwb2ludCBvbiB0aGUgZ3JhcGgu[Qq]

[f]IE5pY2Ugam9iIS4gTnVtYmVyIDIgcmVwcmVzZW50cyB0aGUgZW56eW1l4oCZcyBwSCBvcHRpbXVtLCB0aGUgcEggd2hlcmUgdGhlIGVuenltZeKAmXMgYWN0aXZpdHkgd2lsbCBiZSBhdCBpdHMgaGlnaGVzdCByYXRlLg==[Qq]

[f]IE5vLiBUaGUgb3B0aW11bSBpcyB3aGVyZSB0aGUgZW56eW1l4oCZcyBhY3Rpdml0eSB3aWxsIGJlIHRoZSBoaWdoZXN0LiBFbnp5bWUgYWN0aXZpdHkgaXMgc2hvd24gb24gdGhlIFktYXhpcywgd2l0aCBoaWdoZXIgbWVhbmluZyBtb3JlIGFjdGl2aXR5LiBOZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLCBsb29rIGZvciB0aGUgaGlnaCBwb2ludCBvbiB0aGUgZ3JhcGgu

Cg==

[Qq]

[q] Enzymes have a pH optimum: a pH at which they’ll have maximum activity. In the diagram below, which number shows where the enzyme has lost its activity because of conditions that are too acidic?

[c]IDEgwq DCoA==[Qq][c]IDIgwqDCoA==[Qq][c]IDM=

Cg==[Qq]

[f]IEV4YWN0bHkuIE9uIHRoZSBwSCBzY2FsZSwgbG93ZXIgbWVhbnMgbW9yZSBhY2lkaWMuIEF0IHBvaW50IDEsIGFjdGl2aXR5IGlzIGxvdyAoc2hvd24gb24gdGhlIFktYXhpcykgYW5kIHRoZSBwSCBpcyBiZWxvdyB0aGUgb3B0aW11bSBwSCwgd2hpY2ggbWVhbnMgbW9yZSBhY2lkaWMgKGZhciB0byB0aGUgbGVmdCBvbiB0aGUgWC1heGlzKS4=[Qq]

[f]IE5vLiBOdW1iZXIgMiByZXByZXNlbnRzIHRoZSBlbnp5bWXigJlzIHBIIG9wdGltdW0sIHRoZSBwSCB3aGVyZSB0aGUgZW56eW1l4oCZcyBhY3Rpdml0eSB3aWxsIGJlIGF0IGl0cyBoaWdoZXN0IHJhdGUuwqAgTmV4dCB0aW1lLCBsb29rIGZvciBhIG51bWJlciB0aGF0IHNob3dzIGxvd2VyIGFjdGl2aXR5IChsb3dlciBvbiB0aGUgWS1heGlzKSwgYW5kIGxvd2VyIHBIICh0byB0aGUgbGVmdCBvbiB0aGUgWC1heGlzKS4=[Qq]

[f]IE5vLiBBdCBudW1iZXIgMyB0aGUgYWN0aXZpdHkgaXMgbG93IChhcyBzaG93biBieSB0aGUgcG9zaXRpb24gb24gdGhlIFktYXhpcyksIGJ1dCB0aGUgcG9zaXRpb24gb24gdGhlIFgtYXhpcyBpbmRpY2F0ZXMgYSBoaWdoZXIgcEgsIHdoaWNoIHdvdWxkIG1lYW4gbW9yZSBiYXNpYy4gTmV4dCB0aW1lLCBjaG9vc2UgYSBtb3JlIGFjaWRpYyBwb2ludCBvbiB0aGUgZ3JhcGggKGJ1dCB3aXRoIHRoZSBzYW1lIGxldmVsIG9mIGFjdGl2aXR5KS4=

Cg==

[Qq]

[q] In the diagram below, which number shows the optimum temperature for this enzyme?

[c]IDEgwqDCoA==[Qq][c]IDIgwq DCoA==[Qq][c]IDM=

Cg==[Qq]

[f]IEVuenltZSBhY3Rpdml0eSBpcyBzaG93biBvbiB0aGUgWS1heGlzLiBBdCBwb2ludCBudW1iZXIgMSwgZW56eW1lIGFjdGl2aXR5IGlzIHZlcnkgbG93LiBBdCB0aGUgb3B0aW11bSB0ZW1wZXJhdHVyZSwgdGhlIGFjdGl2aXR5IHdvdWxkIGJlIGhpZ2hlc3Qu[Qq]

[f]IEV4Y2VsbGVudDogdGhlIG9wdGltdW0gdGVtcGVyYXR1cmUgaXMgdGhlIG9uZSB3aGVyZSBhY3Rpdml0eSB3b3VsZCBiZSB0aGUgaGlnaGVzdCBvbiB0aGUgWSBheGlzLCBhcyBzaG93biBhdCBwb2ludCAyLg==[Qq]

[f]IEVuenltZSBhY3Rpdml0eSBpcyBzaG93biBvbiB0aGUgWS1heGlzLiBBdCBwb2ludCBudW1iZXIgMywgZW56eW1lIGFjdGl2aXR5IGlzIHZlcnkgbG93LiBBdCB0aGUgb3B0aW11bSB0ZW1wZXJhdHVyZSwgdGhlIGFjdGl2aXR5IHdvdWxkIGJlIGhpZ2hlc3Qu

Cg==

[Qq]

[q] In the diagram below, which number shows the point where denaturation has caused enzyme activity to fall.

[c]IDEgwqDCoA==[Qq][c]IDIgwqDCoA==[Qq][c]ID M=

Cg==[Qq]

[f]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[Qq]

[f]IE5vLiBFbnp5bWUgYWN0aXZpdHkgaXMgc2hvd24gb24gdGhlIFktYXhpcy4gQXQgcG9pbnQgbnVtYmVyIDIsIGFjdGl2aXR5IGlzIHZlcnkgaGlnaCwgd2hpY2ggbWVhbnMgdGhhdCB0aGUgZW56eW1lIGlzIHByb2JhYmx5IGluIGdvb2Qgc2hhcGUgKG5vdCBkZW5hdHVyZWQpLg==wqAgRGVuYXR1cmF0aW9uIHVzdWFsbHkgY29tZXMgYWJvdXQgYnkgZXhjZXNzaXZlIHRlbXBlcmF0dXJlLiBUaGluayBvZiB0aGF0IG5leHQgdGltZSB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24u[Qq]

[f]IEV4Y2VsbGVudC4gQXQgcG9pbnQgMywgdGhlIHRlbXBlcmF0dXJlIGlzIGhpZ2ggKGFzIHNob3duIG9uIHRoZSBYLWF4aXMpLCBhbmQgYWN0aXZpdHkgaXMgbG93IChhcyBzaG93biBvbiB0aGUgWS1heGlzKS4gRXhjZXNzaXZlIGhlYXQgY2FuIGNhdXNlIGVuenltZXMgdG8gZGVuYXR1cmUsIGRlc3Ryb3lpbmcgdGhlaXIgYWN0aXZpdHku

Cg==

[Qq]

[q] Which of the following environmental changes would be LEAST LIKELY to cause enzymes to denature.

[c]IHRvbyBtdWNoIH N1YnN0cmF0ZS4=[Qq]

[c]IHRvbyBtdWNoIGhlYXQ=[Qq]

[c]IHRvbyBtdWNoIHNhbHQu[Qq]

[c]IGEgcEggd2F5IGFib3ZlIHRoZSBvcHRpbXVtLg==[Qq]

[f]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[Qq]

[f]IE5vLiBIZWF0IGlzIGEgbWFqb3IgZmFjdG9yIGJlaGluZCBlbnp5bWUgZGVuYXR1cmF0aW9uLiBUaGUgcmVhc29uIHdoeSBpcyB0aGF0IGVuenltZXMgYXJlIHByb3RlaW5zLCBhbmQgcHJvdGVpbnMgaGF2ZSBhIDMtRCBzaGFwZSB0aGF04oCZcyBkZXRlcm1pbmVkLCBpbiBwYXJ0LCBieSB3ZWFrIGZvcmNlcyBsaWtlIGh5ZHJvZ2VuIGJvbmRzIHdoaWNoIGNhbiBlYXNpbHkgYmUgZGlzcnVwdGVkLiBUb28gbXVjaCBoZWF0IGNhbiBjaGFuZ2UgYW4gZW56eW1l4oCZcyBzaGFwZSwgZGVuYXR1cmluZyBpdC4gTmV4dCB0aW1lLCBjaG9vc2UgYW5vdGhlciBhbnN3ZXIu[Qq]

[f]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[Qq]

[f]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

Cg==

[Qq]

[q] Beano is a commercial enzyme product that claims to reduce flatulence (farting) by providing enzymes that break down certain carbohydrates that people sometimes have difficulty digesting. The product information tells you not to cook Beano with your food, but to ingest the enzyme tablets just before eating. Why can’t you cook Beano with your food?

[c]IFRoZSBlbnp5bWVzIGluIEJlYW5vLCBtaXhlZCB3aXRoIHlvdXIgZm9vZCwgd291bGQgYnJlYWsgYWxsIG9mIHRoZSBmb29kIGRvd24sIGxlYXZpbmcgeW91IHdpdGggYSBzb2dneSBtdXNoLg==[Qq]

[c]IFRoZSBlbnp5bWVzIGluIEJlYW5vIHRhc3RlIGhvcnJpYmxlIGFuZCB3b3VsZCBydWluIGFueSBkaXNoIHRoYXQgeW91IGNvb2tlZC4=[Qq]

[c]IEJlYW5vIG5lZWRzIGFuIGFjaWRpYyBlbnZpcm9ubWVudCBhbmQgbmVlZHMgdG8gZ2V0IGRvd24gdG8geW91ciBzdG9tYWNoIGJlZm9yZSB0aGUgZm9vZCBnZXRzIHRoZXJlLg==[Qq]

[c]wq AgQmVhbm8gY29udGFpbnMgZW56eW1lcy4gTGlrZSBtb3N0IGVuenltZXMsIGl0IHdpbGwgYmUgZGVuYXR1cmVkIGJ5IGhpZ2ggdGVtcGVyYXR1cmVzLiBUaGVyZWZvcmUgY29va2luZyB3b3VsZCBydWluIEJlYW5v4oCZcyBhY3Rpdml0eS4=[Qq]

[f]IE5vLiBUaGUgcHJvYmxlbSByZWxhdGVzIHRvIHRoZSBlZmZlY3QgdGhhdCBoZWF0IGhhcyBvbiBlbnp5bWVzLiBJZiB5b3UgY29va2VkIEJlYW5vIHdpdGggeW91ciBmb29kLCB5b3XigJlkIGJlIGV4cG9zaW5nIGl0IHRvIGZhaXJseSBleHRyZW1lIHRlbXBlcmF0dXJlcy4gS2VlcCB0aGF0IGluIG1pbmQgdGhlIG5leHQgdGltZSB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24u[Qq]

[f]IE5vLiB3aXRob3V0IGJlaW5nIHRvbyBwZXJzb25hbCwgSeKAmXZlIHRyaWVkIEJlYW5vIG15c2VsZi4gSXQgaGFzIGEgc2xpZ2h0bHkgc2FsdHkgdGFzdGUsIGEgYml0IHBvd2RlcnksIGJ1dCBub3RoaW5nIHRoYXQgd291bGQgcnVpbiBhIGRpc2guIFRoZSBwcm9ibGVtIHJlbGF0ZXMgdG8gdGhlIGVmZmVjdCB0aGF0IGhlYXQgaGFzIG9uIGVuenltZXMuIEtlZXAgdGhhdCBpbiBtaW5kIHRoZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==[Qq]

[f]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[Qq]

[f]IFRoYXTigJlzIGV4YWN0bHkgcmlnaHQuIElmIHlvdSBjb29rZWQgQmVhbm8sIHlvdeKAmWQgZGVuYXR1cmUgaXRzIGVuenltZXMsIG1ha2luZyBpdCBpbmVmZmVjdGl2ZSBhdCBoZWxwaW5nIHlvdSBicmVhayBkb3duIHRoZSBjYXJib2h5ZHJhdGVzIHRoYXQgY2F1c2UgZ2FzLg==

Cg==

[Qq]

[q] Which of the following diseases is NOT caused by an inherited enzyme deficiency (the body’s inability to produce an enzyme). Note that this might be a tough question without having watch the Enzymes! music video above. 

[c]IFRheS1TYWNocyBkaXNlYXNl[Qq]

[c]IFBoZW55bGtldG9udXJpYSAoUEtVIGRpc2Vhc2Up[Qq]

[c]IEdhbGFjdG9zZW1pYQ==[Qq]

[c]IFNpY2tsZS1jZW xsIEFuZW1pYQ==[Qq]

[f]IE5vLiBUYXktU2FjaHMgaXMgYW4gaW5oZXJpdGVkIGRpc29yZGVyIGludm9sdmluZyB0aGUgYm9keeKAmXMgaW5hYmlsaXR5IHRvIHByb2R1Y2UgYW4gZW56eW1lIGNhbGxlZCA=SGV4b3NhbWluaWRhc2UgQS4gV2l0aG91dCB0aGlzIGVuenltZSwgYSBmYXR0eSBzdWJzdGFuY2UgYnVpbGRzIHVwIGluIHRoZSBicmFpbiwgY2F1c2luZyBhIHZhcmlldHkgb2YgbmV1cm9sb2dpY2FsIHN5bXB0b21zLCBhbmQsIGV2ZW50dWFsbHksIGRlYXRoLiBOZXh0IHRpbWUsIGNob29zZSBhIGRpZmZlcmVudCBjb25kaXRpb24u[Qq]

[f]IE5vLiBQS1UgZGlzZWFzZSBpcyBjYXVzZWQgYnkgdGhlIGJvZHnigJlzIGluYWJpbGl0eSB0byBwcm9kdWNlIGFuIGVuenltZSB0aGF0IGJyZWFrcyBkb3duIHRoZSBhbWlubyBhY2lkIHBoZW55bGFsYW5pbmUsIHdoaWNoIGNvbnNlcXVlbnRseSBjYW4gYWNjdW11bGF0ZSB0byB0b3hpYyBsZXZlbHMuIFRoZSBkaXNlYXNlIGNhbiBiZSB0cmVhdGVkIHRocm91Z2ggYSBkaWV0IHRoYXQgcmVtb3ZlcyB0aGUgZW56eW1lJiM4MjE3O3Mgc3Vic3RyYXRlIOKAkyBwaGVueWxhbGFuaW5lLiA=TmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgY29uZGl0aW9uLiA=[Qq]

[f]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Y2hvb3NlIGEgZGlmZmVyZW50IGNvbmRpdGlvbi4g[Qq]

[f]IENvcnJlY3QuIFNpY2tsZSBjZWxsIGFuZW1pYSBpcyBhbiBpbmhlcml0ZWQgZGlzZWFzZSBjYXVzZWQgYnkgYSBtdXRhdGlvbiBpbiB0aGUgZ2VuZSBmb3IgaGVtb2dsb2Jpbi4gV2hpbGUgaGVtb2dsb2JpbiBpcyBhIHByb3RlaW4sIGl0IGlzIG5vdCBhbiBlbnp5bWUu[Qq]

[q]The energy required to get a chemical reaction started is known as [hangman] energy.

[c]YWN0aXZhdGlvbg==[Qq]

[q]The substance an enzyme acts upon is called the [hangman].

[c]c3Vic3RyYXRl[Qq]

[q]The specific area on an enzyme where it binds with its substrate is called its [hangman] [hangman].

[c]YWN0aXZl[Qq]

[c]c2l0ZQ==[Qq]

[q]At the moment when an enzyme binds with its substrate at the active site, it forms an [hangman]-[hangman] complex.

[c]ZW56eW1l[Qq]

[c]c3Vic3RyYXRl[Qq]

[q]A useful metaphor about the specificity of enzymes states that a substrate usually has only one enzyme that it can interact with. This is called the [hangman] and [hangman] model of enzyme action.

[c]bG9jaw==[Qq]

[c]a2V5[Qq]

[q]The idea that in an enzyme-substrate complex, an enzyme will bend in a way that stresses the bonds of the substrate is called the [hangman]-[hangman] model of enzyme action.

[c]aW5kdWNlZA==[Qq]

[c]Zml0[Qq]

[q]Every enzyme has a pH or temperature [hangman] at which it functions best.

[c]b3B0aW11bQ==[Qq]

[q]When heat, pH changes, or other factors in an enzyme’s environment cause it to change shape, the enzyme loses its ability to function. At that point, the enzyme is said to be [hangman].

[c]ZGVuYXR1cmVk[Qq]

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