Enzymes

Question 1

Enzymes are classified as which type of polymer?

Answer 1

Proteins.

Question 2

Enzymes are formed from chains of this monomer:

Answer 2

Amino acids.

Question 3

The general function of enzymes are to serve as:

Answer 3

Biological catalysts.

Question 4

What does it mean when something is an organic catalyst?

Answer 4

It speeds up the rate of a reaction by lowering the activation energy.

The activation energy is the energy needed for reactants to chemically react.

Question 5

Enzymes may work on ________ reaction at a time, but may be used ________ times.

Answer 5

Enzymes may work on one reaction at a time, but may be used many times.

Question 6

The lock and key aspect of enzymes means:

Answer 6

Enzymes are specific and will only work with particular substrates.

Question 7

Where does the substrate bind with the enzyme?

Answer 7

The activation site.

Question 8

An enzyme-catalyzed reaction saves ________ and __________.

Answer 8

An enzyme-catalyzed reaction saves time and energy.

Question 9

What does it mean for enzymes to have an induced fit model?

Answer 9

It means that the active site changes in shape slightly to best fit the substrate.

Question 10

True or False: Once the enzyme has changed shape slightly due to the induced fit model, it cannot return to its original state.

Answer 10

False.

Question 11

Metabolism is. . .

Answer 11

. . . the sum of all reactions that occur in a cell.

Question 12

A reaction during which we start out with a polymer and the products are monomers is:

Answer 12

A degradative reaction (hydrolysis).

Question 13

A reaction during which we start out with monomers and the product is a polymer is:

Answer 13

A synthetic reaction (dehydration synthesis).

Question 14

List the four factors that affect the rate of enzyme activity:

Answer 14

Substrate concentration, pH, temperature and enzyme concentration.

Question 15

Enzyme activity ________ as substrate concentration increases, until all active sites are filled and enzyme activity will _____________.

Answer 15

Enzyme activity increases as substrate concentration increases, until all active sites are filled and enzyme activity will level off.

Question 16

Enzyme activity ________ as temperature increases, until the temperature becomes high enough that enzyme activity will ________ because ___________.

Answer 16

Enzyme activity increases as temperature increases, until the temperature becomes high enough that enzyme activity will cease because the enzymes have denatured.

Question 17

Why do higher temperatures increase enzyme activity?

Answer 17

Because the substrates and enzymes move faster, will collide and lead to faster reactions.

Question 18

Optimal pH for an enzyme is:

Answer 18

The pH at which the rate of reaction is highest.

Question 19

Change in pH may affect an enzyme’s. . .

Answer 19

. . . ability to bond by denaturing the enzyme.

Question 20

True or false: Once an enzyme is denatured by a change in pH, it cannot return to its original form.

Answer 20

False.

If the enzyme is returned to its optimal pH, it will return to its native form.

Question 21

True or false: Once an enzyme has been denatured by exposure to extreme heat, it cannot return to its original state.

Answer 21

True.

Question 22

These molecules sit in the active site to aid in the bonding of an enzyme and a substate.

Answer 22

Cofactors and coenzymes.

Question 23

Cofactors are:

Answer 23

Ions.

Question 24

Coenzymes are:

Answer 24

Organic.

Question 25

This molecule sits in the active site and blocks the substrate from bonding with the enzyme.

Answer 25

A competitive inhibitor.

Question 26

This molecule sits on the allosteric site and causes the enzyme to change shape slightly.

Answer 26

A non-competitive inhibitor.

Question 27

The role of an inhibitor is to:

Answer 27

Restrict enzyme activity, which may limit the amount of a particular substrate’s production.

Question 28

Enzyme concentration is controlled by:

Answer 28

Genetic activation.

Question 29

An enzyme pathway is:

Answer 29

Like an assembly line, where the product of one enzyme becomes the substrate of the next.

Question 30

Feedback inhibition is:

Answer 30

Wherein the product of an enzymatic pathway suppresses the activity of those enzymes involved in the product’s creation.