Enzyme Function

Question 1

What is a metabolic pathway?

Answer 1

A series of steps beginning with a molecule

Question 2

Advantages of multi-step pathways

Answer 2

Multiple points to control how fast the reactions occur

Ability to divert pathway intermediates to other pathways to do other things

Changes metabolism

Question 2

Anabolic pathways

Answer 2

Consume energy to build complex molecules from simpler compounds

Question 3

Catabolic pathways

Answer 3

Release energy by breaking down complex molecules

Question 4

1st law of thermodynamics

Answer 4

Energy cannot be created or destroyed

Question 5

2nd law of thermodynamics

Answer 5

Entropy increases in isolated systems

Question 6

Increase in entropy can cause a process to proceed_______?

Answer 6

Spontaneously

Question 7

When reactants have more free energy than the products_____.

Answer 7

Delta G is less than 0

Reaction is exergonic

Question 8

When reactants have less free energy than the products____?

Answer 8

Delta G is greater than 0

Reaction is endergonic

Question 9

What type of work does a cell do?

Answer 9

1. Chemical work
2. Transport work
3. Mechanical work

Question 10

Energy coupling drives cell processes by____?

Answer 10

Using energy from an exergonic reaction to drive an endergonic reaction

Question 11

Are enzymes catalysts? If yes, what do they do?

Answer 11

Yes. They speed up reactions by lowering activation energy without being consumed themselves or the overall delta G

Question 12

The reactant molecule is the enzymes______. When the enzyme binds to the ________ it becomes an __________.

Answer 12

Substrate

Substrate

Enzyme-substrate complex

Question 13

Induced fit model

Answer 13

Suggests that the active site and substrate are not perfect matches initially. The substrate induces a change in the shape of the enzyme. (shaking hands)

Question 13

What are co-factors? What is a coenzyme?

Answer 13

Non-protein helpers that initiate catalysis

An organic molecule

Question 14

What does enzyme shape dictate?

Answer 14

Function

Question 15

What does temperature do to an enzyme?

Answer 15

Speed up the reaction until it denatures

Question 16

Does pH denature proteins?

Answer 16

Yes

Question 17

What is substrate inhibation

Answer 17

A competitive inhibitor molecule resembles the substrate and binds to the active site

Question 18

What is feedback inhibation?

Answer 18

The inhibitor molecule binds elsewhere on the enzyme, changing the enzyme shape so the active site cannot bind with the substrate

Question 19

Allosteric regulation occurs in what kind of structures?

Answer 19

Quaternary structures where each subunit has an active site