DSA 3: Fundamentals of Biochemical Reactions

Question 1

What is the free energy equation?

Answer 1

ΔG = ΔG°΄ + RTln(Products / Reactants)

Question 2

When the body’s pH is low, what does it do?

Answer 2

Eliminate H+ and reabsorb HCO3-

Question 3

When the body’s pH is high, what does it do?

Answer 3

Fewer H+ is eliminated and less HCO3- is reabsorbed

Question 4

What is going on in respiratory acidosis?

Answer 4

Increase of CO2 due to hypoventilation.

This causes equilibrium to shift to left

Question 5

What is going on in metabolic acidosis?

Answer 5

Strong acid present

This causes equilibrium to shift to left

Question 6

What is going on in respiratory alkalosis?

Answer 6

Decrease of CO2 due to hyperventilation.

This causes equilibrium to shift to right

Question 7

What is going on in metabolic alkalosis?

Answer 7

Strong base present

This causes equilibrium to shift to right

Question 8

How do catalysts function in reactions?

Answer 8

They lower activation energy and increase reaction rate.

NO affect on ΔG

Question 9

What are oxidoreductases?

Answer 9

Enzymes that transfer electrons from donor to acceptor

LEO GER (Lose electron - oxidized. Gain electron - reduced)

Question 10

What are transferases?

Answer 10

Enzymes that transfer functional groups between molecules

Question 11

What are isomerases?

Answer 11

Rearrange/isomerize molecules

Question 12

What are lyases?

Answer 12

Add/remove atoms to form DOUBLE BONDS

Question 13

What are ligases?

Answer 13

Bonds formed via hydrolysis of ATP

Question 14

What are hydrolases?

Answer 14

Bonds are cleaved via addition of water

Question 15

What is difference between cofactors and coenzymes?

Answer 15

Cofactors: metal ions
Coenzymes: organic molecules derived from vitamins

Question 16

___ and ___ affect optimal enzyme activity.

Answer 16

Temperature and pH

Question 17

What is Vmax?

Answer 17

Saturation of enzymes (max turnover)

Question 18

What does it mean when Km is low and high?

Answer 18

High Km: low affinity for E-S complex

Low Km: high affinity for E-S complex

Question 19

What is competitive inhibition? How does Km and Vmax change?

Answer 19

Inhibitor binds to enzyme at substrate binding site.

No change for Vmax
Increase in Km

Question 20

What is noncompetitive inhibition? How does Km and Vmax change?

Answer 20

Inhibitor binds to enzyme and enzyme/substrate

Decrease for Vmax
No change in Km

Question 21

What is unncompetitive inhibition? How does Km and Vmax change?

Answer 21

Inhibitor binds to enzyme/substrate complex only

Decrease for Vmax
Decrease in Km

Question 22

What are allosteric enzymes?

Answer 22

They bind noncovalently to enzyme (not at catalytic site) and can have positive or negative affects.

They induce conformational changes to either enhance or inhibit substrate binding

Question 23

What are isozymes?

Answer 23

They have same function but different properties and binding sites.