Lecture 10.20.14 (Exam #3)

Question 1

What are the 2 concepts of glycolysis?

Answer 1

1. preparatory stage: energy consumption phase (use ATP)

2. energy output phase (ATP made)

Question 2

Enzyme used in Step 1 of glycolysis?

Answer 2

hexokinase

Question 3

Characteristics of Hexokinase

Answer 3

big conformational change when substrate bound
G6P can act as product inhibitor
ATP allosteric effector

Question 4

ATP _______ hexokinase

Answer 4

slow (T)

Question 5

ADP/AMP _______ hexokinase

Answer 5

go (R)

Question 6

In a reversible reaction….

Answer 6

the energy of the products and reactants are about the same; the concentration determines the direction

Question 7

In an irreversible reaction….

Answer 7

products are more favored/ stable

exothermic reaction

Question 8

How many metabolically irreversible reactions are in glycolysis?

Answer 8

3

Question 9

Hexokinase (2)

Answer 9

converts glucose to G6P

use ATP

Question 10

Enzyme used in Step 2 of glycolysis?

Answer 10

phosphoglucose isomerase

Question 11

Phosphoglucose isomerase (PGI) (2)

Answer 11

converts G6P to F6P

important for step 4

Question 12

Enzyme used in Step 3 of glycolysis?

Answer 12

phosphofructose kinase (PFK)

Question 13

Phosphofructose Kinase (PFK 1) (3)

Answer 13

converts F6P to F16BP

use ATP

Question 14

PFK 1 is a ______ step and ______ _____ step

Answer 14

committing step/ rate limiting

Question 15

Where does ATP bind to trap enzyme in T state?

Answer 15

regulatory site

Question 16

Where can ATP bind?

Answer 16

active site (small Km) or regulatory site (big Km)

Question 17

What happens when the pH decreases?

Answer 17

ATP is more sensitive to regulatory region

Question 18

PFK2

Answer 18

converts F6P to F26BP

Question 19

Fructose Bisphosphate

Answer 19

converts F26BP to F6P

Question 20

When is PFK1 able to work?

Answer 20

when F26BP is bound to the regulatory site

Question 21

Enzyme used in Step 4 of glycolysis?

Answer 21

aldolase

Question 22

Aldolase

Answer 22

converts F16BP to GAP and DHAP

Question 23

Carbons in DHAP and GAP?

Answer 23

C3-4 are C1 & 2 of DHAP and GAP (add carbons)

Question 24

Enzyme used in Step 5 of glycolysis?

Answer 24

TIM or TPI

Question 25

TIM

Answer 25

converts DHAP to GAP (vice versa)

catalytically perfect

Question 26

TIM prefers to turn ______ to _____

Answer 26

GAP to DHAP

Question 27

TIM: Glutamic Acid acts as a___ while His acts as a _____

Answer 27

base; acid