Glycolysis

Question 1

What are the 3 rate limiting/regulatory enzymes in glycolysis

Answer 1

Hexokinase, PFK, Pyruvate kinase

Question 2

Where does the Krebs cycle occur?

Answer 2

Mitochondria

Question 3

Where does glycolysis occur

Answer 3

Cytosol of the cell

Question 4

What must be present for the Krebs cycle to occur?

Answer 4

Oxygen

Question 5

Which portion of the Krebs cycle is irreversible?

Answer 5

The oxidation of pyruvate into acetyl CoA

Question 6

Allosteric inhibitors of pyruvate dehydrogenase

Answer 6

1. High [acetyl CoA]
2. High [NADH]
3. High [ATP]
4. low [pyruvate]

Question 7

Allosteric activators of pyruvate dehydrogenase

Answer 7

1. high [ca2+]
2. high [pyruvate]
3. low levels of ATP
4. low levels of NADH

Question 8

First rate limiting step in the Krebs cycle

Answer 8

Activation or deactivation of pyruvate dehydrogenase

Question 9

Net number of ATP produced during glycolysis

Answer 9

2

Question 10

Rate limiting steps in the Krebs cycle

Answer 10

citrate synthase, isocitrate dehydrogenase, alpha KG dehydrogenase

Question 11

Glucose regulating hormones

Answer 11

Insulin, Glucagon, EPI/NE

Question 12

GLUT 1

Answer 12

Protein that facilitates transport of glucose to the RBC, brain and placenta

Question 13

GLUT 4

Answer 13

Protein that facilitates transport of glucose to the skeletal muscle (has a low affinity for glucose so A LOT of glucose is needed to activate)

Question 14

GLUT 3

Answer 14

Protein that facilitates glucose transport to the brain (High affinity for glucose, very little glucose is needed to activate transport)

Question 15

GLUT 4

Answer 15

Facilitates transport of glucose to skeletal muscle and adipose tissue

Question 16

3 ways to activate GLUT 4

Answer 16

1. Exercise
2. Insulin
3. Hypoxia

Question 17

CAMK

Answer 17

enzyme that initiates the movement of GLUT4 to plasma membrane to bring in exogenous glucose

Question 18

6 things that regulate glucose uptake

Answer 18

1. Blood flow
2. [glucose]
3. [glycogen]
4. Exercise
5. [Hormone] - insulin, glucagon, cortisol, EPI/NE
6. Exercise

Question 19

Points of regulation in the Krebs cycle

Answer 19

1. PDH (pyruvate dehydrogenase)
2. Isocitrate dehydrogenase
3. [OAA]

Question 20

Isocitrate Dehydrogenase is regulated by

Answer 20

Levels of NADH
High levels of NADH will slow down the action of isocitrate dehydrogenase

Question 21

Gluconeogenesis

Answer 21

Glucose production

Question 22

Regulation of Gluconeogenesis

Answer 22

1. Fasting/Starving
2. Deactivation of Pyruvate Dehydrogenase
3. Activation of Pyruvate Carboxylase
4. Activation of Malate Dehydrogenase
5. Deactivation of Isocitrate dehydrogenase (slow down the Krebs cycle)
6. High [ATP} necessary

Question 23

What part of the cell does Gluconeogenesis occur?

Answer 23

Cytosol