Metabolism - Energy Storage

Question 1

What is an allosteric activator of muscle glycogen phosphorylase, but not of the liver form?

Answer 1

AMP

Question 2

What is the rate limiting enzyme for glycogen degradation?

Answer 2

Glycogen phosphorylase

And debranching enzyme

Question 3

What is the rate limiting enzyme for glycogen synthesis?

Answer 3

Glycogen synthase

Question 4

What enzyme, involved in glycogen breakdown for glucose production, is not present in muscle?

Answer 4

Glucose 6 phosphatase

Question 5

Where does gluconeogenesis occur?

Answer 5

Liver

Also in kidney to a lesser extent

Question 6

What are the 3 major precurors to gluconeogenesis?

Answer 6

Lactate

Glycerol

Amino Acids

Question 7

Under what conditions and where is lactate produced?

Answer 7

Anaerobic glycolysis

RBCs and exercising muscle

Question 8

Which amino acid is mainly involved in gluconeogenesis?

Answer 8

Alanine

Question 9

What cycle is considered in lactate precursor use for gluconeogenesis?

Answer 9

Cori cycle

Question 10

Where is PEPCK found?

Answer 10

Mitochondria

Question 11

What enzyme converts pyruvate to oxaloacetate?

Answer 11

Pyruvate carboxylase

Question 12

What is required for PEPCK’s conversion reaction?

Answer 12

GTP

Question 13

What reaction does PEPCK catalyse?

Answer 13

Oxaloacetate > Phosphoenolpyruvate

Question 14

What are the key enzymes involved in gluconeogenesis?

Answer 14

PEPCK
Fructose-1,6-Bisphosphatase
Glucose 6 phosphatase

Question 15

What enzyme acts opposite to phosphofructokinase?

Answer 15

Fructose-1,6-Bisphosphatase

Question 16

What amino acids are both glucogenic and ketogenic?

Answer 16

Phenylalanine
Isoleucine
Tryptophan
Tyrosine
Threonine

Question 17

What is glucagon’s affect on muscle glycogen?

1. Increases glycogen synthesis. 2. Increases glycogen breakdown. 3. No effect

Answer 17

No effect.