Lecture 21 & 25 - Nuc & Glyc Regulation Flashcards Preview

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Flashcards in Lecture 21 & 25 - Nuc & Glyc Regulation Deck (17)
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1
Q

What compound negatively regulates adenylosuccinate reductase?

A

AMP

2
Q

What regulates IMP dehydrogenase?

A

(-) GMP

3
Q

PRPP synthetase is regulated by what compounds?

A

(+) Pi

-) GMP, IMP, AMP (purine nucleotides

4
Q

A deficiency in nucleotide reductase would result in:
A. Greater [RNA]
B. Lesser [RNA]
C. Greater [DNA]

A

A. Greater [RNA]

5
Q

Fumerate is an intermediate of _____ & may funnel into ____.

A

Purine synthesis; TCA Cycle

6
Q

Production of carbamoyl-phosphate is regulated how?

A

(+) PRPP

(-) UTP

7
Q

PRPP —> _______ via enzyme ________ is the committed step of purine synthesis.

A

Phosphribosylamine; glutamine phosphoribosyl pyrophosphate amidotransferase

8
Q

Irreversible reactions of glycolysis:
A. Hexokinase, phosphfructokinase, pyruvate kinase
B. Hexokinase, phosphofructokinase, G-3-P dehydrogenase
C. Hexokinase, enolase, pyrivate kinase

A

A. Hexokinase, phosphofructokinase, pyruvate kinase

9
Q

Which stage of glycolysis is known as the “committed step?
A. Stage 3
B. Stage 2
C. Stage 1

A

C. Stage 1

10
Q

(-) regulator of hexokinase

A

Glucose-6-P (product of reaction)

11
Q

(-) regulator of liver glucokinase

A

Glucagon, F-6-P (fructose can enter into glycolysis in the liver)

12
Q

(+) regulator of glucokinase

A

Glucose, fructose 1-P (substrate of glucokinase in the liver), insulin

13
Q

(-) regulator of phosphofructokinase

A

ATP

Citrate

14
Q

(+) regulator of phosphofructokinase

A

AMP

Fructose-2,6-BP (downstream product of this enyzme’s product)

15
Q

What does elevated [citrate] indicate to phosphofrucokinase?

A

A presence of many carbon skeletons available for use

16
Q
High [BGL] produces a dephosphorylation of \_\_\_\_\_, which increases pyruvate/ATP production.
A. Enolase
B. Phosphofructokinase
C. Pyruvate kinase
D. Triose phosphate isomerase
A

C. Pyruvate kinase

17
Q

Describe the changes to the dual-domain enzyme phosphofructokinase.

A

The PFK portion is a kinase. When blood glucose is high, ADP is phosphorylated to form ATP. This increases release of glucose from glycogen.

The FBPase is a phosphatase. With decreased blood glucose levels, ATP is dephosphorylated. This phosphorylation of ADP comes from the removal of the Pi from FBPase. This dephosphorylation produces greater gluconeogenesis.