Lecture 9 - Pyruvate Metabolism Flashcards Preview

Fuel Metabolism - 2016 > Lecture 9 - Pyruvate Metabolism > Flashcards

Flashcards in Lecture 9 - Pyruvate Metabolism Deck (21):
1

Anaerobic glycolysis produces lactate as the end product of glycolysis. In what two locations of the body does this occur?

1. Skeletal muscle
2. Red blood cells

2

The pyruvate dehydrogenase complex (PDH) links glycolysis to what two processes?

1. TCA cycle
2. Fatty acid synthesis

3

Pyruvate dehydrogenase complex is localized in what part of the cell?

The mitochondrial matrix

4

Pyruvate dehydrogenase complex is subject to regulation by its products. Which two products (of the reaction catalyzed by PDH) inhibit PDH?

1. Acetyl CoA
2. NADH

5

How does PDH kinase act on PDH? What effect does this have?

PDH kinase PHOSPHORYLATES PDH.
This inactivates the PDH enzyme.

6

PDH phosphatase is activated by what two molecules?

1. Insulin
2. Ca2+ in muscle (especially upon contraction)

7

Lactate is a substrate for gluconeogenesis by what organ?

Liver

8

Pyruvate carboxylase is localized in the mitochondrial matrix and catalyzes the reaction from pyruvate --> ________.

oxaloacetate

9

Oxaloacetate is the first intermediate in the pathway of _________.

gluconeogenesis

10

___________ is an allosteric ACTIVATOR of pyruvate carboxylase.

Acetyl CoA

11

Acetyl CoA is an allosteric ________ of pyruvate dehydrogenase.

inhibitor

12

A defect in either of the major pathways of pyruvate utilization - conversion to acetyl-CoA or to oxaloacetate - usually leads to an accumulation of what two substrates?

1. Lactate
2. Alanine

13

______ is a deficiency in thiamine because polished rice is consumed instead of unpolished rice.

Beri beri

14

____________ converts pyruvate to Acetyl-CoA.

A. Lactate dehydrogenase
B. Alanine aminotransferase
C. Pyruvate dehydrogenase complex
D. Pyruvate carboxylase

C - this occurs in the mitochondrial matrix

15

________ converts pyruvate to oxaloacetate.

A. Lactate dehydrogenase
B. Alanine aminotransferase
C. Pyruvate dehydrogenase complex
D. Pyruvate carboxylase

D - this occurs in the mitochondrial matrix

16

Acetyl CoA is an allosteric activator of ____________.

A. Lactate dehydrogenase
B. Alanine aminotransferase
C. Pyruvate dehydrogenase complex
D. Pyruvate carboxylase

D

17

Acetyl CoA is an allosteric inhibitor of _____________.

A. Lactate dehydrogenase
B. Alanine aminotransferase
C. Pyruvate dehydrogenase complex
D. Pyruvate carboxylase

C

18

In the fed state in the liver, pyruvate (from glucose) is converted to ________, which drives both the TCA cycle and FA synthesis.

acetyl CoA.

19

In the fasted state in the liver, pyruvate will be converted to ____________ to run gluconeogenesis.

Oxaloacetate

20

In the fed state in the skeletal muscle, pyruvate will be channeled into the _________ to make energy.

TCA cycle

21

In the fasted state in the skeletal muscle, there is not much glucose to make energy. ______ are converted to acetyl-CoA to make energy via the TCA cycle.

Fatty acids