Biochem 23: TCA cycle

Question 1

Substrate of TCA cycle

Answer 1

Acetyl CoA

Question 2

a-Ketoglutarate decarboxylation is catalysed by

Answer 2

a-ketoglutarate dehydrogenase complex

Question 3

Acetyl CoA yields

Answer 3

2 CO2

NADH

FAD2H

GTP

Question 4

What enzyme catalyses oxydation of pyruvate to Acetyl CoA

Answer 4

Pyruvate dehydrogenase complex PDC

Question 5

Inhibtion of pyruvate oxydation in TCA cycle leads to

Answer 5

Pyruvate reduction to lactate

Question 6

Electron transport chain basic concept

Answer 6

NADH and FAD2H from TCA cycle drives electrons to O2 which creates gradient used to drive ATP synthesis

Question 7

Riboflavin turned into ____

how

Answer 7

FAD

Riboflavin gets phosphate from flavokinase to make FMN (flavin mononucleotide)

FMN gets AMP from FAD synthase to make FAD

Question 8

Thiamin deficiency in alcoholism due to

Answer 8

Poor absorbtion

Question 9

TCA cycle thermal efficiency

Answer 9

90%

Question 10

Pyruvate dehydrogenase complex defficiency

Answer 10

Pyruvate accummulates and ATP drops. Low atp leads to anerobic glycolysis, leading to lactic acidosis

Question 11

Most common form of PyruvateDehydrogenaseComplex genetic defects

Answer 11

Is X-linked dominant. alpha subunit of E1 is defective

Question 12

Increased NADH/NAD+ ratio inhibits

Answer 12

pyruvate dehydrogenase

Question 13

Beriberi is primarily a

Answer 13

Thiamine defficiency

Question 14

What acid accumulates in thiamin defficiency

Answer 14

Pyruvic acid

Question 15

Succinate dehydrogenase is embeded in

Answer 15

Inner mitochondrial membrane

Question 16

NADH+/NAD ratio during excecise

Answer 16

Is decreased

Question 17

Electron donor in TCA cycle

Answer 17

Acetyl CoA

Question 18

Pyruvate carboxylase deficiency

Answer 18

Pyruvate cannot be converted to oxoacelate thereby reducing TCA cycle.

This leads to Acetyl CoA buildup which inhibitds PDC

Lactic acid pathway proceeds leading to lactic acidosis

Question 19

Vitamine precursor of coenzyme A

Answer 19

Panthothenate

Question 20

PDC is inhibitted by

Answer 20

PDC kinase