TCA cycle

Question 1

The pyruvate dehydrogenase complex converts pyruvate into

Answer 1

Acetyl CoA

Question 2

the PDC requires cofactors to operate. What are they

Answer 2

Lipoic acid
Thiamin
CoA
Niacin
Riboflavin

Question 3

The PDC requires 3 steps to convert pyruvate to acetyl CoA. What are they?

Answer 3

Decarboxylation
Oxidation
Transfer of acetyl group to CoA
Regeneration of active enzyme

Question 4

The PDC is a __ subunit enzyme complex

Answer 4

3

Question 5

In E1 of the PDC, which Reaction is catalyzed

Answer 5

Decarboxylation of pyruvate

Question 6

In E2 of the PDC, which reaction is catalyzed

Answer 6

Transfer of acetyl group to CoA

Question 7

In E3 of the PDC, what is catalyzed

Answer 7

Regeneration of Disulfide form of lipoate

Question 8

PDH is active when it is________and inactive when__________

Answer 8

Dephosphorolated

Phosphorylated

Question 9

PDH is regulated by which enzymes

Answer 9

PDH kinase

PDH phosphotase

Question 10

PDH kinase is activated by

Answer 10

High ATP & acetyl CoA and NADH

Question 11

PDC phosphotase is activated when

Answer 11

ATP and acetylene CoA is low

Question 12

PDHC deficiency causes_________

Answer 12

Lactate buildup

Question 13

Arsenic poisoning inhibits______resulting in impaired production of acetylene CoA and energy production via oxidative phosphorylation

Answer 13

A subunit of PDHC

Question 14

Fatty acid oxidation inhibits PDCH because fatty acid oxidation forms a large amount of _________which would replace the amount formed in PDCH

Answer 14

Acetyl CoA (which already inhibits the complex)

Question 15

In the first step of the TCA cycle, acetyl CoA binds with oxaloacetate to form________via_________

Answer 15

Citrate; citrate synthase

Question 16

Citrate synthase requires ATP. T/F

Answer 16

False. Only a water molecule is needed

Question 17

Citrate synthase is highly regulated. T/F

Answer 17

True

Question 18

Citrate is isomerized to isocitrate via the enzyme

Answer 18

Aconitase

Question 19

Isocitrate is dehydrogenated to alpha-ketoglutarate via the enzyme

Answer 19

Isocitrate dehydrogenase

Question 20

The key regulatory enzymes of the TCA cycle is

Answer 20

Citrate synthase

Isocitrate dehydrogenase

Question 21

Isocitrate is dehydrogenated to form________in the TCA cycle

Answer 21

Alpha-ketogluterate

Question 22

This enzyme complex is similar to the PDHC which requires the same cofactors and has the same subunits

Answer 22

Alpha-ketoglutarate dehydrogenase complex

Question 23

Alpha-ketoglutarate is formed into succinyl CoA via

Answer 23

Alpha-ketoglutarate dehydrogenase complex

Question 24

Succinyl CoA is catalyzed by succinyl CoA synthetase to form __________and the cleavage of the CoA produces

Answer 24

Succinate;ATP/GTP

Question 25

Succinate is catalyzed by succinate dehydrogenase to form

Answer 25

Fumarate

Question 26

This is the only enzyme that is free floating and has physical contact with the ETC

Answer 26

Succinate dehydrogenase

Question 27

Fumerate is converted into_________ via fumerase and water

Answer 27

Malate

Question 28

Malate is catalyzed by malate dehydrogenase to for,

Answer 28

Oxaloacetate

Question 29

This reaction in the TCA cycle is considered unfavourable

Answer 29

Malate ———->oxaloacetate

Question 30

This reaction in the TCA cycle forms FADH2 from FAD+

Answer 30

Succinate to fumarate

Question 31

CO2 leaves the cycle during these 2 reactions

Answer 31

Isocitrate to alpha ketoglutarate Alpha ketoglutarate to succinyl,CoA

Question 32

3 NADH are formed via these reactions in the TCA cycle

Answer 32

Isocitrate to alpha ketoglutarate Alpha ketoglutarate to succinyl CoA Malate to oxaloacetate

Question 33

FADH2 is formed during this reaction

Answer 33

Succinate to fumarate

Question 34

PDHC is slowed down by these substrates

Answer 34

ATP Acetyl Coa\A Fatty acids NADH

Question 35

Formation of acetyl CoA from pyruvate is accelerated by these substrates

Answer 35

AMP CoA NAD+ Ca 2+

Question 36

Sythesis of citrate is inhibited by

Answer 36

NADH Succinyl CoA Citrate ATP

Question 37

Anaplerotic reactions are reactions which replenish intermediates in the TCA cycle. Pyruvate and PEP (Phosphoenol pyruvate) can be carboxylated to form

Answer 37

Oxaloacetate

Question 38

Anaplerotic reactions are reactions which replenish intermediates in the TCA cycle. Pyruvate with the prescence of a malic enzyme can be formed into

Answer 38

Malate

Question 39

Anaplerotic reactions are reactions which replenish intermediates in the TCA cycle. Glutamate can be formed into

Answer 39

Alpha ketoglutarate

Question 40

Pyruvate carboxylase can convert pyruvate to oxaloacetate with______as a cofactor

Answer 40

Biotin

Question 41

This intermediate of the TCA cycle can be converted into glucose in the liver during the fasting state

Answer 41

Malate

Question 42

These intermediates of the TCA cycle can be converted into amino acids

Answer 42

Oxaloacetate Alpha ketoglutarate

Question 43

Pyruvate carboxylase are primarily found in the___________ and is activated by

Answer 43

Liver, brain, and adipose tissue; acetyl CoA

Question 44

Pyruvate carboxylase deficiency leads to_______and causes

Answer 44

Lactic acid build up; hypotonia , delayed movement, ataxia