Biochemistry Block Iii: Pyruvate Dehydrogenase And Tca Cycle

Front 1

Multienzyme complex located in the inner MM that catalyzes the oxidation of pyruvate to acetyl coA and NADH

Back 1

Pyruvate Dehydrogenase Complex

Front 2

The PDC has two tightly bound regulatory enzymes, what are they?

Back 2

PDK and PDP

Front 3

Which enzyme of PDC is named pyruvate dehydrogenase (decarboxylase)?

Back 3

E1

Front 4

Which enzyme of PDC is named lipoamide acetyl transferase (dihydrolipoyl transacylase)?

Back 4

E2

Front 5

Which enzyme of PDC is named Dihydrolipoyl Dehydrogenase (lipoamide dehydrogenase)?

Back 5

E3

Front 6

What is the coenzyme of E1 (PD)?

Back 6

TPP (from vitamin B1)

Front 7

What are the two coenzymes of E2 (LAT, DT)?

Back 7

Lipoic Acid and CoASH

Front 8

What are the coenzymes of E3 (DD, LD)?

Back 8

FAD and NAD

Front 9

The PDC is _______ by phosphorylation.

Back 9

Inactivated

Front 10

The PDC is ________ by dephosphorylation.

Back 10

Activated

Front 11

Which three things allosterically activate PDK, which phosphorylates the PDC?

Back 11

ATP, Acetyl CoA and NADH

Front 12

________ is a strong activator of PDP. Turns PDC on.

Back 12

Calcium

Front 13

Pyruvate dehydrogenase complex deficiency causes __________.

Back 13

Lactic Acidosis

Front 14

How does insulin activate PDC?

Back 14

Insulin triggers increased Ca2+ levels in the mitochondria

Front 15

The TCA cycle takes place where?

Back 15

Mitochondrial matrix

Front 16

Citrate, NADH, and Succinyl CoA all have what effect on citrate synthase?

Back 16

Inhibitory

Front 17

What are the three rate limiting enzymes in the TCA Cycle?

Back 17

Citrate Synthase, Isocitrate Dehydrogenase, and α-ketoglutarate dehydrogenase

Front 18

Citrate is isomerized to isocitrate by _______.

Back 18

Aconitase

Front 19

Converts Acetyl CoA + OAA into Citrate

Back 19

Citrate Synthase

Front 20

Multienzyme complex of TCA cycle v. similar to PDC

Back 20

α-ketoglutarate dehydrogenase

Front 21

This enzyme converts Fumarate to L-Malate in a hydration reaction: Deficiency usually results in death:

Back 21

Fumarase

Front 22

What activates citrate synthase?

Back 22

ADP

Front 23

What deactivates isocitrate dehydrogenase?

Back 23

NADH and ATP

Front 24

What activates isocitrate dehydrogenase?

Back 24

ADP and Ca2+

Front 25

What deactivates α-ketoglutarate dehydrogenase

Back 25

ATP, GTP, NADH, Succinyl CoA

Front 26

What activates α-ketoglutarate dehydrogenase?

Back 26

Ca2+

Front 27

Pyruvate is converted to OAA by which enzyme? What does this reaction require?

Back 27

Pyruvate carboxylase - Biotin

Front 28

What two things inhibit PDC?

Back 28

NADH and Acetyl CoA

Front 29

________ activate PDC by increasing Ca++ that stimulate PDP that dephosphorylates PDC and activates the enzyme.

Back 29

Insulin

Front 30

The brain relies on _________ _______ almost exclusively under fed conditions.

Back 30

Glucose Oxidation

Front 31

TPP is required for ________ of pyruvate.

Back 31

Decarboxylation

Front 32

Which subunit of PDC requires CoA?

Back 32

E2

Front 33

Which subunit of PDC requires TPP?

Back 33

E1

Front 34

What would happen to PDC if Acetyl CoA levels increased?

Back 34

PDC activity would decrease due to phosphorylation.

Front 35

What contribultes most to regulting the activity of the enzymes in the TCA cycle?

Back 35

ATP