M1-C1-L41 --> Pyruvate Dehydrogenase Complex

Front 1

The Pyruvate Dehydrogenase Complex provides Acetyl CoA to what?

Back 1

TCA and fatty acid synthesis

Front 2

The Pyruvate Dehydrogenase Complex is located where?

Back 2

Mitochondria

Front 3

What overal reaction does Pyruvate Dehydrogenase Complex carry out?

Back 3

Oxidative Decarboxylation

Front 4

What are the three enzymes that make up the Pyruvate Dehydrogenase Complex?

Back 4

1.) Pyruvate Decarboxylase
2.) Dihydrolipoyl Transacetylase
3.) Dihydrolipoyl Dehydrogenase.

Front 5

What is the pyruvate dehydrogenase reaction equation?

Back 5

Pyr + CoA + NAD+ <--> AcCoA + NADH + H+ + CO2

Front 6

Pyruvate must be changed to what before entering TCA?

Back 6

Acetyl CoA

Front 7

T/F - The conversion of pyruvate to Acetyl CoA and CO2 is reversible.

Back 7

F - It is irreversible.

Front 8

Pyruvate Dehydrogenase Complex Mechanism

Back 8

Answer

Front 9

Pyruvate Dehydrogenase Complex Mechanism

Back 9

Answer

Front 10

Pyruvate Dehydrogenase Complex Mechanism

Back 10

Answer

Front 11

Pyruvate Dehydrogenase Complex Mechanism

Back 11

Answer

Front 12

Pyruvate Dehydrogenase Complex Mechanism

Back 12

Answers

Front 13

After decarboxylation, the hydroxyethyl intermediate will bind to what?

Back 13

Thiamine pyrophosphate

Front 14

TPP is attached to, and a coenzyme of what enzyme?

Back 14

Pyruvate Decarboxylase (E1)

Front 15

What happens to the hydroxylethyl intermediate after it is transferred to lipoic acid.

Back 15

Becomes oxidized (-C=O)

Front 16

What must happen to the lipoic acid before it receives the acetyl group?

Back 16

Must be in reduced form (-SH)

Front 17

Lipoic Acid attached to the lysine residue is called what?

Back 17

Lipoamide

Front 18

Lipoic acid belongs to which PDH enzyme?

Back 18

Dihydrolipoyl transacetylase (E2)

Front 19

The acetyl group bound as a thioester (-C(=O)-S-Lipoic Acid) is transferred to where?

Back 19

CoA

Front 20

What is the final acetyl acceptor?

Back 20

CoASH

Front 21

The sulfhydryl form of lipoic acid is oxidized by what?

Back 21

FAD+

Front 22

FAD+ is on what which enzyme?

Back 22

Dihydrolipoyl dehydrogenase (E3)

Front 23

FADH2 is oxidized by what?

Back 23

NAD+ located on dihydrolipoyl dehydrogenase.

Front 24

What does NAD+ do in the Pyruvate Dehydrogenase mechanism?

Back 24

Oxidizes FADH2, then dissociate from the complex.

Front 25

Thiazolium Ring

Back 25

What is this called?

Front 26

Lipoamide is a dithiol which is subject to what type of reaction?

Back 26

Redox

Front 27

CoA is a derivative what?

Back 27

ADP

Front 28

What is the reactive group in CoA?

Back 28

Thiol group

Front 29

What is a catalytic cycle?

Back 29

Following the substrate reaction, where the enzymes and coenzymes are regenerated by more enzymatic steps.

Front 30

What are the five coenzymes of PDH Complex?

Back 30

1.) TPP
2.) Lipoate
3.) NAD+
4.) FAD+
5.) CoA

Front 31

What vitamin provides TPP

Back 31

Thiamin

Front 32

What vitamin provides for CoA

Back 32

Pantothenate

Front 33

What vitamin provides for FAD

Back 33

Riboflavin

Front 34

What vitamin provides for NAD

Back 34

Niacin

Front 35

What are the mechanisms regulating Pyruvate Dehydrogenase Complex activity?

Back 35

1.) Product feedback inhibition
2.) Inactivation by phosphorylation

Front 36

What enzyme will phosphorylate the PDH complex into inactive form?

Back 36

Kinase

Front 37

What are the allosteric activators of kinase

Back 37

1.) NADH
2.) Acetyl CoA

Front 38

What are the allosteric inhibitors of kinase

Back 38

1.) ADP
2.) Pyruvate
3.) CoA
4.) NAD

Front 39

What enzyme will dephosphorylate the PDH complex into active form?

Back 39

Phosphotase

Front 40

What are some medical conditions associated with PDH complex?

Back 40

1.) Thiamine deficiency (dietary)
2.) Pyruvate DH deficiency (genetic)
3.) Shock - tissue hypoxia leads to shut down of PDH complex

Front 41

What are some symptoms associated with Thiamine Deficiency?

Back 41

1.) Elevated serum pyruvate
2.) Reduced pyruvate oxidation (critical for brain)
3.) Loss of neural function

Front 42

What are some diseases associated with Thiamine Deficiency (diet)?

Back 42

1.) Alcoholism
2.) Beri Beri

Front 43

PyrDH deficiency has what kind of symptoms?

Back 43

1.) Elevated serum pyruvate, alanine, lactate
2.) Defective catalytic or regulatory subunit

Front 44

When is PyrDH deficiency detected?

Back 44

During childhood

Front 45

What are some diseases associated with PyrDH deficiency?

Back 45

Chronic Lactic Acidosis