Block 1 Tca Cycle (Bondarenko)

Front 1

The TCA cycle is the final step where ______ of ______, _______, and ______ converge

Back 1

Oxidative metabolism
Carbohydrates
AA
FA

Front 2

_______ provides the majority of of ATP production

Back 2

TCA cycle

Front 3

Where does the TCA cycle occur?

Back 3

Mitochondria

Front 4

The TCA cycle provides precursors for ________ and ________

Back 4

gluconeogenesis
FA synthesis

Front 5

The TCA cycle provides building blocks for synthesis of some _____ and ______

Back 5

AA
Heme

Front 6

The TCA cycle is a traffic cycle, which means ______

Back 6

That molecules are entering and leaving

Front 7

The TCA completely oxidizes _____ to _____

Back 7

Acetyl CoA
CO2

Front 8

Glycolysis is the major source of _____ for the TCA cyle

Back 8

Carbons

Front 9

Which enzyme is the bridge between glycolysis and the TCA cycle?

Back 9

Pyruvate dehydrogenase

Front 10

Is the reaction of pyruvate to acetyl CoA a part of the TCA cycle?

Back 10

NO

Front 11

What does pyruvate dehydrogenase do?

Back 11

It converts pyruvate to acetyl CoA

Front 12

Is the conversion of pyruvate to acetyl CoA reversible?

Back 12

NO, IRREVERSIBLE

Front 13

Why is the reaction for the conversion of pyruvate to acetyl CoA an important step?

Back 13

Not only does it give rise to the TCA cycle, it is an important regulation site.

Front 14

How many coenzymes does pyruvate dehydrogenase have? and what are they.

Back 14

5
thiamine pyrophosphate, lipoic acid, CoA, FAD and NAD+

Front 15

What are the other members of the pyruvate dehydrogenase family? (2)

Back 15

Alpha-ketogluterate dehydrogenase
Alpha-keto acid dehydrogenase

Front 16

Which metal does thiamin pyrophosphate use to bind enzymes?

Back 16

Mg

Front 17

Is the binding of thiamine pyrophosphate weak?

Back 17

YES

Front 18

What strongly inhibits the absorption of thiamin?

Back 18

Alcohol

Front 19

What disease is caused by thiamin deficiency?

Back 19

Heart failure

Front 20

What are the high rate ATP production tissues that are affected by thiamine deficiency? (3)

Back 20

Heart muscle
Skeletal muscle
Nervous system

Front 21

Why is thiamin so important?

Back 21

Thiamin pyrophosphate is a coenzyme of pyruvate dehydrogenase. Without it, pyruvate to acetyl CoA is affected, leading to failure in tissues.

Front 22

WHat does phosphorylation do to pyruvate dehydrogenase?

Back 22

INHIBITION

Front 23

WHat activates protein kinase?

Back 23

High energy signals and by the product of: NADH, ATP and Acetyl CoA.

Front 24

WHat inhibits protein kinase?

Back 24

Low energy signals and by subrate: ADP, NAD, CoASH and pyruvate

Front 25

What activates phosphatase, which in turn activates PDC (muscle)

Back 25

Calcium

Front 26

What activates PDC in cardiac muscle?

Back 26

catecholamines

Front 27

Congenital lactic acidosis results from

Back 27

pyruvate dehydrogenase dificiency

Front 28

Pyruvate dehydrogenase is very important in the ______

Back 28

brain

Front 29

Does a pyruvate dehydrogenase deficiency affect both females and males?

Back 29

YES

Front 30

What happens to the pyruvate when one has a pyruvate dehydrogenase deficiency?

Back 30

The excess pyruvate is shunted to lactic acid by lactate dehydrogenase

Front 31

Why is it not good to shunt the excess pyruvate to lactic acid?

Back 31

The brain relies on TCA for energy and is sensitive to acidosis.

Front 32

Pyruvate dehydrogenase deficiency causes sever ________.

Back 32

Neonatal death

Front 33

Arsenite interferes with ____ and _____

Back 33

Glycolysis and TCA cycle

Front 34

Arsenic poisoning decreases production of ______

Back 34

ATP

Front 35

Arsenite inhibits enzymes that use ______ as cofactor

Back 35

Lipoic acid

Front 36

Arsenite forms stable complex with ______ of lipoic acid in pyruvate and alpha-ketogluterate dehydrogenases

Back 36

thiol group

Front 37

Formation of the stable complex with lipoic acid results in accumulation of what?

Back 37

pyruvate and lactate

Front 38

The accumulation of pyruvate and lactate affects the _______, causing _____ and ______

Back 38

Brain
neurological problems and death

Front 39

What is the first step of the TCA cycle?

Back 39

Formation of citrate

Front 40

Citrate is oxidized to ___________ by four dehydrogenases. What are they?

Back 40

oxaloacetate
1. Isocitrate dehydrogenase
2. Alpha-ketogluterate
3. dehydrogenase
4. Succinate dehydrogenase
Malate dehydrogenase

Front 41

What do the dehydrogenases of the citrate reaction do?

Back 41

They catalyze oxidation of substrate and reduction of NAD+ or FAD

Front 42

How many molecules of CO2 are created in the citrate reaction?

Back 42

2

Front 43

What is the final product of the citrate reaction?

Back 43

Oxaloacetate

Front 44

Citrate is produced by ______

Back 44

condensation of acetyl CoA and oxaloacetate.

Front 45

What inhibits citrate synthase?

Back 45

Citrate
NADH
Succinyl CoA

Front 46

What is regulation of citrate determined by?

Back 46

Availability of substrate

Front 47

What enzyme catalyzes citrate -> isocitrate?

Back 47

aconitase

Front 48

What can inhibit aconitase?

Back 48

flouroacetate

Front 49

Oxidation of isocitrate is catalyzed by ____ and is a rate limiting step.

Back 49

isocitrate dehydrogenase