CITRIC ACID CYCLE

Question 1

Also known as Krebs cycle or TCA Cycle; key metabolic pathway

Answer 1

Citric Acid Cycle

Question 2

Conversion of glucose to pyruvate

Answer 2

Glycolysis

Question 3

Converts pyruvate to acetyl-CoA

Answer 3

Pyruvate Dehydrogenase

Question 4

Electron carrier in electron transport chain

Answer 4

Coenzyme Q

Question 5

Generates ATP during oxidative phosphorylation

Answer 5

ATP Synthase

Question 6

Electron carrier; reduced to NADH

Answer 6

NAD+

Question 7

Electron carrier; reduced to FADH2

Answer 7

FAD

Question 8

Site of citric acid cycle

Answer 8

Mitochondrial Matrix

Question 9

Generates ATP during oxidative phosphorylation

Answer 9

Electron Transport Chain

Question 10

ATP generation via electron transport chain

Answer 10

Oxidative Phosphorylation

Question 11

Citric Acid Cycle enzymes

Answer 11

Citrate synthase, aconitase,
isocitrate dehydrogenase,
alpha-ketoglutarate dehydrogenase complex, succinate thiokinase, succinate dehydrogenase, Fumatase,
Malate dehydrogenase

Question 12

Key regulatory enzyme in citric acid cycle

Answer 12

Alpha-Ketoglutarate Dehydrogenase

Question 12

Converts succinyl-CoA to succinate

Answer 12

Succinyl-CoA Synthetase

Question 13

Converts malate to oxaloacetate

Answer 13

Malate

Question 14

Citric Acid Cycle regulation

Answer 14

Feedback inhibition by ATP, NADH, and Succinyl-CoA
Allosteric control by citrate synthase and isocitrate dehydrogenase
Substrate availability like acetyl-CoA and oxaloacetate

Question 14

Replenish citric acid cycle intermediates

Answer 14

Anaplerotic reactions

Question 15

Remove citric acid cycle intermediates

Answer 15

Cataplerotic reactions

Question 16

Key regulatory enzyme

Answer 16

Citrate synthase

Question 17

Converts isocitrate to alpha-ketoglutarate

Answer 17

Isocitrate dehydrogenase

Question 18

Citric acid cycle intermediate and combined with Acetyl-CoA

Answer 18

Oxaloacetate

Question 19

Converts fumarate to malate

Answer 19

fumarase

Question 20

Exchanges ATP and ADP across mitochondrial membrane

Answer 20

ATP/ADP translocase

Question 20

Converts oxaloacetate to phosphoenolpyruvate

Answer 20

Phosphoenolpyruvate carboxykinase

Question 21

Citric Acid Cycle generates?

Answer 21

10 ATP
3 NADH
1 FADH2
2 CO2

Question 22

Inputs of Citric Acid Cycle

Answer 22

Acetyl-CoA, H20, O2

Question 23

ATP/ADP ratio

Answer 23

Regulates citric acid cycle activity

Question 24

Citric Acid Cycle connection to electron transport chain

Answer 24

Reducing equivalents; NADH and FADH2 generated in citric acid cycle fuel electron transport chain

Question 25

Citric Acid intermediates:

Answer 25

1. Citrate 2. Isocitrate 3. Alpha-ketoglutarate 4. Succinyl-CoA 5. Succinate 6. Fumarate 7. Malate 8. Oxaloacetate

Question 26

Occurs in advanced liver disease, leads to loss of consciousness, coma, and convulsion

Answer 26

Hyperammonemia

Question 27

Depletes the citric acid cycle intermediates and inhibits the oxidative decarboxylation of alpha-ketoglutarate

Answer 27

Ammonia

Question 28

Entry of carbon?

Answer 28

Anaplerosis

Question 29

Exit of carbon?

Answer 29

Cataplerosis

Question 30

found in some plants; inhibits aconitase causing the accumulation of citrate

Answer 30

Fluoroacetate

Question 31

Inhibits the reaction, causing substrate alpha-ketoglutarate to accumulate

Answer 31

Arsenite

Question 32

4 essential B vitamins in Citric Acid Cycle

Answer 32

1. Riboflavin (FAD) 2. Niacin (NAD+) 3. Vitamin B1 (thiamin) 4. Pantothenic acid

Question 33

cofactor for succinate dehydrogenase

Answer 33

FAD

Question 34

electron acceptor for isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, malate dehydrogenase

Answer 34

NAD+

Question 35

coenzyme for decarboxylation in the alpha-ketoglutarate dehydrogenase reaction

Answer 35

Thiamin (Vit. B1)

Question 36

esterified to carboxylic acids to form acetyl CoA and succinyl-CoA

Answer 36

Pantothenic acid

Question 37

Citric Acid Cycle is both

Answer 37

Oxidative & Synthetic process (amphibolic)

Question 38

Inhibit the reaction of the succinate to Fumarate

Answer 38

Malonate

Question 39

Citric Acid Cycle takes part in...

Answer 39

Gluconeogenesis Transamination Deamination

Question 40

An important substrate for gluconeogenesis, enters the cycle via oxidation to pyruvate and carboxylation to oxaloacetate

Answer 40

Lactate

Question 41

Important anaplerotic substances

Answer 41

Glutamine & Glutamate

Question 42

Major glucogenic product of rumen fermentation

Answer 42

Propionate

Question 43

Citric Acid takes part in ...

Answer 43

Fatty Acid Synthesis

Question 44

Major substrate for long chain fatty acid synthesis

Answer 44

Acetyl-CoA

Question 45

the source of half the NADPH required for fatty acid synthesis

Answer 45

Malic enzyme