Carbohydrate Metabolism: Glycolysis, the Citric Acid Cycle, and Oxidative Phosphorylation (9/22) w/German

Question 1

What are the 5 pathways of glucose metabolism?

Answer 1

1. glycolysis
2. Pentose phosphate pathway
3. Pyruvate dehydrogenase complex
4. Citric Acid Cycle
5. Oxidative phosphorylation

Question 2

What are the 3 products of glycolysis?

Answer 2

ATP
NADH
Pyruvate

Question 3

What are the 2 products of the pentose phosphate pathway?

Answer 3

NADPH

Ribose sugars

Question 4

What is the product of the pyruvate dehydrogenase complex?

Answer 4

Acetyl CoA

Question 5

What are the products of the citric acid cycle?

Answer 5

NADH
FADH2
ATP

Question 6

What is the product of oxidative phosphorylation?

Answer 6

ATP

Question 7

What is cellular respiration?

Answer 7

the cellular pathways that synthesize ATP by moving electrons from glucose (or other carbons) to oxygen

Question 8

What are the 3 stages of cellular respiration?

Answer 8

1. Glycolysis
2. Citric acid cycle
3. Oxidative phosphorylation

Question 9

T/F: Glycolysis is an aerobic process.

Answer 9

False. Glycolysis is an anaerobic process.

Question 10

T/F: The citric acid and oxidative phosphorylation are both aerobic processes.

Answer 10

True.

Question 11

What are the 2 phases of glycolysis?

Answer 11

• Preparatory (phoshorylation)

- Payoff (oxidation-reduction)

Question 12

T/F: glycolysis occurs in the absence of oxygen.

Answer 12

True.

Question 13

What occurs during the preparatory phase of glycolysis?

Answer 13

phosphorylation of glucose and its conversion to glyceraldehyde 3-phosphate.

Question 14

What occurs during the payoff phase of glycolysis?

Answer 14

Oxidative conversion of glyceraldehyde 3-phosphate to pyruvate and the coupled formation of ATP and NADH.

Question 15

What are the net products of the payoff phase of glycolysis?

Answer 15

• 2 pyruvate
• 2 ATP
• 2 NADH and H+

Question 16

T/F: All dietary carbohydrates are broken down into glucose.

Answer 16

False. Not all dietary carbohydrates are broken down to glucose.

Question 17

T/F: Extracelluar signals and intracellular substrate concentrations regulate glycolysis.

Answer 17

True.

Question 18

Why is NADPH so important?

Answer 18

NADPH is necessary for reductive biosynthesis (creating fatty acids) and free radical protection.

Question 19

What regulates the pentose phosphate pathway?

Answer 19

Excess NADPH.

Question 20

What are the fates of Pyruvate after glycolysis?

Answer 20

Fermentation in anaerobic conditions

Citric acid cycle in aerobic conditions

Question 21

What is the purpose of fermentation?

Answer 21

the regeneration of NAD+ in anaerobic conditions, which allows glycolysis to continue.

Question 22

T/F: Without NAD+, glycolysis has no electron acceptor.

Answer 22

True

Question 23

T/F: Lactate is the electron acceptor of NADH produced in glycolysis.

Answer 23

True.

Question 24

T/F: Lactate is readily transported out of cells and into the blood.

Answer 24

True.

Question 25

T/F: Lactate is the substrate for liver gluconeogenesis.

Answer 25

True.

Question 26

T/F: Lactate is the substrate for liver gluconeogenesis.

Answer 26

True.

Question 27

T/F: The mitochondria are involved in apoptosis.

Answer 27

True.

Question 28

What is apoptosis?

Answer 28

Programmed cell death.

Question 29

What initiates apoptosis?

Answer 29

The release of cytochrome C from mitochondria into the cytoplasm activating a casacade of caspases.

Question 30

What is pyruvate converted to in the mitochondria?

Answer 30

Acetyl-CoA

Question 31

Pyruvate is converted to Acetyl-CoA by what complex?

Answer 31

Pyruvate dehydrogenase complex.

Question 32

T/F: The citric acid cycle oxidizes electron carriers.

Answer 32

False. The citric acid cycle reduces electron carriers.

Question 33

What 2 substrates drive the citric acid cycle?

Answer 33

Acetyl-CoA and oxaloacetate.

Question 34

How many steps are in the citric acid cycle?

Answer 34

8

Question 35

Does the citric acid cycle require O2?

Answer 35

Yes, but indirectly. If electron carriers are not used in the ETC, they build up which will then stop the citric acid cycle.

Question 36

How many turns per glucose molecule does the citric acid cycle preform?

Answer 36

2 turns per glucose molecule.

Question 37

How is the citric acid cycle regulated?

Answer 37

Allosterically by substrates and products.

Question 38

How is the citric acid cycle regulated?

Answer 38

Allosterically by substrates and products.

Question 39

At what steps is the citric acid cycle regulated?

Answer 39

The most exergonic steps.

Question 40

What does oxidative phosphorylation create?

Answer 40

ATP.

Question 41

What happens during the 4 stages of oxidative phospohrylation?

Answer 41

1. reduced substrate donates electron. 2. electron carriers pump H+ out as electrons flow to O2. 3. Energy of electron flow stored as electrochemical potential. 4. ATP synthase uses electrochemical potential to synthesize ATP.

Question 42

What are the 3 electron transfer types?

Answer 42

1. direct electron (Fe3+ reduced to Fe2+) 2. hydrogen atom (H+ & e-) 3. hydride ion (H-)

Question 43

T/F: NADH can carry both electrons and protons.

Answer 43

True

Question 44

What are the 5 types electron carriers?

Answer 44

``` NADH Flavoproteins Ubiquinone cytocromes iron-sulfur proteins ```

Question 45

Which electron carrier can carry both electrons and protons, is lipid soluble, and membrane mobile?

Answer 45

Ubiquinone does ALL that.

Question 46

Which electron carrier has 3 types, is classified by light absorption, and only accepts electrons?

Answer 46

Cytochromes. 3 types: a, b, & c c is mobile

Question 47

Which electron carrier only accepts electrons?

Answer 47

iron-sulfur proteins.

Question 48

What does ATP synthase use to create ATP?

Answer 48

H+ movement.

Question 49

Where does the malate-aspartate shuttle take place?

Answer 49

liver, kidney, & heart

Question 50

Where does the glycerol 3-phosphate shuttle take place?

Answer 50

brain and skeletal muscle

Question 51

What does the pentose phosphate pathway synthesize?

Answer 51

NADPH | Ribose sugars

Question 52

T/F: The outer membrane of the mitochondira is freely permeable to small molecules and ions.

Answer 52

True.

Question 53

T/F: The inner membrane is impermeable to most small molecules and ions including H+.

Answer 53

True.