unit 3 exam

Question 1

what compounds are consumed and produced in glycolysis

Answer 1

2 ATP consumed, 4 ATP produced, 2 NADH produced

Question 2

What are the payoff steps of glycolysis?

Answer 2

oxidizing glyceraldehyde (energy stored in phosphate bond and NADH)
energy from phosphoenolpyruvate (PEP)

Question 3

How many kinases are involved in glycolysis?

Answer 3

3

Question 4

How is phosphofructokinase regulated and what does it do?

Answer 4

when there are high levels of ATP, fatty acids inhibit the enzyme
when there are high levels of AMP, ADP stimulates the enzyme
catalyzes phosphorylation

Question 5

If an enzyme pathway is blocked, which compound will accumulate?

Answer 5

the compound before the largest positive change in free energy

Question 6

What are the 2 pathways of fermentation?

Answer 6

glucose–>pyruvate–>lactate
glucose–>pyruvate–>aldehyde–>ethanol

Question 7

In anaerobic conditions:
Which step generates NADH?
Which step generates NAD+?

Answer 7

NADH generated going from glucose to pyruvate because consumes NAD+ to drive reaction
NAD+ generated going from aldehyde to the ethanol

Question 8

What drives the citric acid cycle?

Answer 8

reduction of NAD+

Question 9

How many steps of the citric acid cycle form CO2?

Answer 9

2

Question 10

How many steps of the citric acid cycle involve oxidation?

Answer 10

4

Question 11

What regulates citrate synthase?

Answer 11

ATP and NADH

Question 12

What do dehydrogenases do?

Answer 12

catalyze oxidation

Question 13

What are the signs of a thiamine deficiency?

Answer 13

decreased activity of pyruvate dehydrogenase complex

Question 14

function of complex I of pyruvate dehydrogenase and its key component

Answer 14

catalyzes oxidation of NADH and reduction of UQ
- pumps 4 H+
- key component is thiamine

Question 15

function of complex II of pyruvate dehydrogenase and its key component

Answer 15

catalyzes oxidation of succinate and reduction of UQ
- only membrane inserted enzyme
- no pumping of H+
- key component is lipoic acid

Question 16

function of complex III of pyruvate dehydrogenase and its key component

Answer 16

oxidizes ubiquinol and reduces cyt C
- 4 H+ pumped for every 2 electrons transferred to cyt c
- key component is FAD

Question 17

What is cytochrome c?

Answer 17

a protein that shuttles between complexes III and IV

Question 18

function of complex IV of pyruvate dehydrogenase

Answer 18

catalyzes reduction of O2–>H2O
- 4 electron reduction
- accumulates the 4 electrons from cyt c
- pumps 2 H+/every 2 electrons or 4 H+/each O2

Question 19

Why can pyruvate dehydrogenase have the same complex III as alpha-KG dehydrogenase?

Answer 19

They have identical substrates and products

Question 20

What does decarboxylation do?

Answer 20

removes a CO2

Question 21

When considering standard reduction potentials, which compound will be reduced?

Answer 21

The compound with the more positive standard reduction potential

Question 22

What role does light energy play in photosynthesis?

Answer 22

used to dissociate water into O2, protons, and high energy electrons

Question 23

What do amino transferases do?

Answer 23

catalyze synthesis of aspartate and alpha-KG

Question 24

Where does arginine–>ornithine catalysis take place?

Answer 24

the urea cycle

Question 25

Why do electrons transported from FADH2 to the electron transport chain produce fewer ATP than electrons transported into complex I from NADH?

Answer 25

because FADH2 enters at complex II which does not pump protons

Question 26

What does DNP do?

Answer 26

increases rate of NADH oxidation increases rate of citric acid cycle can decrease ATP production *** oxygen consumption unaffected, electron transfer unaffected

Question 27

characteristics of ubiquinone

Answer 27

soluble in membranes accepts electrons from complex I accepts electrons from complex II

Question 28

citric acid cycle functions

Answer 28

form intermediates like alpha-KG that can be used for amino acid synthesis generate NADH and FADH2 substrate level phosphorylation of GDP to GTP

Question 29

why is the conversion of malate and NAD+ to oxaloacetate and NADH favorable?

Answer 29

concentration of oxaloacetate extremely low relative to malate

Question 30

carnitine purpose

Answer 30

essential for transport of fatty acids across mitochondrial membrane

Question 31

urea cycle components

Answer 31

amino acids undergo transamination to form glutamate and alpha keto acids alanine carries ammonia from skeletal muscle to liver glutamate combines with ammonia to form glutamine which travels to liver through blood stream

Question 32

characteristics of mitochondrial electron transport

Answer 32

generates most reactive oxygen species and may contribute to aging

Question 33

functions of ATP synthase

Answer 33

catalyze hydrolysis/synthesis of ATP certain subunits rotate during synthesis/hydrolysis release of ATP requires proton gradient

Question 34

calvin cycle function

Answer 34

NADPH and ATP used to reduce C-O bonds

Question 35

What decreases energy density?

Answer 35

increasing percentage oxidized bonds

Question 36

mitochondria processes

Answer 36

citric acid cycle reduction of O2-->H2O fatty acid oxidation

Question 37

how do the pyruvate and alpha-KG dehydrogenase complexes preserve energy?

Answer 37

in a thiol ester bond to co-enzyme A

Question 38

how is light energy transported out of chloroplast in eukaryotic plant cells?

Answer 38

as chemical energy in dihydroxy acetone phosphate

Question 39

How many acetyl co-A, NADH, and FADH2 formed from a 12 carbon fatty acid

Answer 39

6 acetyl co-A 5 NADH 5FADH2

Question 40

what is ATP used for in the urea cycle?

Answer 40

creates a high energy intermediate from bicarbonate so that adding ammonia to the bicarbonate is favorable

Question 41

glycolysis reactions

Answer 41

NAD+-->NADH PEP+ADP-->ATP 1,3-bis+ADP-->ATP

Question 42

which compound produces the most energy if completely oxidized to CO2

Answer 42

ethanol

Question 43

how much acetyl CoA is formed from 1 glucose going through the glycolysis dehydrogenase complex

Answer 43

2 acetyl CoA

Question 44

pyruvate dehydrogenase path

Answer 44

pyruvate-->lipoic acid-->FADH2-->NADH

Question 45

how much CO2, NADH, and FADH2 is produced each turn of the citric acid cycle

Answer 45

2 CO2 3 NADH 1 FADH2

Question 46

what are the net gains of oxidizing the acetate of acetyl CoA in the citric acid cycle

Answer 46

NADH, CO2, GTP

Question 47

compounds in urea cycle

Answer 47

aspartate, ATP, carbamoyl phosphate

Question 48

what is the final electron acceptor of electron transport in the mitochondria?

Answer 48

O2