test 3

Question 1

in muscle and bacteria, pyruvate is reduced to…

Answer 1

lactate

Question 2

one of most critical steps in EMP pathway

Answer 2

fructose bisphosphate aldolase

Question 3

what happens to pyruvate in yeast?

Answer 3

cleaved to CO2 and acetaldehyde and then converted to ethanol

Question 4

the three irreversible steps in EMP

Answer 4

1. pyruvate kinase (PEP to pyruvate)
2. phosphofructokinase (F-6-P to F-1,6-bP)
3. hexokinase (Glu to G-6-P)

Question 5

Glycogen synthesis uses which 2 enzymes?

Answer 5

1. ADP glucose phosphorylase

2. glycogen synthase

Question 6

Why does the pentose phosphate pathway generate NADPH?

Answer 6

for reducing power in converting alpha-ketoglutarate to glutamate OR incorporation of acetate into fatty acids

Question 7

general equation of pentose phosphate pathway (PPP)?

Answer 7

3 G6P –> 2F6P + 1 Ga3P

Question 8

glycogen is cleaved by

Answer 8

glycogen phosphorylase

Question 9

starch is cleaved by

Answer 9

beta-amylase (cuts to maltose units)

Question 10

maltose is cleaved by

Answer 10

amylotransferase, alpha-amylase, and 4-alpha-glucanotransferase

Question 11

what happens to TCA intermediates?

Answer 11

they are used for anabolic reactions

Question 12

purpose of the glyoxylate cycle?

Answer 12

replenishes oxaloacetate

Question 13

glyoxylate shunt equation

Answer 13

2 acetyl CoA –> 1 malate

Question 14

isocitrate lyase converts what to what

Answer 14

isocitrate to succinate and glyoxylate

Question 15

what does malate synthase do?

Answer 15

couples acetyl coA and glyoxylate for form malate

Question 16

role of F1F0 type ATP synthase

Answer 16

generation of ATP from the proton motive force (PMF)

Question 17

two parts of F1F0 type ATP synthase

Answer 17

1. F1 - attached to membrane by pore complex called F0 (synthesizes ATP)
2. F0 - conductor of H+ across membrane

Question 18

how many H+ to generate 1 ATP?

Answer 18

3-4

Question 19

when ATPase works in reverse it pumps protons out of cell and generates PMF to drive what?

Answer 19

flagellar movement

Question 20

energy yield depends on what factors?

Answer 20

• cytochrome system
• terminal electron acceptor type
• efficiency of ATP synthase

Question 21

total yield per glucose molecule?

Answer 21

~38 ATP per glucose in respiring bacteria

Question 22

chemoautotroph

Answer 22

obtains C from organic compounds but obtains E from oxidation of inorganic compounds

Question 23

photoautotrophs

Answer 23

obtains C from organic compounds but obtains E from light

Question 24

what is the sodium motive force and when is it used?

Answer 24

when ATPase couples ATP synthesis to movement of Na+ (NOT H+)

it occurs in alkaline conditions

Question 25

photoautotroph bacteria

Answer 25

• carry out photosynthesis
• convert E from sun, CO2 and water to organic compounds
• use bacteriochlorophyll
• derive H from H2S

Question 26

Photoheterotrophic bacteria

Answer 26

-combine photosynthetic and catabolic process for metabolism
-CANNOT fix CO2 to organic materials
use light for E
-contain bacteriochrolophyll and bacteriorhodopsin

Question 27

2 branches of anaerobic TCA

Answer 27

1. one branch acts as reductive pathway to reverse succinate to oxaloacetate
2. another path converts oxaloacetate to alpha-ketoglutarate oxidatively

Question 28

what is the purpose of fermentation?

Answer 28

to replenish NAD+ depleted during glycolysis

Question 29

the phosphoketolase/monophosphate pathway produces?

Answer 29

lactate + ethanol + CO2

Question 30

what is the Pasteur effect?

Answer 30

in resting yeast cell suspension fermenting glucose, introduction of O2 ceases ethanol formation
(not exhibited by growing yeast cells)

Question 31

Two types of lactic acid fermentations:

Answer 31

1. homofermentative: produce primarily lactic acid

2. heterofermentative: produce lactic acid + other product

Question 32

Mixed acid fermentation

Answer 32

in anaerobic conditions and absence of alternate e acceptors, enterobacteriaceae ferment glucose to a mixture of:

• acetic acid
• formic acid
• lactic acid
• succinic acid
• ethanol

(Acetate and formate as major products)