chapter nine part two

Question 1

Krebs (citric acid) cycle

Answer 1

2C acetyl CoA + 4C oxaloacetate (oxaloacetic acid) –> 6C citric acid

Question 2

how many Krebs cycles per glucose

Answer 2

2

Question 3

vitamins needed for coenzyme NAD

Answer 3

niacin

Question 4

vitamins needed for coenzyme FAD

Answer 4

riboflavin

Question 5

vitamins needed for coenzyme CoA

Answer 5

pantothenic acid

Question 6

products of pyruvate oxidation

Answer 6

2 acetyl CoA
2 CO2
2 NADH + H+

Question 7

products of one acetyl CoA molecule per Krebs cycle

Answer 7

2 CO2
3 NADH
1 ATP (by SLP)
1 FADH2

Question 8

products of one acetyl CoA per glucose

Answer 8

4 CO2
6 NADH
2 ATP
2 FADH2

Question 9

how are NADH and FADH2 changed to ATP energy

Answer 9

electron transport chain - use high-energy electrons carried by NADH and FADH2
oxidative phosphorylation - ADP to ATP

Question 10

how many ATP does oxidative phosphorylation produce?

Answer 10

30-32 ATP

Question 11

what does oxidative phosphorylation involve?

Answer 11

free-energy change during electron transport

Question 12

electron tranport chain

Answer 12

electrons move down chain of multi protein complexes, releasing free energy at every step
- includes cytochromes
- proteins and prosthetic groups

Question 13

what is the final electron accepter?

Answer 13

oxygen - reacts w/ H+ to form water

Question 14

where NADH enters the chain, how many ATP are made?

Answer 14

3 ATP per molecule

Question 15

where FADH2 enters chain, how many ATP are made?

Answer 15

2
- comes later into chain and doesn’t build up as good as a gradient

Question 16

ATP synthase

Answer 16

enzyme that makes ATP from ADP and P
- uses energy of existing ion gradient to power synthesis
- difference in concentration of H+ on either side of mitochondrial emmbrane

Question 17

chemiosmosis

Answer 17

process in which energy stored in the form of H+ gradient across membrane is used to drive cellular work like synthesis of ATP

Question 18

chemiosis in mitochondria

Answer 18

energy for gradient formation comes from exergonic redox reactions along ETC, ATP synthesis work is performed
- chemical energy converted to ATP energy

Question 19

chemiosis in chloroplasts

Answer 19

ATP generated during photosynthesis
- light energy converted to ATP energy

Question 20

chemiosis in bacteria and other prokaryotes

Answer 20

plasma membrane generates H+ gradient across PM

Question 21

proton motive force and pump

Answer 21

force that promotes movement of protons across membrane down electrochemical potential
- force drives H+ back across membrane through H+ channels provided by ATP synthase

Question 22

total ATP produced from glucose molecule in heart muscle, kidneys, and liver

Answer 22

38 - higher end

Question 23

total ATP produced from glucose molecule elsewhere

Answer 23

36 - lower end

Question 24

fermentation

Answer 24

harvesting chemical energy w/o O2 or ETC to produce ATP (less efficient)

Question 25

2 types of fermentation

Answer 25

1. alcoholic fermentation of glucose
2. lactic acid fermentation

Question 26

alcoholic fermentation of glucose

Answer 26

pyruvate converted to ethanol by:
1. releasing CO2 from pyruvate, which is converted to 2C compound acetaldehyde
2. acetaldehyde reduced by NADH to ethanol

Question 27

lactic acid fermentation

Answer 27

pyruvate reduced directly by NADH to form lactate, regenerating NAD+ w/o release of CO2
1. SLP during glycolysis
- NADH used in conversion of pyruvate to lactate, so 2 ATP are the entire output of energy, vs. 32 if oxygen is present
2. excess lactate shuttled to other tissues for oxidation or to liver/kidneys for production of glucose/glycogen

Question 28

obligate anaerobes

Answer 28

carry out only fermentation and anaerobic respiration

Question 29

facultative anaerobes

Answer 29

organisms that can make enough ATP to survive using fermentation or respiration

Question 30

control of cellular respiration

Answer 30

feedback inhibition - end product of anabolic pathway inhibits enzyme that catalyzes an early step of the pathway

Question 31

negative feedback mechanisms

Answer 31

if ATP concentration begins to drop, cellular respiration speeds up and vise versa

Question 32

phosphofructokinase

Answer 32

• negative feedback - catalyzes step 3 of glycolysis
• can speed/slow catabolic process
• allosteric enzyme w/ receptor sites for specific inhibitors/activators
• inhibited by ATP, stimulated by AMP

Question 33

what types of carriers are present within the ETC?

Answer 33

FeS and cyto C carriers

Question 34

is glucose oxidized or reduced to form pyruvate?

Answer 34

oxidized

Question 35

when is the only time FAD is necessary in cellular respiration?

Answer 35

Krebs cycle