Chapter 3 Study Questions (Part 4)

Question 1

what are the three pathways of cellular respiration?

Answer 1

1. glycolysis
2. Krebs Cycle
3. oxidative phosphorylation

Question 2

the Krebs cycle of cellular respiration, aka

Answer 2

citric acid cycle, tricarboxylic cycle, TCA cycle

Question 3

TCA cycle completes the _____ of _______ that was started by _____

Answer 3

TCA cycle complete the oxidation of glucose that was started by glycolysis

Question 4

what enzyme has the greatest regulatory effect in glycolysis?

Answer 4

PFK

Question 5

where in the cell does the TCA cycle occur?

Answer 5

interior, mitochondrial matrix

Question 6

what are the sources used to make acetyl CO-A?

Answer 6

pyruvate + carbon = acetyl group
acetyl group + coenzyme A = acetyl-CoA

Question 7

what happens to all the carbon that enters as acetyl CoA?

Answer 7

2 CO2 are released from each acetyl CoA

Question 8

what do we get from the TCA cycle?

Answer 8

generates NADHs and the electrons used in oxidative phos. to make ATP

Question 9

what do we use to feed the TCA cycle?

Answer 9

pyruvate

Question 10

where do we get pyruvate from?

Answer 10

glycolysis

Question 11

how many carbons do we start with in TCA?

Answer 11

3

Question 12

how do we lose one carbon in TCA?

Answer 12

CO2.

Question 13

what happens when CO2 and water combine?

Answer 13

it makes carbonic acid. increases the protons and decreases pH, causing acidic conditions

Question 14

what happens to ALL the carbon that enters as acetyl COA?

Answer 14

it’s lost as CO2. we only keep electrons

Question 15

why is FAD used instead of NAD in the Krebs cycle and why does it matter?

Answer 15

because FAD is tethered to the inner mitochondrial membrane, not inside the matrix

Question 16

what does the TCA cycle ultimately do?

Answer 16

completes oxidation of glucose, captures electrons with NAD and FAD

Question 17

what does the TCA cycle ultimately do? (2)

Answer 17

completes oxidation of glucose, captures electrons with NAD and FAD

Question 18

why do we need to exhale?

Answer 18

to keep our bodies from making carbonic acid and getting too acidic

Question 19

where do the steps in oxidative phosphorylation occur in the cell?/

Answer 19

inner membrane of the mitochondria

Question 20

what two processes make up oxidative phosphorylation

Answer 20

1. electron transport chain
2. chemiosmosis

Question 21

what is the role of O2?

Answer 21

the final electron acceptor

Question 22

how is ATP produced?

Answer 22

throughout the cycle, and primarily in ox. phos.

Question 23

what is the role of the ETC and how does it do that?

Answer 23

role: creates a proton gradient

how: proton pump

Question 24

what is the role of chemiosmosis and how does it do that?

Answer 24

what: convert kinetic to chemical energy to make ATP.

how: gradient. redox reactions, so we need oxygen present.

Question 25

what form of energy is produced during glycolysis?

Answer 25

a couple electrons and ATPs

Question 26

what form of energy is produced during the TCA cycle?

Answer 26

FAD
NADH
CO2
e-

Question 27

what form of energy is captured during oxidative phosphorylation?

Question 28

which pathway (glycolysis, TCA, oxidative phosphorylation) produces the most ATP and which produces the least?

Answer 28

glycolysis = TCA < oxidative phosphorylation

Question 29

how does cellular respiration operate under aerobic and anaerobic conditions?

Question 30

how is ATP produced in the absence of oxygen?

Question 31

role of NAD, FAD, and O2 in cellular respiration?