Cellular Respiration Part 2

Question 1

What occurs during Krebs Stage 1?

Answer 1

two carbons in the acetate fragment of acetyl-CoA are condensed with the 4-carbon compound oxaloacetate producing citrate

Question 2

What occurs during Krebs Stage 2?

Answer 2

citrate is further oxidized to release CO2 and produce NADH with each oxidative decarboxylation

Question 3

What occurs during Krebs Stage 3?

Answer 3

oxaloacetate is regenerated so that the cycle can continue producing NADH, FADH2, and GTP

Question 4

How many membranes does the mitochondria contain and what are they called?

Answer 4

two; inner and outer membrane

Question 5

What is the outer membrane of the mitochondria?

Answer 5

lipid bilayer that is smooth and contains large pores formed by porin proteins

Question 6

What is the inner membrane of the mitochondria?

Answer 6

impermeable lipid bilayer that is densely folded into structures known as cristae

Question 7

Where do cristae extend into?

Answer 7

the matrix

Question 8

What is the matrix of the mitochondria?

Answer 8

innermost space

Question 9

What is the intermembrane space of the mitochondrion?

Answer 9

space between the two membranes that is continuous with the cytoplasm due to the large pores in the outer membrane

Question 10

Where are the enzymes of the PDC and Krebs cycle located?

Answer 10

in the matrix

Question 11

Where are the enzymes of the ETC located?

Answer 11

bound to the inner membrane

Question 12

What are the two goals of ETC/oxidative phosphorylation?

Answer 12

1. reoxidize all of the electron carriers reduced in glycolysis, PDC, and Krebs
2. store energy in the form of ATP

Question 13

What is oxidative phosphorylation?

Answer 13

oxidation of high energy electron carriers NADH and FADH2 coupled to the phosphorylation of ADP to produce ATP

Question 14

What is the source of energy used to drive phosphorylation of ATP?

Answer 14

proton gradient

Question 15

What is the electron transport chain?

Answer 15

group of five electron carriers; three large protein complexes embedded in the inner mitochondrial membrane and two small mobile electron carriers

Question 16

What are the three large protein complexes of the ETC called?

Answer 16

cytochromes due to their heme group

Question 17

What are the names of the five electron carriers in the ETC called in order?

Answer 17

NADH dehydrogenase
ubiquinone
cytochrome C reductase
cytochrome C
cytochrome C oxidase

Question 18

What is ATP synthase?

Answer 18

large protein complex embedded in the inner membrane that contains a proton channel where the proton gradient travels through to produce ATP

Question 19

How many protons are pumped across the membrane by the large protein complexes for each NADH molecule?

Answer 19

10 protons

Question 20

How many protons are required to make one ATP?

Answer 20

4

Question 21

How many ATP are produced for every one molecule of NADH? of FADH2?

Answer 21

NADH = 2.5 ATP
FADH2 = 1.5 ATP

Question 22

What is the glycerol phosphate shuttle?

Answer 22

a pathway that shuttles the electrons from NADH into the inner mitochondrial membrane directly to ubiquinone