cell respiration

Question 1

how do cells start respiration and what is the main source of fuel for animals?

Answer 1

cells harvest chemical energy stored in molecules to generate ATP

starch

Question 2

path of electrons in energy harvest

Answer 2

glucose —> NADH —> ETC —> oxygen

Question 3

what are the 3 stages of cell respiration?

Answer 3

1) glycolysis

2) pyruvate oxidation and the citric acid cycle

3) oxidative phosphorylation

Question 4

glycolysis

Answer 4

in cytosol, splits glucose into 2 pyruvates

net: ATP, NADH

Question 5

what are the two stages of glycolysis?

Answer 5

energy investment stage: cell uses ATP to phosphorylation glucose

energy payoff stage: energy is produced by substrate level phosphorylation

Question 6

pyruvate oxidation

Answer 6

pyruvate is oxidized into acetyl CoA

acetyl CoA used to make citrate in citric acid cycle

Question 7

citric acid cycle (kreb’s) input and output

Answer 7

(mitochondrial matrix)

inputs: 2 acetyl CoA

outputs: 2 ATP, 6 NADH, 4 CO2, 2 FADH2

Question 8

ETC

Answer 8

in inner membrane of mitochondria

creates protein gradient which powers chemioosmosis

Question 9

chemiosmosis

Answer 9

ATP synthase (ADP+P)

uses energy from H+ gradient

produces 26-28 ATP/glucose

Question 10

how is a proton gradient formed

Answer 10

e- from NADH and FADH2 powers ETC proton pump

Question 11

what are the 2 ways that organisms produce ATP without oxygen

Answer 11

anaerobic respiration: generates ATP using an ETC in absence of oxygen (prokaryotic)

fermentation: generates ATP without an ETC

Question 12

alcohol fermentation

Answer 12

pyruvate is converted to ethanol

Question 13

lactic acid fermentation

Answer 13

pyruvate is reduced directly by NADH to form lactate