Cellular respiration: anaerobic respiration

Question 1

when does anaerobic respiration occur? explain why

Answer 1

• when o2 is not enough, only glycolysis can still occur
• release only small amt of energy (2 ATP)
• anaerobic respiration does not require o2

Question 2

what is the purpose of fermentation?

Answer 2

regenerate NAD+ from NADH produced in glycolysis so that glycolysis can continuously produce 2 ATP to sustain activity

Question 3

write down the following for lactate fermentation (in mammalian muscles):

1. chemical equation
2. word equation
3. final hydrogen/electron acceptor

Answer 3

1. glucose–> lactic acid + small amt of energy
2. c6h12o6—> 2 c3h6o3 _ small amt of ATP
3. pyruvate

Question 4

write down the following for alcoholic fermentation (in plants and yeast):

1. chemical equation
2. word equation
3. final hydrogen/electron acceptor

Answer 4

1. glucose –> ethanol + carbon dioxide + small amount of energy
2. c6h12o2–> 2 c2h5oh + 2 co2 + small amount of ATP
3. ethanal

Question 5

state the differences between aerobic respiration and anaerobic respiration

Answer 5

aerobic respiration vs anaerobic respiration
reactants: glucose + o2 glucose
products: co2 + h2o lactate, ethanol + o2
location: cytoplasm and cytoplasm
mitochondria
stages: glycolysis, LR, krebs Glycolysis, fermentation
cycle, OP

Question 6

what is the effect of lactic acid and what happens to it?

Answer 6

effect: accumulation causes muscular fatigue, pains and cramps
fate of lactic acid: transported via bloodstream to liver where some of it is oxidised by oxygen to form co2 and h2o which releases energy to convert the rest of lactic acid to pyruvate

Question 7

why does breathing rate remain high?

Answer 7

oxygen debt (oxygen needed to break down lactic acid) incurred so breathing rate continues to be high to supply o2 needed to repay o2 debt