5.5 Anaerobic respiration

Question 1

what is anaerobic respiration?

Answer 1

partial breakdown of hexose sugars (glucose) in oxygen- deprived conditions to produce a limited ATP yield

Question 2

what happens during anaerobic respiration in animals?

Answer 2

• only glycolysis continues
  pyruvate + NADH –> oxidised NAD(+) (for further glycolysis) + latate

Question 3

how does pyruvate act in anaerobic respiration?

Answer 3

as a hydrogen acceptor (accpets H from NADH)

Question 4

what happens to the lactate produced in anaerobic respiration?

Answer 4

• transported to liver in bloodstream
• oxidised to pyruvate by lactate dehydrogenase
• involves conversion of NAD to NADH
• enters link reaction in liver cells or is converted to glycogen

Question 5

how does lactate affact muscle contraction in mammals?

Answer 5

acidic, so decreases pH
results in muscle fatigue

Question 6

what happens during anaerobic respiration in some microorganisms like yeast and some plant cells

Answer 6

only glycolgysis continues
pyruvate is decarboxylated to form ethanal
ethanal is reduced to ethanol using NADH to produced oxidised NAD for glycolysis

Question 7

draw a flowchart to show how ethanol is produced during anaerobic respiration

Answer 7

Question 8

what is the advantage of producing ethanol/lactate during anaerobic respiration?

Answer 8

converts NADH back int NAD so glycolysis can continue

Question 9

what is the disadvantage of producing ethanol during anaerobic respiration?

Answer 9

dissolves cell membranes so cells die when conc is above 12%

Question 10

compare the atp yields per molecule of hexose sugar from aerobic and anaerobic respiration

Answer 10

aerobic ~ 38 in ideal conditions
aerobic ~ 2 from glycolysis

Question 11

explain the principle behind using a respirometer

Answer 11

pressure chnages in the boiling tube due to CO2 production or O2 consumption and cause a drop of coloured liquid to move

Question 12

what liquid absorbs CO2

Answer 12

sodium hydroxide/soda lime