anaerobic fermentation

Question 1

What is anaerobic fermentation?

Answer 1

Anaerobic fermentation involves breakdown of glucose and ATP production via glycolysis in the absence of oxygen.

Question 2

What does anaerobic fermentation allow for?

Answer 2

It allows for the replenishment of NAD+ for continued use in glycolysis

Question 3

What is there a lack of in anaerobic conditions?

Answer 3

There is a lack of oxygen in anaerobic conditions

Question 4

What does a lack of oxygen in cellular respiration mean?

Answer 4

It means that protons and electrons can’t bond with oxygen to form water. Without the electron transport chain, loaded coenzymes such as NADH and FADH2 cannot drop off their electrons and be converted back to unloaded NAD+ and FAD, which are required as inputs for the Krebs cycle.

Question 5

what happens as a result of the oxygen dependent pathways being disrupted under anaerobic conditions?

Answer 5

as a result, oxygen dependent pathways of the krebs cycle and the electron transport chain are disruspted under anaerobic conditions and this key source of ATP is lost.

Question 6

how can cells still live off the energy from this anaerobic pathway?

Answer 6

because glycolysis still produces a little bit of ATP which cells can live off

Question 7

how does anaerobic fermentation work in animals?

Answer 7

in animals, anaerobic fermentation involves the conversion of pyruvate to lactic acid.

Question 8

when does the NAD+ regeneration stage happen in both yeast and animals and where does it occur?

Answer 8

after glycolysis in the cytosol of the cell, just like glycolysis

Question 9

what does the breakdown of pyruvate into lactic acid do?

Answer 9

cycles back NADH to NAD+ for reuse in glycolysis.

Question 10

why should lactic acid not accumulate?

Answer 10

it shouldnt accumulate indefinetly, as it lower ph of our cells and blood.

Question 11

how do our cells fix this problem of lactic acid accumulating?

Answer 11

once oxygen is present again, lactic acid is metabolised back into pyruvate and used for aerobic cellular respiration.

Question 12

inputs for lactic acid fermentation?

Answer 12

pyruvate, NADH

Question 13

outputs for lactic acid fermentation?

Answer 13

lactate, NAD+

Question 14

what happens in anaerobic fermentation in yeasts?

Answer 14

it also involves glycolysis, but instead pyruvate is converted into ethanol and CO2. also known as ethanol fermentation

Question 15

what are yeasts unable to do and what does it result in?

Answer 15

they are unable to metabolise ethanol into any useful product, so ethanol diffuses out of cells.

Question 16

what is a drawback of ethanol fermentation accumulating in cells

Answer 16

ethanol concentration of a yeast in a confined environment can eventually accumulate to toxic levels.

Question 17

location and inputs of ethanol fermentation?

Answer 17

location is cytosol

inputs: pyruvate, NADH

outputs: ethanol, CO2, NAD+

Question 18

differences between aerobic cellular respiration and anaerobic fermentation?

Answer 18

1.) Aerobic involves glycolysis, krebs and ETC, where Anaerobic involves glycolysis, lactic acid in animals or alcoholic fermentation in yeasts

2.) Aerobic happens in cytosol and mitochondria, anaerobic happens in cytosol only

3.) aerobic has an input of oxygen, anaerobic only has glucose

4.) aerobic has a higher atp efficiency (30 or 32 atp per glucose molecule) whereas anaerobic has lower atp efficiency (2 ATP per glucose molecule)

5.) aerobic is slow and anaerobic is faster

6.) Aerobic can continue indefinetly, whereas anaerobic cannot continue indefinetly, due to toxic build up of lactic acid or ethanol.