fermentation and aerobic respiration

fermentation lacks…

an electron transport chain.

step 1 of fermentation is…

Glycolysis

what are the two fermentation pathways?

lactic acid and alcoholic.

describe lactic acid fermentation.

pyruvate is converted into lactic acid. in doing so, NADH drops off its electrons and turns back into NAD+.

describe alcoholic fermentation.

pyruvate —> ethanol + CO2. this also turns NADH to NAD+. used by yeasts.

what is the first step of fermentation?

glycolysis—produces 2 pyruvates and fills up electron carrier molecules (NAD+).

what is the second step of fermentation?

glycolysis runs out of available NAD+, so pyruvate takes electrons from NADH, which turns them back to NAD+ so glycolysis can loop again and produce 2 more ATP.

fermentation does not involve mitochondria. instead it occurs in the…

cytoplasm.

anaerobic respiration’s first step is…

glycolysis

what happens after glycolysis in anaerobic respiration?

the krebs/citric acid cycle. pyruvate broken up, releasing waste gasses and loading up electron carriers.

step 3 of anaerobic respiration

ETC—electrons flow down protein chain and pump protons + power ATP synthase turbine.

what is the 4th and final step of anaerobic respiration?

like aerobic respiration, it involves an electron acceptor after the molecules enter the ETC to fuel ATP synthesis. However, it does not use oxygen.

what are the common chemical alternatives to oxygen used in anaerobic respiration?

sulfate, nitrate, and CO2.