fermentation

Question 1

Fermentation

Answer 1

• metabolic process that converts sugars to acids, gases or alcohol.
• alternate pathway AFTER STAGE 1 (Glycolysis)
• happens when there’s no oxygen or when you can’t get oxygen fast enough…
• can do in anerobic environment

Question 2

how is ATP made in fermentation vs in respiration?

Answer 2

Fermentation
Cell makes ALL of its ATP by substrate level phosphorylation

Respiration
ATP made in Stage 1, 3, 4 i.e. Cell makes MOST of its ATP by oxidative phosphorylation

Question 3

why will Pyruvate not be able to continue in cellular respiration in fermentation

Answer 3

e.g. Cannot
* enter the mitochondria
* undergo acetyl co-A synthesis
* Citric acid cycle

Most likely reason is lack of terminal electron acceptor O2

Question 4

why does fermentation produce less energy?

Answer 4

results in waste products ethanol and lactic acid
– not all the carbons have been oxidized
– therefore energy in the reduced carbon bonds is not utilized

Question 5

glycolysis and fermentation

Answer 5

during fermentation, NADH donates electrons to re-generate NAD+.
Now, NAD+ can return to glycolysis to pick up more electrons.
wow energy

Question 6

oxidation of carbon in fermentation vs cellular respiration and effect on energy

Answer 6

In cellular respiration (stages 1 – 4 inclusive):
- All 6 Carbon atoms in Glucose are completely oxidized to CO2
- Oxidized C atoms discarded as CO2 waste

Fermentation:
- No net oxidation of C.
- Electrons removed from some C atoms
and returned to others.
- The products of fermentation are waste products

Question 7

difference in ATP synthesis in cellular respiration vs fermentation

Answer 7

respiration
- More ATP can be synthesized IF the cell can complete all 4 stages of cellular respiration

fermentation
- Much less (««) ATP
- If a cell can only complete Stage 1 (glycolysis) and fermentation