Lecture 5-fermentation

Question 1

Process of ethanol fermentation

Answer 1

• glucose converted to 2 pyruvate (glycolysis), thus 2NAD+ are reduced to 2NADH
• 1 Pyruvate converted to acetyladehyde (releasing CO2)
• acetylaldehyde is reduced by NADH (which is oxidized to form NAD+) to form ethanol

Question 1

Lactic Acid fermentation

Answer 1

• glucose converted to 2 pyruvate (glycolysis), thus 2NAD+ are reduced to 2NADH
• 1 Pyruvate converted to lactate (catalyzed by lactate dehydrogenase) which is reduced by NADH (NADH is then oxidized to NAD+)

Question 2

Why is the REDOX important between NADH and NAD+ in fermentation

Answer 2

by oxidizing NADH to form NAD+ we can regenerate NAD+, which is necessary for glycolysis

Question 3

Where does lactic acid fermentation occur

Answer 3

bacteria converts sugar into lactic acid to obtain energy

Question 4

Where does ethanol fermentation occur

Answer 4

yeast (fungi) converts sugar into alcohol to obtain energy

Question 5

Where does fermentation in general occur

Answer 5

the cytoplasm of micro-organisms, such as bacteria or fungi