Fermentation, Anaerobic Glycolysis, Cori Cycle

Question 1

What is involved in fermentation?

Answer 1

Glycolysis and fermentation occur in the cytoplasm.

Pyruvate is converted into acetyladehyde and ethanol.

Pyruvate to acetyladehyde:

• The COO- group is removed from pyruvate and so CO2 is released
• Pyruvate decarboxylase is used as an enzyme
• Mg2+ and TPP are used as cofactors

Acetyladehyde to ethanol: reduction reaction

• Alcohol dehydrogenase is used
• NADH + H+ is converted to NAD+ (oxidation)

Question 2

What is anaerobic glycolysis?

Answer 2

• Occurs in the cytoplasm
• Conversion of pyruvate to L-lactate
• This is an redox reaction
• Lactate dehydrogenase is used as the enzyme
• This is also a reduction reaction
• NADH + H+ is converted to NAD+ (oxidation)
• This is important for generating NAD+ for step 6 of glycolysis

Question 3

What is the Cori Cycle?

Answer 3

Athletes:

• Massive amounts of ATP being used over a short period of time
• Muscle contraction coming from breaking down glycogen to make glucose to produce ATP (glycolysis in the muscle cell)
• Producing large amounts of lactate -> exported out the muscles -> into the bloodstream and travels around the body -> ends up at the liver where it gets converted to pyruvate -> undergoes gluconeogenesis to make more glucose

Muscle: ATP is produced by glycolysis for rapid contraction
Liver: ATP is used in synthesis of glucose during recovery