Study Guide

• why does increasing substrate concentration/decreasing product concentration favor a forward reaction?

  decreases equilibrium constant, negative delta G
• in lactic acid fermentation, what is oxidized and what is reduced?

  NADH is oxidized to NAD+

  pyruvate is reduced to lactic acid
• in alcohol fermentation, what is oxidized and what is reduced?

  NADH is oxidized to NAD+

  acetylaldehyde is reduced to ethanol
• in aerobic respiration/after glycolysis, what is oxidized and what is reduced?

  pyruvate is oxidized to acetyl-coA

  NAD+ is reduced to NADH
• good electron donors have a more negative potential
• a negative change in PE is favorable, donor potential will be less +
• fermentation: energy yielding process where organic molecules serve as electron donors and acceptors
• what is an electron donor in fermentation?

  NADH
• what are terminal electron acceptors in fermentation?

  pyruvate and acetylaldehyde
• what causes low alcohol content in beer fermentation?

  lactic acid bacteria contamination
• what causes bitter apple taste in beer fermentation?

  high ethanol
• what causes spicy taste in beer fermentation?

  high sugar content
• in substrate level phosphorylation, where is the phosphate group transferred from?

  an organic molecules
• what causes bubbly cheese?

  contaminant that results in heterofermentation
• homofermentation pathway:

  1. glycolysis produced pyruvate
  2. pyruvate is reduced to form lactate
• heterofermentation pathway:

  1. glucose forms GAP and acetyl phosphate
  2. GAP produces pyruvate and lactate
  3. acetyl phosphate produces ethanol
• what is the result of lactic acid being the major product in kimchi fermentation?

  the last step is homofermentation
• what substrates are added first in chocolate fermentation?

  lactic acid bacteria and yeast
• when is peak acetic acid concentration in chocolate fermentation?

  day 3
• when is peak temperature in chocolate fermentation?

  day 4
• when are spore-formers added in chocolate fermentation?

  day 4