LAB 4 - Fermentation (Cider Production)

Question 1

Fermentation

Answer 1

• Anaerobic chemical process by which microorganisms break down glucose into water, alcohol, and carbon dioxide gas
• Is one of the oldest ways that humans have utilised microorganisms

Question 2

Uses of fermentation

Answer 2

• Wine
• Beer
• Bread
• Antibiotics
• Hormones
• Antibodies
• Insulin

Question 3

Which yeast species was investigated in the experiment

Answer 3

Saccharomyces cerevisiae

Question 4

Methylene blue dye

Answer 4

• Able to enter all yeast cells regardless of if they are dead or alive.
• It is oxidised to a colourless compound within live cells, meaning that only dead cells will appear blue.
• Used extensively in the brewing industry to provide a quick estimate of the viability of the brewer’s yeast.

Question 5

The experiment looked at fermentation of ________________ with ______________________

Answer 5

1. Apple Juice
2. Saccharomyces cerevisiae

Question 6

Equation of fermentation

Answer 6

Glucose –> Ethanol + CO2 + 2ATP

Question 7

Compare the energetics of fermentation to aerobic respiration and anaerobic respiration. Which process yields the most ATP and which yields the least

Answer 7

• Aerobic yields 30-32 ATP (most)
• Anaerobic yields 2 ATP
• Fermentation yields 2 ATp (least)

Question 8

What would be another technique that you could use to determine the numbers of viable yeast cells present?

Answer 8

• Plate counting (colony-forming units)
• Flow cytometry