The Basics
What does “anaerobic” mean?
“Without oxygen.”
What molecule does glycolysis start with?
Glucose
What is the “energy currency” of the cell?
ATP
What is the end product of lactic acid fermentation?
Lactic acid (lactate)
What food is made using yeast fermentation?
Bread (and also beer or wine)
What is the main purpose of fermentation in cells?
To regenerate NAD⁺ so that glycolysis can continue
What is glucose split into during glycolysis?
Two molecules of pyruvate
What molecule carries electrons during glycolysis?
NAD⁺ / NADH
What are the end products of alcoholic fermentation?
Ethanol and carbon dioxide
What causes the bubbles in bread dough?
CO₂ from yeast fermentation
Which process comes right before fermentation?
Glycolysis
What are the two main types of fermentation?
Lactic acid fermentation and alcoholic fermentation
How many NADH molecules are made per glucose in glycolysis?
2 NADH
Which organisms commonly perform alcoholic fermentation?
Yeasts, certain bacteria, and some plants
What food is made using lactic acid fermentation by bacteria?
Yogurt, cheese, or sauerkraut
How many ATP molecules are produced per glucose in anaerobic respiration?
2 ATP
What happens to pyruvate during fermentation?
It’s converted into lactic acid or ethanol + CO₂.
What happens to NADH during fermentation?
It is oxidized to regenerate NAD⁺
Why do your muscles sometimes perform lactic acid fermentation?
When oxygen is low during intense exercise
Why do athletes sometimes feel a “burn” in their muscles?
Lactic acid buildup during anaerobic respiration
What type of cells can perform fermentation?
Many, including bacteria, yeast, and muscle cells.
Why do cells need fermentation to keep making energy when there’s no oxygen?
NAD⁺ would run out, and glycolysis needs NAD⁺ to keep making ATP.
Why does anaerobic respiration produce less ATP than aerobic respiration?
Because the electron transport chain (which makes lots of ATP) doesn’t work without oxygen.
Which type of fermentation releases gas bubbles?
Alcoholic fermentation (CO₂ is produced)
In which industry is alcoholic fermentation most important?
Brewing and winemaking industries