AP BIOLOGY

CELL RESPIRATION

GLYCOLYSIS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
If oxygen is not present what process will occur in yeast cells?
A
Alcoholic fermentation
B
Respiration
C
Photosynthesis
D
Lactic acid fermentation
Explanation: 

Detailed explanation-1: -When yeast cells are kept in an anaerobic environment (i.e., without oxygen), they switch to alcoholic fermentation to generate usable energy from food. Like lactic acid fermentation, alcoholic fermentation generates NAD+ so that glycolysis can continue to produce ATP.

Detailed explanation-2: -Fermentation does not require oxygen and is therefore anaerobic. Fermentation will replenish NAD+ from the NADH + H+ produced in glycolysis. One type of fermentation is alcohol fermentation.

Detailed explanation-3: -In the presence of oxygen, yeast undergo aerobic respiration and convert carbohydrates (sugar source) into carbon dioxide and water. In the absence of oxygen, yeasts undergo fermentation and convert carbohydrates into carbon dioxide and alcohol (Figure 2).

Detailed explanation-4: -Anaerobic and aerobic respiration share the glycolysis pathway. If oxygen is not present, fermentation may take place, producing lactic acid or ethyl alcohol and carbon dioxide. Products of fermentation still contain chemical energy, and are used widely to make foods and fuels.

There is 1 question to complete.