FERMENTATION

Question 1

Fermentation enables aerobic (O2 requiring) species to make ___ under _____ conditions

Answer 1

ATP under anaerobic conditions
-It enables your cells to continue using glycolysis to make ATP molecules temporarily under low O2 conditions

Question 2

During intense physical activity, your muscle cells make ATP by ___ when O2 levels are insufficient to support ATP synthesis in mitochondria by cellular respiration

Answer 2

Glycolysis

Question 3

There are ___ types of fermentation in nature

Answer 3

> 12

Question 4

Fermentation converts the reduced, energy rich, NADH molecule to its-

Answer 4

Oxidized NAD+ form required by glycolysis

Question 5

NAD+ is a substrate for

Answer 5

Triose phosphate dehydrogenase
-Converts NAD+ to NADH during the energy payoff reactions of glycolysis
-Glycolysis stops without NAD+

Question 6

Lactic acid fermentation

Answer 6

Enables your cells to temporarily produce ATP molecules by glycolysis for 1-3 minutes under low O2 conditions
-This reaction is critical for human cell types with consistently high energy demands

Question 7

Lactic acid fermentation process

Answer 7

1. Lactate dehydrogenase (LDH) converts -
2. NADH to NAD+
3. pyruvate to lactate (lactic acid)

Question 8

Human cell types produce distinct forms of lactate dehydrogenase enzymes called

Answer 8

Isozymes (enzymes with an identical function and different structures)

Question 9

The body recycles and reuses the energy rich, 3 carbon, _____ molecules produced by ____

Answer 9

Lactate molecules produced by LDH

Question 10

Lactate made in muscle cells is exported and transported to-

Answer 10

-Oxygenated cells that convert it to pyruvate, which enters cellular respiration
-Liver cells that sue the Cori Cycle to convert two lactate molecules to glucose

Question 11

Lactic acid fermentation cannot satisfy the long term energetic needs of your cells due to its-

Answer 11

Relatively low efficiency of energy transfer (2-3%)
-The efficiency of cellular respiration is ~35-40%
~38 ATP produces from 1 glucose via cellular respiration
2 ATP produced from 1 glucose via lactic acid fermentation

Question 12

Saccharomyces Cerevisiae

Answer 12

-Baker’s yeast/brewer’s yeast
-Single cell fungus that performs alcohol fermentation (ethanol)
-Can perform fermentation for extended periods

Question 13

Saccharomyces cerevisiae requires 2 enzymes to perform alcohol fermentation

Answer 13

-Pyruvate decarboxylase converts pyruvate to 2-acetylaldehyde (a CO2 molecule is released from pyruvate)
-Alcohol dehydrogenase converts NADH to NAD+, 2-acetylaldehyde to ethanol

Question 14

Humans have used baker’s yeast and alcohol fermentation for eons to produce safe drinking water

Answer 14

-Pathogenic fecal bacteria contaminated our ancestors’ drinking water
-Ethanol molecules in beer and wine destroy many pathogenic microbes
-Consuming beer or wine was much safer for our ancestors than consuming water