Exam 2 Microbial Metabolism PT 3

Question 1

Cellular Respiration

Answer 1

Breakdown of CO2 and H2O

Aerobic- final electron acceptor O2
Anaerobic- final electron acceptor not O2- less energy

Question 2

Stages and prokaryotes and eukaryotes of Glucose Catabolism

Answer 2

Stage 1.) Glycolysis
- Eukaryote: Cytoplasm
-Prokaryote: Cytoplasm

Stage 2.) Synthesis of Acetyl-CoA
- Eukaryote: Mitochondrial matrix
- Prokaryote: Cytoplasm

Stage 3.) Krebs Cycle:
- Eukaryote: Mitochondrial Matrix
- Prokaryote: Cytoplasm

Stage 4.) Electron Transport Chain:
- Eukaryote: Mitochondrial inner membrane
- Prokaryote: Plasma Membrane

Question 3

Aerobic Cellular Respiration of Glucose

Answer 3

A giant redox reaction

Glucose + oxygen
( Energy is released )
Carbon dioxide + water

Question 4

Stage 1.) Glycolysis

Answer 4

(Splitting sugars)
-Redox reaction
-Substrate level phosphorylation
Generates: 2 NADH + 2 ATP + 2 Pyruvic acid

Question 5

Stage 2.) Synthesis of Acetyl-CoA

Answer 5

Redox reaction
Decarboxylation
Generates: 2 NADH, 2 CO 2 and 2 Acetyl CoA

Question 6

Stage 3.) Krebs Cycle

Answer 6

Redox Reaction
Decarboxylatoin –> CO2
Substrate level phosphorylation –> 2 ATP
Generates: 6 NADH, 2 FADH, 2 ATP and 4 CO2

Question 7

Stage 4.) Electron Transport Chain

Answer 7

1st step. electrons are removed from NADH and FADH2.
2nd step. hydrogen ions are transported across membrane.
3rd step. ADP changed to ATP when hydrogen ions flow through ATP synthase.
4th step. water formed when oxygen picks up electrons and H+ ions.

Question 8

How much ATP is generated during prokaryotic and eukaryotic respiration

Answer 8

Prokaryotic: 38 ATP
Eukaryotic: 36 ATP

Question 9

Why is prokaryotic and eukaryotic respiration different

Answer 9

Cellular respiration occurs in the cytoplasm and the cell membrane of prokaryotes. This is in contrast to eukaryotes, where most of the energy production occurs in the mitochondria

Question 10

Fermenation

Answer 10

Partical oxidation (breakdown) of glucose
- O2 is not required
- produces organic waste products such as lactic acid, ethanol, and alcohol
- Recycles NAD
-Redox reaction
-Glycolysis is the only source of ATP

Question 11

What happens during lactic acid and alcohol fermentation

Answer 11

Lactic Acid: Pyruic acid is reduced to lactic acid. Bacteria!! milk –> cheese or yogurt

Alcohol: Acetyladehyde is reduced to ethanol.
Yeast! grape juice –> wine