Lecture 15: Cellular Energy Harvest

Question 1

what are the six types of trophic levels?

Answer 1

Energy
- Phototrophs: light (plants, algae)
- Chemotrophs: chemical compound (animal, plants)

Carbon
- Autotrophs: inorganic carbon (plants, algae)
- Heterotrophs: organic source

Electrons
- Lithotrophs: inorganic compound (H2S)
- Organotrophs: organic compound (glucose)

Question 2

Glycolysis

Answer 2

• takes place in the cytosol
• converts glucose to pyruvate
• can function under aerobic or anaerboic
• results in 2 pyruvate, 2 ATP (net), 2 NADH

Question 3

Pyruvate Oxidation

Answer 3

• Pyruvate is converted to acetyl CoA
• Energy is captured by reduction of NAD+ to NADPH
• results in 2 acetyl coA, 2 Co2, 2 NADH

Eukaryotes (in the mitochondrial matrix)
Bacteria (in the cell membrane)

Question 4

Citric Acid Cycle

Answer 4

• runs twice for each glucose precurser (2 acetlyl coA)
• occur in the mitochondrial matrix
• results in 4 Co2, 2 CoA, 6 NADH, 2 FADH, 2 ATP

Question 5

Ceullar locations for energy pathways (eukaryotes vs prokaryotes)

Answer 5

Eukaryotes
- External to Mitochondrion: Glycolysis & Fermentation
- Internal mitochondrion: ETC (inner membrane) & Citric acid cycle and pyruvate oxidation (matrix)

Prokaryotes
- In cytoplasm: glycolysis, fermentation, citric acid cycle
- On plasma membrane: Pyruvate oxidation & ETC