4.1

Question 1

Recall Photosynth.

IMAGE

Answer 1

• Products of photosynthesis (sugar and O2) are used for energy releasing reactions in aerobic cells
• Potential energy extracted form food molecules via oxidation are used to synthesize ATP
• Chem. energy stored in ATP can be used and released by cells
• When O2 is unavailable, anaerobic cells have an alternate way to release energy from food

Question 2

Aerobic Cellular Respiration

Answer 2

• Process that extracts energy from food in the presence of O2
• Energy from ADP + Pi is used to synthesize ATP
• Takes place in most Eukaryotes and some prokaryotes

Question 3

Obligated aerobes, anaerobes, and Facultative Anaerobes

Answer 3

Obligated aerobes:
-Reqiures O2 to survive
Ex. Humans

Obligated anaerobes:
-Cannot survive in an environment with O2

Facultative Anaerobes:
-Can survive with or without O2
Ex. yeast and E.coli

Question 4

4 stages of Aerobic Cellular Respiration

Answer 4

Each stage involves the transfer of free energy in one way or another

1. Substrate-level Phosphorlylation

• Forms ATP directly through enzymatic catalyzed rxns
• Through transfer of phosphate group to ADP molecule

2. Oxidative Phosporylation
   - Forms ATP indirectly
   -Via series of redox rxns
   -Involves a final electron acceptor

In aerobic cellular respiration, O2 is the final electron accepter

Question 5

Glycolysis

Answer 5

• Occurs in cytosol
• Enzyme splits glucose into 2 pyruvate molecules
• 2 ATP and NADH are synthesized
• Via substrate-level phosphorylation

Question 6

2. Pyruvate Oxidation

Answer 6

• Occurs in mitochondria
• Each pyruvate is oxidized
• Produces CO2, NADH, Acetl-CoA

Acetyl-CoA —> (acytle group + Coenzyme A)

Question 7

Citric Acid Cycle

Answer 7

• Occurs in mitochondria
• Acetyl-CoA enters metabolic cycle, actyl group is oxidized into CO2
• ATP, NADH, and FADH2 are synthesized
• Via substrate level phopsorlylation

Question 8

4. Electron transport/Oxidative phosphorylation

Answer 8

• Occurs in mitochondria
• NADH, FADH2, are oxidized
• High energy electrons and H2 are passed from oxidizing agent, until is reaches O2 to forms H2O
• Free energy is released
• Used to to make ATP via oxidative phosphorylation

Question 9

The Mitochondria

IMAGE

Answer 9

• Organelle involved in the production of ATP
• 2 Membranes (inner and outer)
• Intermembrane space is the
  space b /w the outer and inner
• Matrix is the interior aqueous
  env.

Question 10

Prokaryotes and Aerobic Cellular Respiration

Answer 10

• Some prokaryotes undergo aerobic cellular respiration
• Glycolysis, Pyruvate Oxidation, and the Citric Acid Cycle
  occur in the cytosol
• Electron Transport occurs on internal membranes

Question 11

Anaerobic Pathways

Answer 11

1. Anaerobic Respiration
   - Similar to aerobic respirationw ith series of steps, but uses an inorganic molecule as final electron accepter
2. Fermentation
   - Does not use electron transport system

-Uses organic molecule as final electron acceptor

Both are catabolic processes

Releases free energy (less than aerobic) to synth. ATP