Chapter 7 Flashcards
(45 cards)
What are autotrophs?
Organisms that can produce their own organic molecules through photosynthesis.
What are heterotrophs?
Organisms that live on organic compounds produced by other organisms.
What is cellular respiration?
A series of reactions used by organisms to extract energy from organic molecules.
What does oxidation mean in the context of cellular respiration?
Loss of electrons.
What does reduction mean in the context of cellular respiration?
Gain of electrons.
What is dehydrogenation?
The process where lost electrons are accompanied by protons, resulting in the loss of a hydrogen atom.
What role do electrons play in redox reactions?
Electrons carry energy from one molecule to another.
What is the function of NAD+?
An electron carrier that accepts 2 electrons and 1 proton to become NADH.
What is the final electron acceptor in aerobic respiration?
Oxygen (O2).
What is the final electron acceptor in anaerobic respiration?
An inorganic molecule (not O2).
What is the final electron acceptor in fermentation?
An organic molecule.
What is the overall reaction for aerobic respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O +ATP.
Krebs Cycle
What is the free energy release during aerobic respiration?
–686 kcal/mol of glucose.
What are the two mechanisms for ATP synthesis?
- Substrate-level phosphorylation
- Oxidative phosphorylation.
What is glycolysis?
A 10-step biochemical pathway that converts 1 glucose to 2 pyruvate.
Where does glycolysis occur?
In the cytoplasm.
What is produced during glycolysis?
- 2 ATP (net production)
- 2 NADH.
How is NADH recycled for glycolysis to continue?
- Aerobic respiration (using O2)
- Fermentation (when O2 is not available).
What happens to pyruvate in the presence of oxygen?
Pyruvate is oxidized to acetyl-CoA which enters the Krebs cycle.
What enzyme catalyzes the oxidation of pyruvate?
Pyruvate dehydrogenase.
What are the products of pyruvate oxidation?
- 1 CO2
- 1 NADH
- 1 acetyl-CoA.
What is the Krebs cycle?
A series of reactions that oxidizes the acetyl group from pyruvate.
What is produced for each Acetyl-CoA entering the Krebs cycle?
- 2 CO2
- 3 NADH
- 1 FADH2
- 1 ATP.
What is the total yield from glucose after the Krebs cycle?
- 6 CO2
- 4 ATP
- 10 NADH
- 2 FADH2.