LEC 10 Flashcards
Citric Acid Cycle & Electron Transport System
Where does the citric acid cycle happen?
in the inner membrane region
For each glucose (started with in Step #1), the citric acid cycle happens _____
One for each ____ ____ that was formed by the ______ of glucose
- twice
- acetyl group
- catabolism
Stage #3 - Citric Acid Cycle Step 1 (2)
Acetyl CoA delivers acetyl to citric acid cycle
- Acetyl combines with oxaloacetate to make citric acid.
Stage #3 - Citric Acid Cycle Step 2 (3)
Citric acid is metabolized
1. A carbon is removed, combines with O2 to make CO2.
2. NAD+ picks up 1 hydrogen and 2 electrons to NADH
3. Remaining molecule is α-ketoglutarate
Stage #3 - Citric Acid Cycle Step 3 (4)
α-ketoglutarate is metabolized
1. A carbon is removed, combines with O2 to make CO2.
2. NAD+ picks up 1 hydrogen and 2 electrons to make NADH
3. ADP to ATP
4. Remaining molecule is succinate
Stage #3 - Citric Acid Cycle Step 4 (2)
Succinate is metabolized
1. FAD picks up 2 hydrogen and 2 electrons to make FADH2
2. Remaining molecule is fumarate
Stage #3 - Citric Acid Cycle Step 5 (2)
Fumarate is metabolized
1. NAD+ picks up 1 hydrogen and 2 electrons to make NADH
2. Remaining molecule is oxaloacetate (which starts the next cycle)
oxaloacetate
Combines with Acetyl to make citric acid
citric acid (2)
oxaloacetate + Acetyl
metabolized in step 2 of citric acid cycle
α-ketoglutarate (2)
- Left over in step 2 of citric acid cycle
- metabolized in step 3
succinate (2)
- Left over in step 3 of citric acid cycle
- metabolized in step 4
fumarate (2)
- Left over in step 4 of citric acid cycle
- metabolized in step 5
Coenzyme FAD full form
Flavin adenine dinucleotide
Becomes FADH2 by picking up: (2)
- Two (2) high energy H+ ions
- Two (2) electrons
What is FADH+ used for?
carry these high energy ions to the final stage of energy production
Summary: Stage #3 – Citric Acid Cycle ATP
2 molecules produced by substrate level phosphorylation
Summary: Stage #3 – Citric Acid Cycle Coenzyme activity (2)
- Six NAD+ molecules pick-up 1 hydrogen and 2 electrons each to become 6 molecules of NADH (Go to Stage #4)
- Two FAD molecules pick-up 2 hydrogen and 2 electrons each to become 2 molecules of FADH2 (Go to Stage #4)
Summary: Stage #3 – Citric Acid Cycle What’s left?
- Four molecules of CO2 (waste)
- Two molecules of oxaloacetate (used to start the next cycle)
What molecule delivers acetyl to the citric acid cycle?
Acetyl CoA
Acetyl combines with ________ to form citric acid.
oxaloacetate
What happens to citric acid in the citric acid cycle? (4)
- A carbon is removed from citric acid
- combines with O₂ to form CO₂
- NAD+ picks up 1 hydrogen and 2 electrons to form NADH
- The remaining molecule is called α-ketoglutarate.
What is the next molecule formed after citric acid is metabolized?
α-ketoglutarate.