citric acid cycle and respiratory chain Flashcards
Outline the citric acid cycle
What are the other names for the citric acid cycle?
- Krebs cycle
- Tricarboxcylic acid cycle
Where does the citric acid cycle take place?
In the matrix of the mitochondria
What is FAD?
- Flavin adenine dinucleotide
- Formed from vitamin riboflavin (vitamin B2)
What is caused by deficiency of vitamin riboflavin?
- Lesions of the mucous membranes:
- Cracked, sore lips and corners of the mouth
- Similar in genital regions
- Tongue swollen, tender and magenta
Describe the translocation and decarboxylation of pyruvate
- Moves from the cytoplasm to the matrix of the mitochondria
- Combines with CoA
- Donates to NAD+, converting it to NADH
- Gives off a CO2 molecule
- Produces Acetyl Co A which becomes the acyl unit and CoA
Which vitamin is contained in CoA?
Vitamin B5: Pantothenic acid
Where does the repiratory chain happen?
Macromolecular assemblies in the inner mitochondrial membrane
What are the complexes in the respiratory chain?
- Complex I: NADH cytochrome Q reductase
- Complex II: Succinate coenzyme Q oxidoreductase
- Complex III: Cytochrome reductase
- Complex IV: Cytochrome C oxidase
Where does NADH feed into the respiratory chain?
To complex I (NADH cytochrome Q reductase)
Where does FADH2 feed into the respiratory chain?
(in flavoproteins ) To complex II (succinate coenzyme Q oxidoreductase)
Which of the complexes in the respiratory chain can generate proton gradients?
Complex I and complex II
Which of the complexes is lipid solubule?
Complex II (succinate coenzyme Q oxidoreductase)
How many proteins are present in complex II?
4
Describe electron transfers at complex II
It can undergo 1 or 2 electron transfers
2= ubiquinone
1= semiquinone
How many proteins are present in complex I?
34
NADH cytochrome C reductase
How many proteins are present in Cyctochrome Reductase?
10
Where is the proton concentration highest in the mitochondria?
In the intermembrane space
What is used to drive ATP synthesis?
Caused by the movement of e- down the electron chain which generates a H+ ion (pH) gradient across the inner mitochondrial membrane
How many molecules of ATP are generated from one NADH molecule?
3
How many molecules of ATP are generated from one molecule of FADH2
2
How many molecules of ATP are made in glycolysis and what is the net amount?
Makes 4 ATP and the net amount is 2
How many molecules of ATP are made per molecule of glucose (net)
4
Describe the number of ATP made after mitochondrial oxidative phosphorylation
- 4 from ATP production
- 3-5 ATP from the 2 cytoplasmic NADH
- 20 ATP from the 8 mitochondrial NADH
- 3 ATP from the 2 FADH2
Total = 30-32 ATP
Which chemical agents are targets for the respiratory chain?
- Rotenone- insecticide, piscicide
- Antimycin A - Antibiotic
- Cyanide and carbon monoxide block the final step by which hydrogen combines with oxygen
