Mitochondria and Oxidative Phosphorylation Flashcards Preview

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Flashcards in Mitochondria and Oxidative Phosphorylation Deck (24)
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1
Q

How many ATP does one NADH produce in the ETC?

A

3

2
Q

How many ATP does one FADH2 produce in the ETC?

A

2

3
Q

How are mitochondria inherited?

A

Maternally

4
Q

What are 5 pieces of evidence supporting the endosymbiosis theory?

A

Mitochondria only arise from preexisting mitochondria.
Mitochondria have their own genome which resembles prokaryotes.
Mitochondria have their own protein synthesising machinery which resembles prokaryotes.
The first amino acid of their transcripts is fMet which is the same as in bacteria.
A number of antibiotics bock protein synthesis in mitochondria.

5
Q

What is the route for electrons in the ETC?

A

NADH dehydrogenase complex –> ubiquinone/coenzyme Q –> cytochrome bc1 complex –> cytochrome C –> cytochrome oxidase –> oxygen

6
Q

What allows the flow of the electrons in a logical order?

A

The fact that each unit in the chain has a higher affinity for electrons/has a higher redox potential (more positive)

7
Q

What is the redox potential?

A

The ability of a redox couple to accept or donate electrons.

8
Q

What does a negative redox potential suggest?

A

An ability to donate

9
Q

What does a positive redox potential suggest?

A

Ability to accept

10
Q

Which is the membrane bound part and which projects into the mitochondrial space of ATP synthase, F0 or F1?

A

F0 - membrane bound, F1 - projects.

11
Q

Which subunit acts as an axle in F1?

A

Gamma

12
Q

Which subunit undergoes structural changes due to gamma axle rotating?

A

Beta

13
Q

Why does FADH2 make less ATP?

A

Because it passes its electrons directly to ubiquinone

14
Q

Name 5 metabolic poisons

A

Cyanide, carbon monoxide, malonate, oligomycin and dinitrophenol

15
Q

Explain the mechanism of cyanide

A

Binds with high affinity to the ferric (Fe3+) form of the ferric group of cytochrome oxidase and inhibits it, blocking the flow of electrons

16
Q

Explain the mechanism of carbon monoxide

A

Binds to haemoglobin stronger than oxygen so oxygen is not supplied to the body

17
Q

Explain the mechanism of malonate

A

Resembles succinate so acts as a competitive inhibitor and slows down the flow of electrons from succinate to ubiquinone by inhibiting oxidation of succinate to fumarate

18
Q

Explain the mechanism of oligomycin

A

Binds to the stalk (gamma subunit) of ATP synthase and blocks the flow of protons through the enzyme

19
Q

Explain the mechanism of dinitrophenol

A

Induces weight loss by transporting protons across the mitochondrial membrane thereby uncoupling oxidative phosphorylation from ATP production and therefore increasing metabolic rate and body temperature

20
Q

Which metabolic poison uncouples ATP production from oxidative phosphorylation?

A

Dinitrophenol

21
Q

Which metabolic poison binds to the stalk (gamma subunit) of ATP synthase?

A

Oligomycin

22
Q

Which metabolic poison inhibits succinate dehydrogenase?

A

Malonate

23
Q

Which metabolic poison binds to haemoglobin?

A

Carbon monoxide

24
Q

Which metabolic poison binds cytochrome oxidase and inhibits it?

A

Cyanide