Question

In a mammalian cell that was exposed to potassium cyanide (a cytochrome C oxidase inhibitor), you would expect lactate production to be

Select one:

a. Lower than in a healthy cell

b. Higher than in a healthy cell

c. The same as in a healthy cell

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In a mammalian cell that was exposed to potassium cyanide (a cytochrome C oxidase inhibitor), you would expect pyruvate production to be

Select one:

a. Higher than in a healthy cell

b. Lower than in a healthy cell

c. The same as in a healthy cell

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In a mammalian cell that was exposed to potassium cyanide (a cytochrome C oxidase inhibitor), you would expect NADH production to be

Select one:

a. Higher than in a healthy cell

b. Lower than in a healthy cell

c. The same as in a healthy cell

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In a mammalian cell that was exposed to potassium cyanide (a cytochrome C oxidase inhibitor), you would expect O2 consumption to be

Select one:

a. The same as in a healthy cell

b. Higher than in a healthy cell

c. Lower than in a healthy cell

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In a mammalian cell that was exposed to potassium cyanide (a cytochrome C oxidase inhibitor), you would expect CO2 production to be

Select one:

a. The same as in a healthy cell

b. Higher than in a healthy cell

c. Lower than in a healthy cell

Answer 1

1.         Option 1; lower than in a healthy cell

Explanation –

Potassium cyanide (a cytochrome C oxidase inhibitor changes two parameter – a) reduces the activity of cytochrome oxidase (Complex IV) and b) Increase of proton leak in the inner membrane. This suppresses the mitochondrial bioenergetics and inhibits the cell proliferation and increase the release of lactate.

2. Option 3, same as that in a healthy cell

Explanation- Complex IV is reduced when KCN is introduced. However, reducing complex IV do not affect the oxygen concentrations though it is used as a vasodilator in tissues.

3. Option 1; lower than in a healthy cell

Explanation- lowers than in a healthy cell

More than 80% of the oxidase activity of NADH is inhibited by Potassium cyanide and only 20% of the NADH is oxidized.

4. Option 1; lower than in a healthy cell

Explanation - Oxygen interacts with cytochrome c oxidase, since cytochrome c oxidase reduced when exposed to KCN, the oxygen also reduces.