Biology Test Biology Biochemistry & Metabolism 3

Question 1

The electron transport chain is located on the:

Accepted Answer

Inner mitochondrial membrane

Answer

The protein complexes of the electron transport chain are embedded in the inner mitochondrial membrane.

Question 2

Which molecule is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen

Answer

Oxygen accepts electrons at Complex IV (cytochrome c oxidase) and combines with protons to form water.

Question 3

Allosteric regulation of an enzyme involves:

Accepted Answer

Binding of a regulator at a site other than the active site

Answer

Allosteric regulators bind at sites distinct from the active site, inducing conformational changes that activate or inhibit the enzyme.

Question 4

During fermentation in human muscle cells, pyruvate is converted to:

Accepted Answer

Lactate

Answer

In anaerobic conditions, human muscle cells convert pyruvate to lactate via lactic acid fermentation to regenerate NAD+.

Question 5

Phospholipids are amphipathic molecules, meaning they have:

Accepted Answer

Both hydrophilic and hydrophobic regions

Answer

Phospholipids have a polar phosphate head (hydrophilic) and two nonpolar fatty acid tails (hydrophobic), driving bilayer formation.

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