Gaokao Exam Gaokao Biology: Cell Biology and Metabolism 5

Question 1

The P/O ratio in cellular respiration refers to:

Accepted Answer

The number of ATP molecules synthesized per oxygen atom reduced

Answer

The P/O ratio quantifies oxidative phosphorylation efficiency — approximately 2.5 ATP are produced per NADH and 1.5 ATP per FADH₂ oxidized.

Question 2

Which of the following best describes a secondary active transport mechanism?

Accepted Answer

Co-transport using the electrochemical gradient established by primary active transport

Answer

Secondary active transport uses the electrochemical gradient (often Na⁺ gradient created by the Na⁺/K⁺ pump) to co-transport another molecule against its gradient without direct ATP use.

Question 3

In the light-harvesting complex of chloroplasts, energy from absorbed photons is transferred to the reaction center by:

Accepted Answer

Resonance energy transfer between pigment molecules

Answer

Excited electrons in antenna pigment molecules transfer energy via resonance (Förster energy transfer) through successive pigment molecules to the reaction center chlorophyll.

Question 4

Lysosomes are formed by budding from which organelle?

Accepted Answer

Golgi apparatus

Answer

Lysosomes are formed when vesicles containing hydrolytic enzymes bud from the trans face of the Golgi apparatus.

Question 5

The Q10 coefficient in biology measures:

Accepted Answer

The ratio of reaction rate at a temperature T+10°C versus temperature T

Answer

Q10 is the factor by which a biological process rate changes per 10°C temperature increase; most metabolic reactions have a Q10 of 2–3.

Gaokao Exam Practice Test

Gaokao Exam Practice Test

Gaokao Exam Gaokao Biology: Cell Biology and Metabolism 5