Lecture 4

The plasma membrane allows:

• Everything to pass freely

• Nothing to pass

• Selective transport of molecules

• Only water to pass

Interstitial fluid originates from:

• Mitochondria

• Blood capillaries

• The nucleus

• Golgi apparatus

Which of the following is carried in interstitial fluid?

• Oxygen, glucose, hormones, CO₂

• Only proteins

• Only ions

• Only lipids

Why must the plasma membrane be selective?

• If everything crossed, the cell would lose control

• If nothing crossed, the cell would starve

• Both A and B

• Neither A nor B

Aerobic respiration generates how many ATP per glucose?

• 2

• 4

• ~32

• 38

In aerobic metabolism, which pathway provides the majority of ATP?

• Glycolysis

• Citric acid cycle directly

• Oxidative phosphorylation (ETC + chemiosmosis)

• Fermentation

The citric acid cycle provides ATP mainly by:

• Producing NADH and FADH₂ for the ETC

• Producing large amounts of direct ATP

• Regenerating glucose

• Pumping protons directly

In the absence of oxygen, which pathways stop?

• Glycolysis only

• Pyruvate decarboxylation + Citric acid cycle + ETC

• Glycolysis + ETC

• All energy pathways

Under anaerobic conditions, how many ATP are produced per glucose?

• 0

• 2

• 4

• 6

Which molecule is reduced to regenerate NAD⁺ during anaerobic glycolysis?

• Lactate

• Pyruvate

• FAD

• Glucose