Practice Questions

Cell wall thickness is unrelated to the fluidity of the plasma membrane.

Carbohydrate chains are attached to proteins/lipids only on the non-cytosolic side of the membrane.

Passive transport relies on kinetic energy (gradient), while active transport requires metabolic energy (ATP).

Facilitated diffusion requires either channel or carrier proteins to assist polar molecules.

The two hydrocarbon chains (fatty acids) are non-polar and hydrophobic.

The phospholipid bilayer provides the fundamental hydrophobic barrier essential for cellular compartmentalization.

By measuring the surface area of extracted lipids, they determined it was twice the surface area of the RBC.

The membrane is fluid and dynamic, not rigid or crystalline.

In hypertonic environments, the external water potential is lower than the cell, causing water to exit by osmosis.

Channel proteins provide a physical pathway, whereas carrier proteins undergo conformational changes to transport substances.