MCQs

Most cytoskeletal anchors are peripheral proteins attached to the cytoplasmic surface.

Singer and Nicolson proposed the Fluid Mosaic Model in 1972.

Plants typically have higher levels of unsaturated fats to adapt to ambient temperatures.

Many peripheral proteins are connected to the cytoskeleton on the cytoplasmic side of the membrane.

It is passive (no ATP) but uses a protein facilitator.

Glycoproteins and glycolipids on the surface form the glycocalyx, involved in cell adhesion.

Selective permeability ensures only specific molecules can pass, keeping internal homeostasis.

Membrane proteins can act as enzymes to catalyze reactions at the membrane surface.

Cholesterol restricts the lateral movement of phospholipids, thus decreasing fluidity at high temperatures.

Standard plasma membranes are approximately 7.5 nanometers (or 75 Angstroms) in width.

Maintaining concentration gradients against the electrochemical gradient necessitates active transport.

The "kinks" created by double bonds prevent tight packing, which lowers the melting point and increases fluidity.

Hormones and other signaling molecules bind to glycoprotein receptors on the cell surface.

Peripheral proteins are bound to the surface, not embedded, making them easier to isolate.

The phosphate group is ionized and hydrophilic, ensuring the "head" interacts with the aqueous environment.

Simple diffusion occurs directly through the lipid bilayer for small, non-polar molecules.

Lipids can self-seal due to the hydrophobic effect, reforming the bilayer automatically.

Cholesterol intercalates between the fatty acid tails, stabilizing the membrane.

Plasmalemma is a biological synonym for the plasma membrane.