Question

Biological membranes are present in all cells, and in eukaryotic cells they also form the endomembrane system. They act as gatekeepers that selectively move certain ions and compounds into and out of the cell or cell organelles.             (a) Which of the following best describes a biological membrane?

a bilayer containing lipids with hydrophilic head groups facing the extracellular fluid and cytoplasm, and hydrophobic tail groups extending inward...OR... a bilayer containing lipids with hydrophobic head groups facing the extracellular fluid and cytoplasm, and hydrophilic tail groups extending inward...OR... a bilayer containing lipids with hydrophilic head groups facing inward and hydrophobic tail groups extending toward the extracellular fluid and cytoplasm.

(b) Which of the following are components of biological membranes? select all that apply...... nucleic acids...OR...lipids...OR...protiens

Answer 1

a. Biological membrane is a bilayer containing lipids with hydrophilic head groups facing the extracellular fluid and cytoplasm and hydrophobic tail extending inward.

b. Biological membranes are composed of lipids, protiens and carbohydrates.