Biological membrane structure

Question 1

Describe the key structural components of the biological membrane.

Answer 1

Phospholipids form lipid bilayer, cholesterol modulates fluidity of the membrane, carbohydrates (glycoproteins, glycolipids, and proteoglycans) form a layer around the outside of the membrane referred to as the glycocalyx

Question 2

Explain the principal functions of the ‘lipid bilayer’ of the biological membrane.

Answer 2

Physical isolation, holds molecules inside, regulates exchange via transport, sensitive and provides unique intracellular pH, provides structural support.

Question 3

Describe the interaction between proteins and lipids of the biological membrane.

Answer 3

Proteins anchor cell membranes to each other or external structures, recognition proteins identify the cell and prevent attack by immune system, receptors bind specific ligands in ECM, carrier proteins, leak channels, and gated channels contribute to transport/exchange

Question 4

Describe the different modes of transport across the biological membrane.

Answer 4

Passive diffusion, facilitated diffusion, active transport (x3), endocytosis, exocytosis.