fluid mosaic model and its components

Question 1

describe the fluid mosaic model of membranes

Answer 1

fluid: phospholipid bilayer in which individual phospholipids can move = membrane was flexible shape
mosaic: extrinsic and intrinsic proteins of different sizes and shapes are embedded

Question 2

explain the role of cholesterol in membranes

Answer 2

steroid molecule in some plasma membranes; connects phospholipids and reduces fluidity to make bilayer more stable

Question 3

explain the role of glycolipids in membranes

Answer 3

cell signalling and cell recognition

Question 4

explain the functions of extrinsic transmembrane proteins in membranes

Answer 4

• binding sites / receptors e.g. for hormones and drugs
• antigens (glycoproteins)
• bind cells together
• involved in cell signalling

Question 5

explain the role functions of intrinsic transmembrane proteins in membranes

Answer 5

• electron carriers (respiration / photosynthesis)
• channel proteins (faciliated diffusion)
• carrier proteins (faciliated diffusion / active transport)