5.1 Structure of Membranes

Question 1

What’s the structure of plasma membranes

Answer 1

Made of a phosphide bilayer
Hydrophilic phosphate heads form very outer layer
Hydrophobic phosphate heads for inner layer
Contain lipids and proteins which are particular to each cell

Question 2

what are 2 types of proteins in plasma membranes

Answer 2

Intrinsic and extrinsic

Question 3

What are Intrinsic (integral) proteins

Answer 3

Embedded through both layers of the bilayer
Have amino acids with a hydrophobic R-group on their external surface which interact with the hydrophobic core of the membrane, keeping it in place.
Channel proteins: provide a hydrophobic channel for passive movement of polar molecules and ions.
Carrier proteins: part of allowing passive movement and active transport into cells; often involves shape of the protein changing.

Question 4

What are glycoproteins and glycolipids (intrinsic proteins)

Answer 4

Glycoproteins: embedded in cell-surface with attached carbohydrate (sugar) chains; play a role of cell adhesion and and as receptors for cell signalling.

Glycolipids: similar to glycoproteins; lipids with attached carbohydrate (sugar) chains; can be called cell-markers or antigens which help in the immune system.

Question 5

What’s Cell signalling

Answer 5

When the chemical binds to the receptor, it elicits a response from the cell. This may cause a direct response or a series of events.
Examples include:
Receptors for neurotransmitter