(b) the fluid mosaiic model of membrane structure and the roles of its components

Why is it called the fluid msoaicc model.

Phospholipids give membrane flexibility

Proteins embedded vary in shape and size = mosaic

What are membranes formed from?

Phospholipid bilayer

How do intrinsic proteins play a role?

Have R group in amino acids that are hydrophobic which then interact with the hydrophobic core of the membrane (the fatty acid tails)

What is the role of membrane bound receptors

It is where drugs and hormones can bind (such as insulin for a hormone)

How are channel proteins held and what is the role?

Held by hydrophobic core of membrane and the hydrophobic R groups on external surface

It is a hydroophillic channel - alllwows the passive movement of ions and polar molecules

What kind of transport do carrier proteins do and what does carrier proteins involve?

Passive and active

Involves cell changing shape

Name the different intrinsic proteins

Channel

Carrier

Glycoproteins

Glcolipids

What is the role of glycoproetins

Cell adhesion

Receptors in cell - signalling (*e.g peptide hormones like insulin*)

What is the role of glycolipids

Celll markers / antigens

Where is the extrinsic protein

Only on ne side of the bilayer

What is the role of extrinsic proteins

Hydrophilic R group on outside surfaces

Interact with intrinsic or polar heads of phospholipids

Describe the cholesterol

Lipid with hydrophilic end and hydrophobic end

Where is cholesterol positioned

Between phospholipid and interacts with phosphate head and fatty acid tails

What is the role of cholesterol

Regulates fluidity of membrane

Adds stability (stops phsoholipids from grouping too closely)

Stops it from being too fluid in high temperatures