Fluid mosaic model

Question 1

What does it means by fluid?

Answer 1

Components can move freely along the membrane

Question 2

What are the functions of the plasma membrane?

Answer 2

• Compartmentalisation
  Provides specific conditions for certain reactions to occur
• Site of chemical reaction
  Holds proteins/enzymes that are involved in certain chemical reactions
• Acts as a barrier
  Partially permeable membrane, only allows small, lipid-soluble/non polar substances to diffuse across (phospholipid bilayer)

Question 3

What is a carrier protein?

Answer 3

It is a protein on the inside that is able to change its shape using energy to face outwards.
Used to transport moleules across membrane
* Involved in active transport mainly sometimes passive (facilitated diffusion)
Because it uses energy to change shape

Question 4

What is a channel protein?

Answer 4

Allows faciltated diffusion
Because polar molecules cannot pass through the phospholipid bilayer

Question 5

What are the similarities of channel and carrier protein?

Answer 5

They are both selective so they have specific channels for specific molecules

E.g aquaporins are channel proteins that only allow water to go through

Question 6

What is a glycolipid and glycoprotein?

Answer 6

Glycolipid - carbohydrate chain attached to a phospholipid
Glycoprotein - carbohydrate chain attached to a protein
They can be receptors or antigens

Question 7

What is the role of cholesterol?

Answer 7

regulates fluidity

Question 8

What makes up the fluid mosaic model?

Answer 8

Carrier and channel proteins
glycolipids and glycoprotiens
cholesterol

Question 9

What is inbetween different phospholipids?

Answer 9

Weak intermolecular forces that stabilise the structure