Organelles in the membrane

Question 1

What are all of the organelles in the plasma membrane?

Answer 1

Phospholipid, cholesterol, glycolipid, intrinsic + extrinsic proteins, and glycoproteins

Question 2

What is the role of phospholipids?

Answer 2

Attracts water with hydrophillic head outside the membrane + repels water with hydrophobic tails inside membrane. Fatty acid tails form hydrophobic core inside membrane

Question 3

What is the role of cholesterol?

Answer 3

Regulates fluidity of membranes, add stability, and prevents phospholipid tails inside membrane from bunching up too tightly

Question 4

What is the role of a glycolipid?

Answer 4

Called cell markers/antigens + are recognised by cells of the immune system

Question 5

Where are extrinsic proteins present?

Answer 5

In 1 side of the bilayer

Question 6

Where are intrinsic proteins present?

Answer 6

They’re transmembrane proteins embedded in both layers of the membrane

Question 7

What is the role of glycoproteins?

Answer 7

They’re intrinsic proteins with carbohydrates (sugar) attached. Functions are cell adhesion + cell signalling

Question 8

What are the 2 types of proteins?

Answer 8

Channel, carrier

Question 9

What is a channel protein?

Answer 9

Passive transport, H to L

Question 10

What is a carrier protein?

Answer 10

Passive active transport, need energy from ATP

Question 11

What is the model of the plasma membrane?

Answer 11

Fluid-mosaic model, by Singer + Nicolson. Approx 7-10nm wide