2.1.2: Lipids

Question 1

What are the main components of phospholipids?

Answer 1

Phospholipids are made up of a glycerol molecule, two fatty acid chains, and a phosphate group.

The phosphate group is attached to the glycerol.

Question 2

What type of reactions bond fatty acids to glycerol in phospholipids?

Answer 2

Two condensation reactions result in two ester bonds.

This process involves the removal of water to form the bonds.

Question 3

What is the hydrophilic part of a phospholipid called?

Answer 3

Hydrophilic ‘head’.

This head can interact with water due to its charged nature.

Question 4

What is the hydrophobic part of a phospholipid called?

Answer 4

Hydrophobic ‘tail’.

This tail repels water but mixes with fats.

Question 5

Why are phospholipids classified as polar molecules?

Answer 5

Due to the presence of a hydrophilic head and a hydrophobic tail that act differently.

This duality allows phospholipids to interact with both water and fats.

Question 6

What happens to phospholipids when placed in water?

Answer 6

They move to a position where the heads are exposed to water, and the tails are not.

This arrangement is crucial for the formation of cellular membranes.

Question 7

Fill in the blank: The phosphate group in phospholipids is described as the _______.

Answer 7

hydrophilic ‘head’.

Question 8

Fill in the blank: The fatty acid chain in phospholipids is known as the _______.

Answer 8

hydrophobic ‘tail’.

Question 9

What are the two types of fatty acids mentioned in relation to phospholipids?

Answer 9

Saturated fatty acid and unsaturated fatty acid.

These types affect the fluidity and properties of the phospholipid bilayer.

Question 10

What structure do phospholipids form in an aqueous environment?

Answer 10

Phospholipid bilayer.

This bilayer is fundamental for cell membrane formation.