Glycerophospholipids

Question 1

What are the 3 main types of membrane lipids?

Answer 1

1. Glycerophospholipids
2. Sphingolipids
3. Sterols (cholesterol)

Question 2

What is the most abundant phospholipid found in cells?

Answer 2

Glycerophospholipids

Question 3

Structure of glycerophospholipids?

Answer 3

Amphipathic structure:

• Hydrophilic (polar) head
• Hydrophobic (non-polar) tail

Question 4

What makes up polar head?

Answer 4

Glycerol and phosphate

Question 5

What makes up non-polar tail?

Answer 5

Hydrocarbon chains

Question 6

What does segregation of polarity and non-polarity cause?

Answer 6

Spontaneous aggregation - minimises energetically unfavourable contacts by keeping similar regions of molecules apart

Question 7

What 3 components are glycerophospholipids made up of?

Answer 7

1. A phosphorylated head group
2. A 3-carbon glycerol backbone
3. 2 hydrocarbon fatty acid chains

Question 8

What is the phosphorylated head attached to?

Answer 8

Ester-linked to carbon 3 of glycerol backbone

Question 9

What are the 2 fatty acid chains attached to?

Answer 9

The other 2 carbon atoms through ester oxygen (esterified t§o OH groups of glycerol)

Question 10

Describe saturation of fatty acid attached to carbon 1 (sn-1 fatty acid)

Answer 10

Usually saturated

Question 11

Describe saturation of fatty acid attached to carbon 2 (sn-2 fatty acid)

Answer 11

Usually unsaturated

Question 12

Which phospholipids have a net negative charge?

Answer 12

The anionic phospholipids (PS, PI, PG, CL)

Question 13

Some phospholipids are zwitterionic. What does this mean?

Answer 13

One group has positive charge and one has negative (zero charge)

Question 14

Which lipids are only found in mitochondria?

Answer 14

PG and cardiolipins