Lipids 2: phospholipids and cholesterol 2.2.7 Flashcards
1
Q
What is a phospholipid?
A
Consists of a glycerol molecule, 3 fatty acids, and a phosphate group.
2
Q
Why are phospholipids amphipathic?
A
As they have a polar region (hydrophilic - attracted) and a non polar region (hydrophobic - repelled)
3
Q
What do phospholipids form in water?
A
- Layer on the surface, with the heads facing down and tails sticking up out of the water
- Micelles, tiny balls with the tails tucked inside and the heads pointing into the water.
4
Q
What are cell membranes made out of?
A
Phospholipid bilayers
5
Q
What is cholesterol?
A
A steroid alcohol, not a triglyceride. As it is not made from fatty acids and glycerol (it is a shorter lipid molecule)
6
Q
What is the structure of cholesterol?
A
- Made from 4 carbon based rings
- Hydrophobic, pass through the hydrophobic part of the membrane
7
Q
Give 2 examples of hormones made from cholesterol
A
Oestrogen and testosterone
