Phospholipids

What is the structure of a phospholipid ?

A glycerol molecule has two fatty acids and a phosphate group bonded to it . Most of them have an even carbon number and at least one doubly bonded carbon .

What are diglycerides and where are they found ?

Found in phospholipids , and it is a phosphate group and a simple organic molecule such as choline .

What charge does a phosphate group have ?

A slight negative charge

How does the charge of a phosphate group affect the properties of phospholipids?

It is a polar molecule as the phosphate group has a slightly negative charge , so it attracts to the water , whereas the fatty acid tails are non-polar and repel water

What are the attractions to water in the two parts of the phosphid bilayer?

The heads are hydrophilic ( attracted to water ) and the tails are hydrophobic (repel water ).

What is a phosphid bilayer ?

A membrane found around cells and organelles

What are the parts of the phosphid bilayer?

What is the structure of cholesterol?

A type of lipid , but it is made of 4 carbons (not 3) .

Where is cholesterol made ?

The liver (mainly )

What is the role of cholesterol?

It regulates the fluidity of the membrane

Where is cholesterol found and why ?

In the hydrophobic part of the bilayer as it is a hydrophobic molecule.

What are 3 examples of things that are made from cholesterol?

1. Vitamin D

2. Testosterone

3. Oestrogen