Phospholipids

Properties of phospholipids

-phosphate grouo is negativly charged ans attracts water (hydrophillic) -fatty acid molecules are hydrophobic and repel water -a phospholipid is therefore made up of 2 parts: a hydrophobic tail and a hydrophillic head.

Simplified structure of phospholipid

-polar head that attracts water (hydrophillic) -fatty acid tail that repels water (hydrophobic)

What are phospholipids?

-special type of lipid -one of the fatty acid groups is replaced by a phosphate group

How is the structure of a phospholipid adapted to its function?

1. It's a polar molecule with a hydrophillic phosphate head and a hydrophobic tail consisting of 2 fatty acids. This means that in an aqueous environment the molecules form a bilayer within cell-surface membranes. This forms a hydrophobic barrier between the inside and the outside of the cell. 2. Their structure allows them to combine with carbohydrates within the cell surface membrane to form glycolipids. These are important in cell recognition.

Phospholipids in water

Hydrophillic heads attracted to H2O Hydrophobic tails hide from H2O -can self assemble into bubbles (bubble=micelle) (can also form a bilayer)

Structure of phospholipids

Triglyceride + phosphoric acid = phospholipid