Biochemistry

Question 1

What is a phospholipid + its structure

Answer 1

• essential components of cell membranes
• each phospholipid molecule contains a molecule of glycerol and
  1 phosphate head which contains a phosphate ion - hydrophilic
  2 fatty acid side chains - hydrophobic

Question 2

What are the functions of phospholipids [6]

Answer 2

• Cell membrane phospholipids form a bilayer
  = hydrophilic phosphate groups are attracted to water molecules in the cytoplasm and outside the cell
  = hydrophobic tails are repelled by water molecules and hide from water in the cytoplasm and outside the cell
• can contain saturated and or unsaturated fatty acids (affects the fluidity)
  = only unsaturated fatty acids are present then there will be less fluid
  = only saturated fatty acids present then there will be more fluid

Question 3

What does a high intake of saturated fats cause?

Answer 3

Increase in heart disease
- raises the low density lipoprotein cholesterol level, which increases the incidence of atheromas in coronary artery
- this leads to blockages and eventually heart disease