Lipids

Question 1

Why does unsaturated fatty acid have a lower MP?

Answer 1

Unsaturated

Question 2

Features and function of Triglycerides.

Answer 2

1. Lipids have a higher proportion of carbon and hydrogen than carbohydrates. When oxidized , the same mass of lipids will release more hydrogen ions during respiration=a more effective and efficient storage of energy , esp in hibernating animals.
2. Since lipids have a higher proportion of carbon and hydrogen , when the hydrogen part is oxidized , more metabolic water is produced compared to carbohydrates=triglyceride is a better source of metabolic water.
3. Since lipids have a higher proportion of carbon and hydrogen than carbohydrates , hydrogen has a lighter molecular mass hence triglycerides are less dense. = provide buoyancy for aquatic animals.
4. Lipids are hydrophobic and thus chemically inert since they are insoluble in aqueous environments. = they aggregate together in adipose tissues away from the aqueous environments into compact forms , suitable for long term storage.

Thermal insulation: Triglycerides are good thermal insulators as they conduct heat slowly, reducing the loss of body heat.

Question 3

Features and functions of phospholipids.

Answer 3

1. Amphipathic nature allows it associate with cholesterol = regulates fluidity and stability of membrane at low and high temperatures.
2. Phosphate group forms the hydrophilic phosphate head = ablet to face aqueous environments to allow a stable interface for the barrier.
3. Hydrophobic hydrocarbon tail form a non-polar and hydrophobic core. = confers selective permeability to cell that only allows small non-polar and lipid soluble molecules to diffuse through.