Lipids

Question 1

What are the 2 types of lipids?

Answer 1

Phospholipids and triglycerides

Question 2

What are the properties of lipids?

Answer 2

1. Insoluble in water
2. Soluble in other solvents such as ethanol and other lipids
3. Lipids all contain C, H, O

Question 3

What are the 4 functions of triglycerides?

Answer 3

1. Buoyancy
2. Shock of absorption
3. Storage of energy
4. Thermal insulation & electrical insulation

Question 4

Explain the function of buoyancy in triglycerides

Answer 4

Many single called organisms produce oil drops to aid buoyancy

Question 5

Explain the function of shock of absorption in triglycerides

Answer 5

Organs such as kidneys have fat around them to protect against knocks and any impact

Question 6

Explain the function of storage of energy in triglycerides

Answer 6

Energy store in seeds, energy store in animals

Question 7

Explain the function of insulation in triglycerides

Answer 7

Thermal insulation by adipose tissues and electrical insulation in the neurones

Question 8

Describe the structure of a triglyceride molecule

Answer 8

One molecule of glycerol with 3 fatty acid tails bonded by an ester link through the process of condensation reaction

Question 9

Describe fatty acid tails

Answer 9

1. Can be saturated or unsaturated
2. Made of hydrocarbons (15-17 carbons)

Question 10

What is saturated hydrocarbons?

Answer 10

Hydrocarbons with no double bond only have single carbon to carbon bond which means there is more hydrogen atoms

Question 11

What is unsaturated hydrocarbons?

Answer 11

Hydrocarbon containing double carbon to carbon bond so less hydrogen atoms

Question 12

What are the properties of saturated fatty acids?

Answer 12

1. Contain single C-C bonds
2. Closely packed
3. High melting points
4. Solids at room temp
5. Animal fat
6. More hydrogens
7. Straight tail

Question 13

What are the properties of unsaturated fatty acids?

Answer 13

1. Contains one or more double C-C bonds
2. Non linear chains do not allow molecules to pack closely
3. Low melting points
4. Liquid at room temp
5. Plant oils
6. Less hydrogens
7. Kink or bend in tail

Question 14

Describe glycerol

Answer 14

1. It is a 3 carbon carbohydrate
2. Has 3 alcohol (OH) groups which link up with fatty acid groups in the fatty acids

Question 15

How many molecules of water is removed from a triglyceride in condensation reaction?

Answer 15

3

Question 16

What is the difference between triglycerides and phospholipids?

Answer 16

Triglycerides contain 3 fatty acid tails whereas phospholipids contain 2 fatty acid tails as 1 of them is replaced by a phosphate group

Question 17

What is the similarity between triglycerides and phospholipids?

Answer 17

Both are bonded with glycerol and fatty acids to make ester bonds through condensation reaction