lipids

Question 1

1. Describe the structure of a triglyceride

Answer 1

A triglyceride is a glycerol molecule joined to 3 fatty acids using a condensation reaction, making 3 ester bonds.

Question 2

2. Describe the structure of a phospholipid

Answer 2

A phospholipid is a glycerol molecule joined to 2 fatty acids and an inorganic phosphate group using condensation reactions, make 3 ester bonds. The molecule has a non-polar tail that is hydrophobic and a polar head that is hydrophilic.

Question 3

3. Describe an unsaturated fatty acid.

Answer 3

A hydrocarbon chain that has one or more double bonds between the carbon atoms.

Question 4

4. Give the properties of a triglyceride

Answer 4

It is a large non-polar molecule that is insoluble in water. It does not affect the water potential of the cell.

Question 5

5. Give the properties of a phospholipid

Answer 5

It is a large molecule that has a hydrophobic tail (non-polar) and a hydrophilic head (polar) due to the inorganic phosphate. It forms a bilayer in water.

Question 6

6. Explain why the hydrolysis of lipids will reduce the pH of a solution.

Answer 6

Fatty acids are released that are acidic.

Question 7

7. What is the biochemical test for a lipid?

Answer 7

Add ethanol to the test solution and shake. Then add water to the solution and shake. If there is a white emulsion a lipid is present.

Question 8

8. How are fatty acids important in the formation of new cells?

Answer 8

Fatty acids used to make phospholipids; Phospholipids in membranes; More phospholipids more membranes made; Fatty acids respired to release energy; More triglycerides more energy released; Energy used for cell production / production of named cell component;