Biochemistry Lipids

Question 1

Describe saturated fatty acids

Answer 1

Saturated with hydrogen bonds, therefore are more stable and fit together neatly. Saturated fatty acids are solids are room temperature like butter.

Question 2

Describe unsaturated fatty acids

Answer 2

Unsaturated fatty acids have at least one double bond configuration which allows the formation of kinks. The kinks make these fatty acids less likely to stack and therefore are liquids at room temperature.

Question 3

What are phosphoglycerides?

Answer 3

phosphoglycerides are triglycerides, but one of the fatty acids chains has been replaced with a polar phosphate group.

Question 4

What are Spingolipids?

Answer 4

Similar to phosphoglycerides, but with a spingosine backbone instead of a glycerol backbone.

Question 5

What are waxes?

Answer 5

esters of long-chain fatty acids with long-chain alcohols. Used to prevent dehydration in animals.

Question 6

Describe steroids & cholesterol.

Answer 6

Large nonpolar molecules derived from terpenes.

Cholesterol is derived from steroids and are important for membrane fluidity.

Question 7

Fat soluble vitamins

Answer 7

Stored in the fat. AEDK.

Question 8

Function of Vitamin A

Answer 8

Carotene, unsaturated hydrocarbon that is important in vision, growth and development, and immune function.

Question 9

Function of Vitamin D

Answer 9

converted into calcitriol which helps with calcium uptake.

Question 10

Function of Vitamin E

Answer 10

Aromatic ring which destroys free radicals and acts as an antioxidant.

Question 11

Function of Vitamin K

Answer 11

Helps with coagulation.

Question 12

Relate lipids and energy storage.

Answer 12

Fatty acids and triglycerides are fantastic ways to store energy. More energy comes from the oxidation of these than sugars.

Question 13

Describe saponification

Answer 13

Ester hydrolysis of triglycerides using a strong base. Removes the fatty acids from the glycerol backbone.

Question 14

What are the two ways to name fatty acids.

Answer 14

Start at carbonyl end @ carbon one, use delta sign to represent where the double bonds are, and whether it is trans or cid.

Start at the omega end @ carbon one and count where the double bonds are, and whether it is trans or cis.

Question 15

How do unsaturated compounds effect the melting point?

Answer 15

Kinks decrease the amount of energy required to break the bond, therefore the melting point is decreased.

Question 16

How many NaOH molecules are required for saponification of triglycerides?

Answer 16

3, one per fatty acid chain.