Lipids

Question 1

Lipids are a diverse…

Answer 1

group of chemicals.

Question 2

Most common are…

Answer 2

triglycerides = fats(solid) and oils (liquid)

Question 3

Lipids contain elements….

Answer 3

C,H and O

Question 4

Triglycerides are made of…

Answer 4

three fatty acid molecules and one glycerol molecule

Question 5

Fatty acids have…

Answer 5

-COOH group attached

Question 6

Glycerol is…

Answer 6

alcohol.

Question 7

Fatty acids joins to glycerol by…

Answer 7

condensation, forming ester bonds between two C. The final product is glyceride.

Question 8

Properties of triglycerides

Answer 8

• insoluble in water
• soluble in organic solutions e.g. ethanol or chloroform
• non-polar and hydrophobic

Question 9

Why is triglyceride soluble in organic solution?

Answer 9

Due to the long hydrocarbon tails of fatty acids.

Question 10

Roles of triglycerides

Answer 10

• energy reserve
• insulator
• buoyancy (whales)
• metabolic source of water (desert kangaroo rat)

Question 11

Why the triglycerides are good energy reserve?

Answer 11

Contain many C-H bonds, more than carbs.

Question 12

Unsaturated lipids

Answer 12

• have double bond between neighboring carbon atoms
• do not contain the maximum possible amount of H
• double bond make lipids melt more easily

Question 13

Saturated lipids

Answer 13

• no double bond

- animal lipids

Question 14

Double bond in unsaturated fatty acids causes…

Answer 14

bending.

Question 15

Phospholipids

Answer 15

• each molecule has one end which is soluble in water
• one of the fatty acids is replaced by phosphate group(hydrophilic head)
• hydrophobic tails

Question 16

Phospholipids have important…

Answer 16

function in membranes.