F3 - SEM1 - LIPIDS

Question 1

What elements is Lipids composed of?

Answer 1

Carbon
Hydrogen
Oxygen
Phosphorus

Question 2

Is Lipids soluble in water?

Answer 2

No but is soluble in organic solvent

Question 3

What is most common lipids?

Answer 3

Triglyceride

Question 4

What are the properties of Lipids?

Answer 4

Composed of C, H, O, P; H:O ratio is higher
Not soluble in water but in organic solvents

Question 5

Name 2 types of Lipids

Answer 5

Solid: Fat
Liquid: Oil
Other: Cholesterol, Wax, Phospholipid

Question 6

How to form Triglycerides?

Answer 6

Glycerol + Fatty acids (can be same or different fatty acids) - 3 H2O (condensation) = triglyceride molecules

Diagram

Question 7

What happens when Triglyceride molecules go through hydrolysis (+ 3H2O)?

Answer 7

Glycerol + Fatty acids

Question 8

What are the 2 types of Fatty acids?

Answer 8

Saturated (e.g. stearate)
Unsaturated
- mono (e.g. oleate)
- poly (e.g. linoleate)

Question 9

What are the functions of Lipids?

Answer 9

Source of energy - energy reserve, 38.9Kj/g
Structure material
Formation of some regulating substances - e.g. sex hormones
Insulator for heat - under the skin to prevent heat loss
Shock absorber - around/protect internal organs
Water proof - e.g skin surface
Absorption, Transport and Storage of fat-soluble nutrients - e.g. Vitamin D, Vitamin A

Question 10

What are the sources of Lipids?

Answer 10

From animal
- Lard
- Butter
- Fatty meat
- Milk and dairy products

From plant
- Seeds , e.g. corn, peanut, olive, but not all seeds
- Nuts
- Cashew

Question 11

How to test Lipids?

Answer 11

Drop a sample on filter paper and Wait
> translucent spot disappear = no lipid and protein
> translucent spot not disappear = lipid or protein present

Immerse filter paper into organic solvents
> permanent translucent spot = protein present
> translucent spot disappear = no protein but lipids present

Question 12

What happens when excessive uptake of Lipids?

Answer 12

Excess lipids will be stored in adipose tissue as food reserves

Question 13

How do we can the excess lipids store under skin? What are the functions?

Answer 13

Subcutaneous fat

Functions
- food reserve
- heat insulator: prevents heat loss
- shock absorbers: internal organs

Question 14

What are the advantages and disadvantages of excess lipids?

Answer 14

Advantage
- more energy preserves to tackle adverse conditions

Disadvantage
- obesity, lead to heart disease/stroke, high blood pressure, diabetes, some cancers, gallbladder disease and gallstones, gout, breathing problems