3. Fatty acid- is a nutrient which contains the key elements of carbon, hydrogen and oxygen. It looks like a carbohydrate but has different proportions. Fatty acids contain amino acids and glycerol.

Fatty acids are grouped into two categories according to their melting point.

Saturated fatty acid has a high melting point and has many carbon and hydrogen atoms in its molecule. There are lauric acid, myristic acid, palmitic acid and stearic acid. Most saturated fatty acids come from animal and coconut fat. Saturated fatty acid increase the cholesterol

level in our blood. It is found mostly in egg yolks and organ meats such as liver, brain and kidney. If a person consumes saturated fatty acid, it may cause obstructions in the blood vessels, vascular coagulation, hypertension etc. To decrease the cholesterol level in the blood, you should consume low fat food and avoid consuming egg yolk and animal meat especially their fatty organs.

Unsaturated fatty acid has a low melting point. The molecules have lower numbers of

carbon and hydrogen atoms. Most unsaturated fatty acids come from the fat of cold-blooded animal,

fish liver oil and plants. Unsaturated fatty acids have a distinct odor because it can easily bond with

oxygen atoms in the air. Unsaturated fatty acids will react with hydrogen which is the main method of making margarine.

The amino acids which the body needs are the ones that the body cannot synthesize itself, so the body must receive them from external nutrients. Most fats coming from plants are unsaturated fatty acids e.g.

Oleic acid (C18H34O2) is found in olive and peanut oil

Linoleic Acid (C18H32O2) is found in sunflower, corn and safflower oil.

The advantages of unsaturated fatty acids to the body are

(1) a healthy body

(2) body growth in children

(3) healthy skin

(4) decreased blood cholesterol levels.

If the body lacks fatty acids, it will stop growing and the skin might become inflamed. Fatty acids are a high energy nutrient. A gram of fat will give 9 kilocalories energy. Fatty acids also help to absorb vitamin A, D, E, and K. If the body lacks fatty acids, it will also lack the vitamins A, D, E and K.

Triglyceride is an ester derived from three fatty acids and glycerol.

Things to remember

(1) The melting point of saturated fatty acids depends on the amount of carbon and hydrogen atoms in 1 molecule.

(2) The melting point for unsaturated fatty acids will be higher when the amount of carbon atom stays equal but the number of hydrogen atoms increases.

4. Vitamins - are necessary for our body because they will help the body to work normally. Vitamins have to come from food because our body cannot produce or synthesize them.

(1) Vitamin that is soluble in oil or fat is vitamin C. This vitamin will break down easily when in light or heat. So it is not accumulated in the body. If the body gets overdose vitamin C, it will cause an allergy.

(2) Vitamins that are soluble in water are vitamin B and vitamin C. These vitamins will break down easily when in light or heat. So they are not accumulated in the body. If the body gets overdoes,they will be excreted through urine or sweat.

1. Vitamin A is found in meat, milk, egg yolk, butter, fish liver oil, vegetable and fruit, especially in yellow fruits such as papaya, pumpkin etc. The benefits of vitamin A are as follow.

· Helps to maintain healthy eyes.

· Helps to build teeth enamel.

· Help to refresh the skin and not form scales.

Disadvantage of vitamin A in overdose can cause feeling queasy, hair fall and skin itching.

2. Vitamin D is found in fish liver oil, egg yolk, butter. Our body can synthesize it by using sunlight. The advantages of vitamin D are as follows.

· Control the amount of calcium in the blood.

· Help to prevent rickets.

· Help to build strong bones and teeth.

Disadvantage of vitamin D in overdose may cause feeling queasy, decreasing weight, frequent urination, constipation and high calcium levels in the blood.

3. Vitamin E is found in the oil of vegetables, e.g. grain, dark green vegetable, bean and milk. It has the following advantages.

- Prevent becoming sterile and miscarriage.

- Prevent the muscle from silting and muscle weakness.

- Prevent the blood from being destroyed.

4. Vitamin K is caused by the synthesis of intestinal bacteria from green and yellow foods such as cauliflower, soybeans, cabbage and tomato. The advantage is to help production of prothrombin by the liver and to help in blood coagulation. If the body lacks vitamin K, the blood will clot slowly. A newborn does not have intestinal bacteria to produce vitamin K. If they are wounded, they may bleed to death.

5. Vitamin B1 (Thiamine) is mostly found in coarse rice, meat, beans, rice straw mushrooms, sesame seeds, rice bran, yeast and the green leaves of vegetables. If you lack vitamin B1, you may get beriberi, become bored with food and moody.

6. Vitamin B2 (Riboflavin) is mostly found in liver, kidney, heart, fish's roe, white egg, bean and shoots of vegetables. If you lack vitamin B2, it may cause canker sore, skin rash and headache.

Advantages of vitamin B2

- Help to build red blood cells.

- Help to metabolize protein and carbohydrate.

- Help to nourish the skin.

7. Vitamin B12 (Cobalamin) is mostly found in milk, cheese, egg, shell, pickled fish and shrimp paste. The advantage is to prevent the nervous system and anemia.

8. Vitamin C (Ascorbic acid) is found in fresh vegetable, sour fruit and growing plants such as bean sprouts, top of gourd. The advantages are as follow.

- Prevent scurvy

- Help to strengthen the wall of blood vessels.

- Help to absorb other nutrients.

- Help to refresh the body.