Classes of Food

 

3.1

 Classes of Food

 
Classes of Food

 

  1. Carbohydrate
  2. Protein
  3. Fat
  4. Vitamin
  5. Mineral
  6. Fibre
  7. Water
   

1) Carbohydrate

  • Carbohydrate contains carbon, hydrogen and oxygen
  • It supplies a lot of energy
  • Examples: Starch - food stored in plants, Glycogen - food stored in animals, Cellulose - forms the cell wall of plants
   

2) Protein

  • Protein contains carbon, hydrogen, oxygen and nitrogen
  • Required for growth, repair damaged tissues and to replace dead cells
  • Used to synthesise enzymes, hormones and antibodies
  • Example : Chicken, Meat and Seafood
   

3) Fat         

  • Fat contains carbon, hydrogen and oxygen
  • Formed from glycerol and fatty acid
  • Fat is a high energy source and storage
  • Protects the organs, act as transporter for vitamin A,D,E and K and a heat insulator to regulate body temperature

 

   

4) Vitamin     

  • Vitamin is needed in small quantities to maintain good health
   
Vitamins
\(\swarrow\) \(\searrow\)

Water-soluble vitamins

(Vitamin B and C)

Fat-soluble vitamins

(Vitamin A,D,E and K)

   

 

Type, source, importance and effects of vitamin deficiency

Vitamin Function Effects of deficiency

A

Milk

Egg yolk

Maintains skin health Skin diseases

B

Yeast

Liver

Formation of blood cells

Beri-beri

Anaemia

C

Fruits

Vegetables

Maintains the health of gums and mouth Scurvy (bleeding gums)

D

Butter

Eggs

Strengthens tooth enamel

Rickets

Toothache

E

Grains

Green vegetables

Maintains the functions of the reproductive system

Sterility

Foetus miscarriage

K

Milk 

Egg yolk

Speeds up the blood-clotting process Prolonged bleeding
   

5) Fibre

  • Fibre comprises of cellulose that is found in the cell wall of plants
  • Very important to stimulate peristalsis which prevents constipation
  • Example : Vegetables, Grains and High fibre bread
   

6) Mineral

  • Minerals do not supply energy,but are required in small quantities to regulate body process to maintain health
   

7) Water

  • Water contains hydrogen and oxygen
  • Acts as a chemical solvent, transportation medium and regulates body temperature

 

Types,sources,importance and effects of mineral deficiency

Mineral Importance and effects of defienciecy

Calcium

Milk,Anchovies

Strengthens bones and teeth

Effect: 

Rickets             

Osteoporosis

Sodium

Salt,Meat

Maintains the functions of the nervous system

Effect: Muscle cramps

Iron

Liver,Meat

Build haemoglobin in the blood

Effect: Anaemia

Iodine

Seafood,Fruits

Helps with the functions of thyroid gland

Effect: Goiter

Phosphorus

Cheese,Meat

Forms nucleic acid in DNA and RNA

Effect: 

Brittle teeth       

Cannot build DNA and RNA

Potassium

Plants and animals

Helps with muscle contraction

Effect: Paralysis