BIOLOGY: Food and Nutrition

FOOD AND NUTRITION

Nutrition – process of taking in and using food

Nutrients – microfood particles
- substances needed by the body for growth, repair and maintenance

3 processes to obtain nutrients

1.    Mechanical Digestion
- the food that we eat is broken down into smaller ones
- physical change

2.    Chemical Digestion
- the food that we eat will be changed into simple molecules
- ex. Potato – carbohydrates – glucose – nutrients

3.    Absorption
- the nutrients will be taken into individual cells

5 Chemical components of food

CARBOHYDRATES
- carbon, hydrogen, oxygen (1:2:1)
- not essential because protein also has carbon, hydrogen & oxygen

- Fiber aids in indigestion; serves as roughage; decreases cholesterol concentration in the blood; stimulates the feeling of satisfaction (satiety)

Food Pyramid daily intakes

1.    Fats and Oils (1 – 2)

2.    Meat, Fish, Eggs, Nuts (2 – 3)

3.    Dairy Products (2 – 3)

4.    Vegetable Group (3 – 5)

5.    Fruit Group (2 – 4)

6.    Carbohydrates (6 – 11)

Classification:

1.    Simple sugar / monosaccharide
a. glucose
b. galactose
c. fructose

2.    Double Sugar / disaccharide
a. maltose – glucose + glucose
b. lactose – glucose + galactose
c. sucrose – glucose + fructose

3.    Complex Carbohydrates / Polysaccharide
a. starch
    - stored food in plants
    - are located at the roots(root crops)
b. glycogen
    - stored food in animals
    - stored food in the liver
    - can be used as a source of energy when deprived of meat
c. cellulose
    - 300 amino acids
          - 20 can synthesize proteins
                - 9 essential amino acids
                - 11 non - essential amino acids (10 if children)

Essential	Non-essential
Histidine	Alanine
Isoleucine	Arginine
Leucine	Asparagine
Lysine	Asparctic acid
Methionine	Cysteine
Phenylalanine	Glutamic acid
Threonine	Glutamine
Tryptophan	Glycine
Valine	Proline
	Serine
	Tyrosine

     

LIPIDS
- used as energy and to make biological molecules
- carbon, hydrogen, oxygen
- can be made from smooth ER
- lipids ingested can be used as:
     a. fuel
     b. components of cell membrane
     c. compounds such as:
          - steroid hormones
          - bile salt

Essential fatty acids
1. Linoleic
2. Linolenic
3. Arachidonic acid

Non essential fatty acids
1. Fats
2. Cholesteral
3. Phospholipids
4. Prostaglandins

Saturated fat
- melting point is higher
- solid form in room temp.

Non-saturated fat
- melting point is lower
- liquid form in room temp.

Polyunsaturated fat
- corn, soy, safflower, cottonseed

Monounsaturated fat
- olive, canola, peanut

High saturated fat
- coconut, palm

Mainly saturated fat
- butter

PROTEINS 56g
- abundant in cells
- for cellular transport
- carbon, hydrogen, oxygen, nitrogen, (sulfur & phosphorus)
- essential building blocks of cells
     a. serves as enzymes
     b. used to make needed enzymes