Nurtition

Carbohydrates

- Contain C H O

- The principle energy source, 50 -

85%

Types of carbohydrate

Starch

- A polysaccharide, two chains of

glucose molecules

- Glycogen is "animal starch"

Cellulose

- Fibre

- A polysaccharide

- Not broken down by digestive enzymes

in people

- Broken down by some bacteria and

protozoa

Sugar

Monosaccharides;

glucose, fructose, galactose.

C H O

Each is one unit of sugar

Disaccharides;

sucrose, lactose, maltose

C₆H₁₂O₆ + C₆H₁₂O₆ ------> C₁₂H₂₂O₁₁ + H₂O

Two unit sugars

Fats, (lipids).

- Provide energy, 40% in UK

- Supply fat soluble vitamins

- Supply essential fatty acids which

are polyunsaturated

- Such high density lipids may lower

serum LDLs

- Composed of three fatty acids and a

glycerol group

Protein

- Growth and repair

- C H O N and others eg. S

- 3.5% of body protein may be broken

down and resynthesized daily

- 93 g/day in UK

- 0.8 g/day needed

Baby - five times more

Toddlers - two and a half

Adolescents - one and a half

- 21 amino acids, 8 essential

- Made up by bread and cheese, rice

and dhal

- Transamination

- Deamination

Electrolytes and minerals

- Sodium

- Potassium

Calcium

- Teeth and bones

- 700 mg turnover per day in an adult

- Children need 160 mg/day

Phosphorus

- Found in bones

Magnesium

- Used in enzymes

Iron

- Haemoglobin and myoglobin

Trace elements

Iodine, Thyroxine

Fluoride, Teeth

Copper, Haematogenesis

Cobalt, Part of vit B12

Zinc, Used in enzymes, Wound healing, Maturation in children

Magnesium, Used in enzymes

Selenium, Antioxident

Vitamins

Organic compounds needed for normal physiology which the body is unable to synthesize.

Fat soluble and water soluble

Vit A (retinol)

- Used by rods

- May be synthesized from beta

carotene

Vit D (cholecalciferol)

- Can be synthesized from UV light

- Promotes Ca uptake

- Promotes Ca deposition in bones

Vit E

- Antioxident

- Maintenance of muscle, prevention of

abortion and sterility in rats

Vit K

- Needed for prothrombin formation

- Synthesized by E. coli

Vit C (ascorbic acid)

- Antioxident

- Wound healing

Vit B group (thiamine, nicotinic acid, riboflavine)

- Part of enzymic systems

Vit B12 (cynocabalamine)

- Combines with intrinsic factor in

haemopoesis

Folic acid

- Haemopoesis

- Enzymic activity

- Needed for cell division

Dietary deficiencies

Protein kwashiorkor

Carbohydrates marasmus

Fat fat soluble vitamin deficiency

Water dehydration

Fibre diarrhoea, constipation, diverticulitis, colonic cancer

Minerals

Iron anaemia

Iodine cretinism, goitre

Sodium stokers cramp

Potassium electrolyte imbalance

Calcium rickets, tetany, dental caries, bone loss

Vitamins

A night blindness

B beri beri

B12 pernicious anaemia

C scurvy

D rickets

E ?sterility, poor cell division

K slow blood clotting