- Soluble
- Too large (needs to be digested)
Sucrose glucose + fructose
Lactose glucose + galactose
Maltose glucose + glucose
Polysaccharides – many sugar units:
- Starch- plant storage substance, digested by amylase enzymes in salvia and pancreatic juice
- Cellulose- found in plan cell walls, cannot be digested by mammals as do not have cellulase, helps stimulate muscles in gut (peristalsis)
- Glycogen- animal storage
Too much carb causes obesity
Too much sugar can rot teeth
Fats
- Contain: carbon, hydrogen, oxygen
- Found in: butter, oil, margarine, peanuts, fatty meat
- Needed for a) energy
b) Insulation
c) Storage of vit A and D
- Excess stored under skin and around body organs
- Made from fatty acids and glycerol
Too much cholesterol blocks arteries
Too much fat causes obesity
Proteins
- Contain: carbon, hydrogen, oxygen, nitrogen
- Found: meat, eggs, fish, cheese, pulses
- Needed for growth and repair
- Not stored- deaminated in liver nitrogen urea urine
- Made from single cells called amino acids
- Deficiency causes disease - Kwashiorkor
Mineral salts
E.g. iron, calcium…needed in small quantities
-
Iron found in meat, liver, kidney, spinach, brocolli
Needed to make haemoglobin
Lack causes anaemia and tiredness
-
Calcium found in milk, dairy products
Needed to strengthen teeth, bones
Lack causes rickets
Vitamins
e.g. vitamin C, D…needed in small amounts
-
Vitamin C water soluble & not stored in body
Found in citrus fruits, blackcurrants, tomatoes
Needed to heal wounds
Lack causes scurvy, reduced resistance to disease
