F2 Science Chapter 2 Nutrition

Chapter 2 Nutrition a) Carbohydrates -To supply energy b) Protein -To replace body tissues -To build new cells -Required for the formation of enzymes, hormones, haemoglobies and antibodies c) Fats -Help to keep our body warm -Protects organ like heart and kidney from damage -Dissolves vitamins A, D, E, and K d) Vitamins -To maintain a healthy body and to prevent diseases (i)Vitamin Ato prevent night-blindness and skin infections (ii)Vitamin Bto prevent beri-beri and pallegra and anaemia (iii)Vitamin Cto prevent scurvy (bleeding gums) (iv)Vitamin Dto prevent rickets and tooth decay (v)Vitamin Eto prevent sterility (vi)Vitamin Kblood clotting e) Minerals Mineral Source Function Deficiency disease Calcium Cheese, milk, eggs, -Strong bones and -Rickets green vegetables teeth -Osteoporosis -blood clotting -Prolonged bleeding -Muscle and nerve -Muscular cramps activities Sodium Table salt, cheese, -Maintains body -Muscular cramps meat fluid -Proper functioning of nerves Iron Meat, eggs, green -needed to form -Anaemia vegetables raemoglobin in red blood cell Iodine Seafood, iodised salt -Needed to make -Goitre (swelling of hormones of the the thyroid gland in thyroid gland the neck Phosphorus Eggs, meat, milk, -Strong bones and )-Rickets cheese, vegetables teeth -Weakness -Muscle contraction -Stores energy Potassium Meat, nuts, bananas -Maintains body -Weak muscle fluid -Paralysis -Proper functioning of nerves -Regulations of heartbeat

f) Water -To dissolve chemicals in the body - To regulate our body temperature -To dispose waste substances like urea and salt through urine and sweat g) Fibre -To prevent constipation Food Test Food Tests Starch Put a few drops of iodine on starchy food Glucose Protein Fats

A few drops of Benedict’s solution or Ehling’s solution and the food substances are heated in a water bath A few of Million’s reagent and the food substances are heated in a water bath Rub the food substances on a filter paper

Human Digestive System Organs Mouth

Oesophagu s -

Secretion

Saliva

Enzymes

Salivary amylase

-

Actions

Starch Maltose

Peristalsis

Stomach i)Gastric juice ii)hydrochlo ric acid Protease

Results A blue black color is formed if the substances contains starch A brick red precipitate is form if the food substances contains glucose A red precipitate is formed if the food substances contains protein A translucent grease mark is formed if the food contains fat. Duodenum

i)Bile ii) Pancreatic juice i)amylase ii)Protease iii)Lipase Emulsifies Protein Polypeptides fat into oil droplets -Kills the bacteria in Starch the food maltose -Provides an Protein acidic Polypeptides medium Fats suitable for Fatty acid + the action of glycerol protease

Small Intestine -

i)maltose ii)Protease iii)Lipase Maltose Glucose Polypeptides  amino acids Fats Fatty Acid + glycerol