CHEMICAL REACTIONS IN THE BODY (ENZYMES, VITAMINS AND MINERALS)

PROTEINS Enzymes are a type of protein.

NATURE’S CATALYST Enzymes are proteins that act as biological catalysts. They speed up chemical reactions that take place in cells. Enzymes act by lowering the activation energies, which has a dramatic effect on how quickly reactions are completed.

ENZYME-SUBSTRATE COMPLEX The substrates bind to a site on the enzyme called the active site. The active site and the substrates have complementary shapes. The fit is so precise that the active site and substrates are often compared to a lock and key. Animation 1 min Animation 5 min

REGULATION OF ENZYME ACTIVITY Enzymes work best under ideal conditions. Temperature, pH, and regulatory molecules are all factors that can affect the activity of enzymes.

VITAMINS Organic molecules that the body needs in very small amounts are called vitamins. vitamins help perform important chemical reactions. Most vitamins must be obtained from food. However, the bacteria that live in the large intestine can synthesize vitamin K and vitamin B12.

Essential vitamins are ones that we must obtain through our diet.

14 ESSENTIAL VITAMINS

MINERALS Inorganic nutrients that the body needs, usually in small amounts, are called minerals. A constant supply of minerals in the diet is needed to replace those lost in sweat, urine, and digestive wastes.

MINERALS – SOURCES & FUNCTIONS

NUTRITION – BALANCED DIET A balanced diet provides nutrients in adequate amounts and enough energy for a person to maintain a healthful weight.

BALANCED DIET The best way to eat for health is to choose a variety of foods from each of the 5 food groups every day: vegetables and legumes (beans) Fruit grains and cereals lean meat, poultry, fish, eggs, legumes (beans) tofu, nuts, seeds milk, cheese yoghurt or alternatives.