What is digestion?

a) What is digestion?

Digestion is (mechanical and chemical) the process by which large complex food molecules; are broken down into soluble molecules (for absorption across intestinal wall to bloodstream)



b) What is the importance of a balance diet in human nutrition?

A balanced diet consists of all the food types in their right proportions; it includes proteins, carbohydrates, minerals, lipids, water, vitamins and roughage; Proteins; used for growth and repair of worn out tissues; provide energy incase of acute shortage of carbohydrates/starvation; bind and transport specific molecules from one part of the body to another; structural proteins support tissues in the body e.g. bone and cartilage tissues; act as metabolic regulators such as enzymes and hormones; Carbohydrates; used to produce energy/store energy; Lipids produce energy; form of storage of energy; insulate the body; major structural components of the cell membrane; when oxidised, it provides metabolic water; Vitamins; defense against infections; form coenzymes which activate enzymes; Water; a universal solvent; medium for chemical reactions; used as coolant because of its high specific heat capacity; maintains the shape of cells; hydrolysis of many substances; transport medium in the body; Mineral salts; formation of teeth and bones; formation of hormones (e.g. thyroxine); formation of blood; maintenance of osmotic pressure of body fluid; transmission of nerve impulses; Roughage; makes food to be bulk; promotes peristalsis; and absorption of water in the large intestines; induces mucus production;