Food Science - Definitions.11111111111111ppt

Food Science - Definitions.

1. Food ScienceFood Science
Nutrition - DefinitionsNutrition - Definitions
© PDST Home Economics

2. DefinitionsDefinitions
Nutrition: study of foods and their effects on the body.Nutrition: study of foods and their effects on the body.
Nutrients: Chemical components of food needed for Nutrients: Chemical components of food needed for
growth & repair of cells, providing heat and energy and growth & repair of cells, providing heat and energy and
proper body functioning.proper body functioning.
Macronutrients: nutrients needed in large amountsMacronutrients: nutrients needed in large amounts
(grams g) by the body e.g. protein, fat, carbohydrate.(grams g) by the body e.g. protein, fat, carbohydrate.
Micronutrients: nutrients needed by the body in very Micronutrients: nutrients needed by the body in very
small amounts (milligrams mg, micrograms small amounts (milligrams mg, micrograms μμg) by the body g) by the body
e.g. vitamins and minerals.e.g. vitamins and minerals.

3. DefinitionsDefinitions
ElementsElements: simple substances that cannot be broken into : simple substances that cannot be broken into
anything simpler. Nutrients are made of molecules made up anything simpler. Nutrients are made of molecules made up
of these elements.of these elements.
Organic NutrientsOrganic Nutrients: Nutrients that contain the element : Nutrients that contain the element
CarbonCarbon e.g. protein, lipid, carbohydrate and vitamins. e.g. protein, lipid, carbohydrate and vitamins.
Inorganic NutrientsInorganic Nutrients: do not contain the element Carbon : do not contain the element Carbon
e.g. minerals elements like Iron and Calcium.e.g. minerals elements like Iron and Calcium.
Metabolism: Metabolism: the total of chemical reactionsthe total of chemical reactions which occur in which occur in
the body. There are two types of metabolic reactions:the body. There are two types of metabolic reactions:
(a) (a) Catabolic reactionsCatabolic reactions where big molecules are broken where big molecules are broken
down and energy is released (e.g. cellular respiration). down and energy is released (e.g. cellular respiration).
(b) (b) Anabolic reactionsAnabolic reactions where small molecules are built into where small molecules are built into
bigger ones using up energy (e.g. Growth).bigger ones using up energy (e.g. Growth).

4. DefinitionsDefinitions
Enzymes: Biological catalysts that control chemical Enzymes: Biological catalysts that control chemical
reactions in living things e.g. salivary amylase.reactions in living things e.g. salivary amylase.
Substrate: Substance the enzyme works on e.g. Substrate: Substance the enzyme works on e.g.
starch is the substrate for salivary amylase.starch is the substrate for salivary amylase.
Product: end result of the reaction controlled by the Product: end result of the reaction controlled by the
enzyme e.g. maltose is the product of the action of enzyme e.g. maltose is the product of the action of
salivary amylase on starch.salivary amylase on starch.

5. DefinitionsDefinitions
Malnutrition: an imbalance in the diet, it could be due Malnutrition: an imbalance in the diet, it could be due
to too much of a nutrient e.g. obesity, or too little of to too much of a nutrient e.g. obesity, or too little of
a nutrient e.g. anaemia.a nutrient e.g. anaemia.
Undernutrition: result of starvation e.g. Kwashiorkor Undernutrition: result of starvation e.g. Kwashiorkor
and Marasmus due to lack of protein in the dietand Marasmus due to lack of protein in the diet