Revision:Diet

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Define Diet

Diet is the total food taken in by an individual.

Define Nutrient

Nutrients are something taken in by the mouth and absorbed into the body supplying a vital need.

List the constituents of a Diet

Diet consists of Carbohydrates, Proteins, Fats, Vitamins, Minerals, Water, and Fibre.

• Carbohydrates provide instant energy
• Fats are stored energy
• Proteins - Used for the synthesis of new materials for growth, repair and rebuilding
• Vitamins - Maintain normal growth and metabolism
• Minerals - Same as vitamins but mineral rather than chemical compounds
• Water - 70% body weight - Blood, homeostasis, synthesis
• Fibre - Indigestible cellulose - Polysaccharide providing matrix for food to adhere to; aids peristalsis.

List Several Examples of Common Foods which supply some of the constituents of the diet

• Carbohydrates - Pasta
• Protein - Fish, meat, beans, nuts
• Fats - Oils, Meat, Vegetable Oils
• Vitamins
  • Retinol (Vitamin A) - Veg, Liver
  • Ascorbic Acid - Citrus Fruits
• Minerals - Dairy Products, Fish
  • Iron - Red Meats, Liver
• Fibre - Cereals, Pears
• Water - Drinks

Describe a balanced diet

A balanced diet is equilibrium between food intake and energy expenditure and a meeting of needs of bodily growth, replacement, and healthy functioning.

Biochemistry of Nutrition

List two sources of each monosaccharide, disaccharide, polysaccharide in the diet

• Monosaccharides Glucose, Ribose.
• Disaccharides Lactose (Milk), Sucrose (Fruit and Root Vegetables), Cellulose
• Polysaccharides Glycogen, Starch

Outline the fate of the products of the ingested carbohydrates including storage (as glycogen or lipid) and cell respiration

• Carbohydrate (starch) may be
  • Broken down into monosaccharide and stored as glycogen in the liver
  • Or as lipid in the under the skin
  • Used for cell respiration

List three sources of lipids in the diet=

• Meat
• Oils
• Dairy Produce

Describe the fate of the products of ingested lipids including storage, growth of membranes and cell respiration

• Used for storage
• Used for growth of membranes
• Used for Cell respiration

List Four Sources of Protein in the diet

• Fish
• Meat
• Beans
• Nuts

Outline the fate of ingested proteins including protein synthesis and deamination

• Protein Synthesis
• Deamination
  • Nitrogen removed from proteins due to excess
  • First hydrolised into constituent amino acids and then used in respiratory pathway

State that essential Amino Acids are those which must be ingested and cannot be synthesised

Describe the functions of calcium, iron, iodine, and potassium

• Iodine - Makes thyroxin ---> Controls metabolic rate. Cretinism Deficiency
• Calcium - Healthy Bones and Teeth
• Potassium - Nerve impulses conduction
• Iron - Haemoglobin

Describe the functions of retinol, Cyanobalamin, ascorbic acid, Calciferol, and Tocopherol

• Retinol - Photochemical reactions in Retina
• Cyanobalamin - Control of metabolism
• Calciferol - Absorption and metabolism of calcium and phosphorus
• Ascorbic Acid - Intercellular formation
• Tocopherol - Possible function in gametes

Discuss the importance of fibre in the diet

• Essential for effective working of alimentary canal
• Gives bulk to Urea
• Absorbing water and making contents more solid
• Stimulates peristalsis

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