Animal Nutrition

• The seven nutrients in a diet are:

  • Carbohydrates
  • Proteins
  • Fats
  • Vitamins
  • Minerals
  • Water
  • Fibre
• Balanced diet: a diet which contains all the seven types of nutrient in the correct amounts and proportions.
• Carbohydrates: source of energy
• Proteins: Used for making new cells which are needed for growing and repairing damaged parts of the body.
• Fats: Used as a source of energy and for insulation.
• Vitamins: organic substances which are only needed in tiny amounts.
• If you don't have enough of a vitamin, you may get a deficiency disease.
• Minerals: inorganic substances which are needed only in small amounts.
• Fibre: helps to keep the alimentary working properly.
• 3 ways fibre helps:

  • helps in PERISTALSIS - when the muscles contract and relax to squeeze the food along the alimentary canal. 
  • prevents colon cancer
  • prevents constipation
• SCURVY: causes pain in joints and muscles and bleeding from gums and other places.
• SCURVY is caused by a lack of Vitamin C
• Vitamin C is needed to make stretchy protein called collagen, found in skin and other tissues; keeps tissues in good repair.
• RICKETS: the bones become soft and deformed; common in children who rarely go out into the sunshine
• RICKETS is caused by a lack of Vitamin D
• Vitamin D helps calcium to be absorbed, for making bones and teeth.
• Sources of Vitamin C:

  • citrus fruits
  • vegetables
• Sources of Vitamin D:

  • butter
  • egg yolk
  • sunlight
• BRITTLE BONES AND TEETH and POOR BLOOD CLOTTING is caused by a lack of Calcium
• Calcium is used in bones in teeth and in blood clotting.
• Sources of Calcium:

  • milk and other dairy products
  • bread
• ANAEMIA: there are not enough red blood cells so the tissues do not get enough oxygen delivered to them.
• ANAEMIA is caused by a lack of Iron
• Iron is used for making haemoglobin, the red pigment in blood which carries oxygen.
• Sources of Iron:

  • liver
  • red meat
  • egg yolk
  • dark green vegetables
• OBESITY: happens to people who take in more energy than they use up. It is being very fat.
• CORONARY HEART DISEASE: when fat deposits blocks the arteries which bring oxygen to the heart muscle. The deposits of fat can cause a blood clot, which results in heart attack. 
• MALNUTRITION: caused by not eating a balanced diet. This is because the nutrients a person is eating are not in the right proportions.
• Example of malnutrition:

  • KWASHIORKOR. This is caused by a lack of protein in diet. Children with kwashiorkor are always underweight for their age.
  • MARASMUS: a child has body weight much lower than normal. Results from lack of both protein and energy in the diet.
• 1. INGESTION: food is taken into the alimentary canal.
  2. DIGESTION: large, insoluble molecules of food are broken down to small molecules.
  3. ABSORPTION: the small molecules are absorbed into the blood.
  4. EGESTION: food which could not be digested or absorbed is removed from the body. 
• Ingestion: taking substances (food, drink) into the body through the mouth.
• Digestion: the breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes.
• Mechanical digestion: the breakdown of food into smaller pieces without chemical change to the food molecules. 
• Chemical digestion: the breakdown of large insoluble molecules into small soluble molecules.
• Absorption: the movement of digested food molecules through the wall of the intestine into the blood.
• Assimilation: the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells
• Egestion: passing out of food that has not been digested, as faeces, through the anus.
• STARCH:

  Enzyme - amylase

  Small molecules - simple sugars
• PROTEINS:

  Enzyme - protease

  Small molecules - amino acids
• FATS:

  Enzyme - lipase

  Small molecules - fatty acids and glycerol