Chapter 7 - Animal nutrition

DIET

• Most animals need seven types of nutrient in their diet;
  • carbohydrates
  • proteins
  • fats
  • vitamins
  • minerals
  • water
  • fibre

• A diet which contains all of these things, in the correct amounts and proportions, is called a balanced diet. 
• Food is needed for energy and nutrient supply. 
• Vitamins are organic substances which are only needed in tiny amounts. 
• Minerals are inorganic substances, which are only needed in small amounts. 
• Fibre helps to keep the alimentary canal working properly. 
• peristalsis= when food moves along the alimentary canal because of the muscles contracting and relaxing, squeezing it along. 
• saturated fat= fat found in animal foods.
• coronary heart disease= when plaque and fatty deposists build up inside the coronary arteries. These can cause a blood clot, which results in a heart attack. 
• kwashiorkor= malnutrition caused by the lack of protein in the diet. 
• marasmus= malnutrition caused by severe shortage of energy in the diet. 

DIGESTION

• alimentary canal= long tube running from one end of a mammal's body to the other. 

• Amylase breaks down starch. Simple sugars are produced.
• Protease breaks down protein. Amino aicds are produced.
• Lipase breaks down fat. Fatty acids and glycerol are produced. 

• mechanical digestion= the breakdown of food into smaller pieces without chemical change due to the food molecules.
• chemical digestion= the breakdown of large insoluble molecules into small soluble molecules. 

• ingestion= taking of substances, e.g. food and drink, into the body through the mouth. 
• digestion= large, insoluble molecules of food are broken down to small molecules.
• absorption= the movement of small food molecules and ions through the wall of the intestine into the blood. 
• egestion= the passing out of food that has not been digested or absorbed, as faeces, through the anus. 

TEETH

• The root of the tooth is embedded in the gum. 
• The part of the tooth which can be seen is the crown. 
• The crown is covered by enamel. Enamel is the hardest substance made by animals; however, it can be dissolved by acids.
• Dentine is a layer of like-bone under enamel. It is quite hard.
• The pulp cavity is in the middle of the tooth. It contains nerves and blood vessels; these supply the cytoplasm in the dentine with food and oxygen. 
• Cement covers…