- Most animals need seven types of nutrient in their diet;
- 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.
- Fiber 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 deposits 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.
- 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.
- 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 the root of the tooth.
- Most mammals have four kinds of teeth - incisors, canines, premolars and molars.
- Incisors are sharp-edged, chisel-shaped teeth at the front of the mouth; they are used for biting off pieces of food.
- Canines are more pointed teeth, at either side of the incisors.
- Premolars and molars are the large teeth towards the back of the mouth; they are used for chewing food.
- If sugar is left on the teeth, bacteria in the plaque will feed on it. They use it in respiration, changing it into acid.
- There are several easy things which you can do to keep you teeth and gums healthy and free from pain:
- don't eat too much sugar
- use fluoride toothpaste regularly
- make regular visits to the dentist.
The end of part I ! (remember to read part II)
Drafted by Gina (Biology)