1.CARBOHYDRATES (1g = 16kJ) TEXTBOOK P301-305
These are compounds of carbon, hydrogen and oxygen.
Examples are starches and simple sugars such as glucose.
Provide most of the energy needed by the majority of human diets.
Carbohydrates can be divided into three groups:
A Monosaccharides – simple sugars which cannot be broken down into smaller units. Building blocks of carbohydrates. Examples – glucose, fructose.
Simple sugars can be joined together to form more complex sugars.
B Disaccharides – are composed of two monosaccharides joined together. Examples – maltose which is made up of two glucose units, sucrose (table sugar) which is made up a glucose and a fructose joined together. Also lactose (in milk)
C Polysaccharides – are composed of many monosaccharides joined together. Starch and cellulose are polysaccharides found in plants. Starch can be broken down by humans to glucose molecules however cellulose is not broken down (useful as fibre in the diet). Note: glycogen is a store of carbohydrate in muscles.
2. LIPIDS – FATS & OILS (1g = 37kJ) TEXTBOOK P305-308 Fats are compounds that contain carbon, oxygen and hydrogen like carbohydrates however they contain less oxygen. Oils are similar to fats except they are liquid at room temperature. Includes triglycerides and cholesterol.
3. PROTEINS (1g = 17kJ) TEXTBOOK P309-312 Proteins are large complex molecules which contain carbon, oxygen and hydrogen as well as some nitrogen, sulphur and phosphorous. Amino acids() are the building blocks. A deficiency causes Kwashiorkor.
4. WATER TEXTBOOK P323,324
Required in diet (food and drinks) to keep body hydrated and ensure metabolic chemicals are at appropriate concentrations.
5. VITAMINS TEXTBOOK P315-319
A group of organic compounds that