Components of Food

Vitamins

Two Groups: Water soluble (B complex & C) and Fat soluble (A, D, E & K).

                       VITAMIN C Also called absorbic acid found in citrus fruits, e.g. oranges, blackcurrants, kiwis. helps make connective tissue deficiency disease = scurvy

               VITAMIN D also called calciferol found in milk, egg yolk, cod liver oil also made by the skin when exposed to sunlight it's function is to make healthy bones deficiency disease = rickets in children, osteomalacia in adults

Minerals

There are lots of different types needed in small quantities.

                   CALCIUM (Ca) found in milk, cheese, hard water needed for healthy bones & teeth

                IRON (Fe) found in red meat, liver, green veg needed to make haemoglobin in red blood cells, which carries oxygen around the body

Minerals are also needed by plants. They are absorbed in water from the soil by active transport.  Ex.1: Calcium is needed to make the middle lamella between cell walls. Ex.2: Magnesium (Mg) is needed to make chlorophyll

                                                     Food & NutritionFunctions: to give energy to allow growth & repair to prevent deficiency diseases

Components: Carbohydrates Lipids Proteins Minerals Vitamins Water

                                                                           CarbohydratesSUGARS: dissolves in water found in biscuits, sweets, cakes & juices sweet to taste function = quick release energy (17kj per gram) made of mono- and di- saccharides STARCH: does not dissolve in water found in potatoes, bread, rice & pasta not sweet to taste function = slow release energy (17kj per gram) made up of polysaccharides

Excess carbohydrates in the diet are converted to fat and stored under the skin & around the organs.

                                                                           LipidsELEMENTS: Carbon, Hydrogen & OxygenBASIC UNIT: 3 fatty acids joined to a glycerol. Phosolipids = have a phosphate attached instead of one of the fatty acids.SOURCES: butter, oil, chips, crisps, red meat.FUNCTIONS: provides 38kj of energy per gram. Excess is stored & used in insulation.If it's solid at room temperature = fat.If it's liquid at room temperature = oil.UNIT OF FAT: 

PHOSPHOLIPID:

                                                                      Proteins Made up of Carbon, Hydrogen, Oxygen and Nitrogen. Sometimes Sulphur. BASIC UNIT: amino acids (over 20 different types). Together, they from Peptides (less than 20 amino acids). Polypeptides = 20-200 amino acids. Proteins = greater than 200 amino acids.SOURCES: meat, fish, egg, nuts & pulse.FUNCTIONS:  to make fibrous protein (little/no folding), e.g. hair, nails, muscles & keratin to make globular protein (folding), e.g. enzymes & hormones

We cannot store proteins in the body. Instead, they are de-aminated in the liver, i.e. the amine group is taken away & made into urea, which is excreted in the urine.

Minerals & Vitamins

Food & Nutrition

Carbohydrates

Lipids & Proteins