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structure and function of the digestive system and nutrients

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Macronutrients Carbohydrates Carbohydrates have three main purposes: * To provide the body with energy * To allow the body to store and transport energy * To aid in bodily needs e.g. immune system, fertilization, pathogenesis, blood clotting, and development. The structure of carbohydrates consist of three elements, these are carbon, hydrogen and Oxygen. Carbohydrates can be broken down into two groups these are simple carbohydrates and complex carbohydrates. Simple Carbohydrates are also known as simple sugars and these include substances such as Sucrose (a combination of Glucose and Fructose). Other examples may include Lactose (a combination of Glucose and Galactose). Simple sugars may also be broken down into the amount of bonds they have; monosaccharide's consist of just one sugar, disaccharide consist of two sugars combined, and finally polysaccharides' consist of many sugars, usually three or more. These carbohydrates all gain quick access to bloodstream providing a slow, prolonged release of energy. Complex Carbohydrates come from starch and they are polymers made up of many monosaccharide's' joined together by glycosidic bonds. They are therefore very large, often branched, macromolecules. They tend to be solid, insoluble in water, and have no sweet taste. They go through the digestive system where they are broken down and transported to places in need of energy- it gives a steady release of energy over a prolonged period of time. There are many common sources of carbohydrates, some of the sources for simple carbohydrates are: * Sweets * Cakes * Chocolate * Biscuits * Jam Here are some examples of complex carbohydrates * Potatoes * Pasta * Spaghetti * Fruit * Whole Grain cereals e.g. ...read more.


Vitamin D is formed in the skin when it is exposed to sunlight Rickets Vitamin E Protects tissues against damage; promotes normal growth and development; helps in normal red blood cell formation Pure vegetable oils; wheatgerm, wholemeal bread and cereals, egg yoke, nuts sunflower seeds May cause muscular dystrophy Vitamin K Used by the liver for the formation of prothrombin Green vegetables Bleeding due to delayed clotting times caused by lack of clotting factors. Patients may show signs of bruising easily and have nosebleeds Minerals Minerals are essential for the maintenance of good health and the prevention of a number of diseases. Like vitamins, minerals cannot be manufactured in the body and without them we would not survive. Name Function Source Calcium Essential for strong bones and teeth. Also takes part in the body's immune system. Dairy Products Tofu Almonds, Brazil Nuts, Hazelnuts Iron Needed for healthy blood and muscles. It plays an essential role in the production of the body's white blood cells and in the activities of the immune system. Haem iron found in meat and offal (essentially the iron from blood and muscle). Non-haem iron derived from some plants, grains and nuts Magnesium Helps to regulate potassium and sodium levels within the body, which are involved in the control of blood pressure. Apricots, bananas, figs, prunes, raisins Brown rice, granary bread, wholemeal bread, wholewheat pasta, nuts, pulses, Courgettes, green leafy vegetables, okra, parsnips, peas, sweet corn Lean meat Milk, yoghurt. ...read more.


Soluble Fibre lowers cholesterol levels and controls blood sugar Sources of Insoluble Fibre include: * beans * brown rice * fruits with edible seeds * lentils * maize * oats * wheat bran, wholegrain breads, wholegrain cereals, wholemeal breads, wholemeal cereals, wholemeal pasta, wholewheat flour Sources of Soluble Fibre include: * apples * barley * citrus * guar gum * legumes * oats * pears * strawberries RDA's Recommended Daily Allowance (RDA) is the sufficient intake of a nutrient deemed correct for 97% - 98% of healthy individuals in each life-stage and gender. Nutrient Daily intake (g) Percentage of daily intake Protein Men- 55g Women- 45g 10%- 15 % Carbohydrates Men- 275g Women- 203g 47% - 49% Fats Men- 95g Women- 70g 30% - 35% Fibre Men- 18g Women- 18g 1% - 5% Vitamin Men Women A 0.7mg 0.6mg B1 1.0mg 0.8mg B2 1.3mg 1.1mg Nicin 19mg 15mg B6 1.4mg 1.2mg Pantothenic acid 5mg 5mg Folic acid 0.2mg 0.2mg Biotin 0.03mg 0.1mg B12 0.002mg 0.002mg C 40mg 40mg D 0.01mg 0.01mg E 10mg 8mg K 0.8mg 0.06mg Mineral Quantity Calcium 800mg Iodine 150mcg Iron 14mg Magnesium 300mg Phosphorus 800mg Zinc 15mg Estimated Average Requirement (EAR): This is an estimate of the average requirement for energy or a nutrient - approximately 50% of a group of people will require less, and 50% will require more. Safe intake: This is used where there is insufficient evidence to set an EAR. The safe intake is the amount judged to between the stages of deficiency and excess intake. There is no evidence stating that intakes above these levels are safe and in some instances they could have toxic effects. ...read more.

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