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Vitamins and minerals
Below is a table showing the recommended daily allowances of vitamins and minerals.
http://www.althealth.co.uk/services/info/misc/rda1.php)
Task 2
Carbohydrates mostly function as our energy source. They provide energy for not only sustained aerobic exercise, but also for high-intensity exercise like weightlifting. Thus, they provide necessary energy to exercise and build muscle. They are also metabolic primers necessary for the burning of fat.
Carbohydrates are made up of carbon, hydrogen and oxygen, hence the name. Carbo relates to carbon, and hydrate means to gain water, which consists of hydrogen and oxygen. In fact, carbohydrates contain hydrogen and oxygen in exactly the same ration as water. The ratio is always two hydrogen atoms to one oxygen atom. An example is a glucose molecule, which comprises six carbon atoms. Twelve hydrogen atoms and six oxygen atoms- (C6H12O6)
(Stafford-Brown et al)
Glucose ring (www.chelt.ac.uk/gdn/origins/ life/ch1_2.htm)
Monosaccharides are known as simple sugars. Their structure consists of a single chain or ring, with between three and seven carbon atoms. Glucose, the major source of energy in the body is a monosaccharide, and so is fructose, which has the same formula (C6H12O6) as glucose but is arranged in a different order.
(Adopted from Stafford-Brown et al)
Hooking two monosaccharides together forms a more complex sugar, such as the union of glucose and fructose to give sucrose, or common table sugar. This is done by a Glycosidic bond – “A type of chemical bond that joins two simple sugars via an oxygen atom. The bond may be either above the plane of the ring as in a beta glycosidic bond or below the plane as in an alpha glycosidic linkage.” (Quote from )
It can also be called a dehydration synthesis. This name is derived from the fact that a water molecule is lost from the two chemicals that join together. The reverse of this process is called hydrolysis. For example when you drink a sweet cup of tea the sucrose is broken down by acids in the stomach to form glucose and fructose.
Condensation Reaction resulting in Glycosidic Bonds in Maltose (http://www.sparknotes.com/nutrition/carbohydrates/section1.html)
Compounds such as sucrose are called Disaccharides (two sugars). Both monosaccharides and disaccharides are soluble in water.
Dehydration synthesis also results in the formation of polysaccharides. These are long chains made up of three or more monosaccharide. “poly” means many, and polysaccharides are examples of polymers being a chainlike molecule made up of sub-units or smaller molecules. Because of their size, these are often times not soluble in water. Many biologically important compounds such as starches and cellulose are Polysaccharides. Starches are used by plants and glycogen by animals, to store energy in their numerous carbon-hydrogen bonds, while cellulose is an important compound that adds strength and stiffness to a plant's cell wall.
Task 3
Protein is responsible for the building and repair of muscle. It is only used as an energy source when there are not enough carbohydrates available for normal metabolic function. If you do not eat enough protein, your body doesn't have enough amino acids to create muscle and your muscles could degenerate. Too much protein, like all calories, will be stored as fat.
Proteins structures are somewhat more complex than carbohydrates’. Like carbohydrates they always contain carbon, hydrogen and oxygen, but they also contain nitrogen. In addition, some proteins contain sulphur and phosphorous.
Proteins are made up of amino acids. There are 20 familiar amino acids. When amino acids are joined together, such as in a protein, the join or bond is called a peptide bond, and the process is another example of dehydration synthesis. A compound consisting of two amino acids joined together is called a dipeptide. A tripeptide is made up of three amino acids. A peptide of more than ten amino acids is called a polypeptide.
(Stafford-Brown et al)
(www.rothamsted.bbsrc.ac.uk/.../ guide/aa.htm)
Proteins have many functions in the body, and most are involved in helping the body perform physical activity. There are structural proteins, which actually form various parts of the body such as skin and hair. Skeletal muscles are largely made up of actin and myosin, which are contractile proteins – allow muscles to contract, which in turn produces movement. Haemoglobin is an example of transport protein, it’s used to transport carbon and oxygen in the blood. (Stafford-Brown et al)
Some Human Protein Hormones:
- Insulin (causes cells to take in sugar from the bloodstream)
- Glucagon (causes cells to release sugar into the bloodstream)
- ADH (Anti-Diruetic Hormone)
- TSH (Thyroid-Stimulating Hormone)
- hGH (Human Growth Hormone)
Another function of proteins include acting as enzymes, (which control chemical reactions) and proctecting the body in terms of antibodies.
Task 4
Fat is necessary to the diet because it is used as a backup energy source for the body and protects vital organs. If you do not eat enough fat, your body will try to store what it presently has (in case of emergency!) Too little fat has also been shown to cause heart problems and kidney stones.
It takes 20% more energy to convert carbohydrates and protein than it does dietary fat to body fat. In other words, fat is too efficiently stored. A diet too high in fat can cause sluggishness and limit endurance. It is also easy to eat too much fat because it weighs in at 9 calories per gram as compared to 4 calories in carbohydrates and protein.
Lipids are carbon compounds that do not dissolve in water. They are distinguished from other macromolecules by characteristic hydrocarbon chains—long strings of carbon molecules with hydrogen attached. Such chains do not dissolve well in water because they are nonpolar.
Triglycerides consist of three long hydrocarbon chains known as fatty acids attached to each other by a molecule called glycerol.
(http://cgi.sparknotes.com)
Because they include three fatty acids, fats and oils are also known as triglycerides. Glycerol and each fatty acid chain are joined to each other by dehydration synthesis.
Some fats are saturated, while others are unsaturated .These terms refer to the presence or absence of double bonds in the fatty acids of fats. Saturated fats have no double bonds, whereas unsaturated Fats contain one or more such bonds. In general, plant fats are unsaturated and animal fats are saturated.
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Task 5
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Pure water is practically colourless and it has no taste or smell. The chemical formula of water is H2O. There is one atom of oxygen attached to two hydrogen atoms. The two hydrogen atoms are bound to one side of the oxygen atom. This results in the water molecule having a positive charge on the side with the hydrogen atoms, leaving the other side of the oxygen atom negatively charged. Since opposed electrical charges attract each other, water molecules also have a tendency to attract each other, which is why water forms drops. (Stafford-Brown et al)
Water can be found in three states
The human body is two-thirds water. Water is an essential nutrient that is involved in every function of the body. It helps transport nutrients and waste products in and out of cells. It is necessary for all digestive, absorption, circulatory, and excretory functions, as well as for the utilization of the water-soluble vitamins. It is also needed for the maintenance of proper body temperature.
BIBIOGRAPHY
Stafford-Brown, J. Rea, S. Chance, J. sport and exercise science 2003 hodder and Stoughton
Ultra-fit magazine
www.weightlossresources.co.uk
