Glycosidic bond.
A glycosidic bond is formed between two monosaccharides as a result of dehidration synthesis. For example the linking of glucose and fructose to create sucrose. It is simply the dehydration reaction. A water molecule is extracted (causing a dehydration reaction), and a bond is formed, leaving an oxygen atom between the two monosaccharides.
Peptide bond
A peptide bond is a formed between two molecules, when the carboxyl group of one molecule reacts with the amino group of the other molecule and a water molecule is eliminated. This is a dehydration synthesis reaction (also known as a condensation reaction). The adding of water (amide hydrolysis) can break down a peptide bond. When a water molicule is added energy is spontaniously relised. However extreemly slowly. This prosess requires energy.
I am now goin to relate the structure of carbohydrates, protein, lipids and water to there function in the body.
There are two types of carbohydrate, complex and simple. Complex carbohydrates are long chains of glucose molecules wich must be broken down in to glucose befor they can be used in the body. These provide a long, slow relese of energy. This type of carbohydrate is good for endurance athletes for example long distance runners because it allows them to go at a steady speed for a longer period of time due to the long and slow release of energy.
The other type of carbohydrate is simple. Simple carbohydrates (or sugars) are a single ring consisting of between 3 and 7 carbon atoms because of this they can be broken down easliy and used for energy almost straight away. This however is a quick, short burst of energy. Befor athelets take part in a competition or match they should eat a meal containing complex carbohidrates about 3 hours befor. This allows the long chain of glucose to be broken down and used as energy during the sport. This type of energy is better than simple carbohydrates befor phisical activity because it doesn’t give the quick burst of energy and the low after it.
The structure of protein is more complex than that of a carbohydrate, they contain carbon hydrogen and oxygen the same as a carbohydrate, however these also contain nitrogen, some proteins can also contain sulphur and phosphorous. A protein is made up of a linear chain of amino acids. If these chains twist together they become a secondary structure. When a secondary structure becomes folded a more complex molecule is formed, this is called a tertiary structure. There are 20 amino acids in the body, when amino acids are joined together a peptide bond is formed. This is also an example of dehydration synthesis.
There are many different functions of proteins in the body; these are structural which are proteins that are designed to form the frame work of the body, for example keratin in the skin, hair and finger nails. Regulatory proteins are designed to function as hormones and regulate various physiological processes, for example insulin, which regulates blood sugar and is needed to prevent diabetes. Another type of protein is contractile; this allows muscle tissue to contract for example picking something up. Immunological are the proteins that act as anti bodies. These can be a natural source or and artificial one. Another function and type of protein are transport; these are used to transport vital substances around the body for example red blood cells that transport oxygen. Te final type of protein is catalytic; this type speeds up reactions in the body by acting as enzymes. Most of these are involved in helping the body to perform in physical exercise.
Regulatory protein helps to improve the performance of an athlete, an example of this type of protein is adrenalin, and this regulates the diameter of blood vessels and allows more blood to flow. This means that more oxygen is reaching the muscles being used which would allow an athlete to run faster. Protein would also be needed in high amounts for athletes that take part in weight lifting for example; contractile proteins allow muscle tissues to contract. When taking part in a sport such as weightlifting where muscles need to be tested and pushed to there maximum ability with out damaging.
Lipids contain more energy than carbohydrates, similarly to carbohydrates they are made of carbon hydrogen and oxygen. They are large compounds and are generally insoluble in water. There are many different types of lipids,
Phospholipids (an example being lecithin) are one type; this is a component of the cell membrane and found in the blood.
Fat is another type of lipid, these are a source of energy and help to insulate the body, a fat molecule is made up of fatty acid and glycerol.
Lipids provide more energy than carbohydrates for the same weight. This means that for endurance sports lipids are more effective for energy, this allows the athlete to perform at a high level increasing the duration and at a higher intensity.
Water effects exercise because it keeps performers hydrated and there functions working correctly. In every sport staying hydrated is extremely important for performance. In order for any athlete to perform to there best ability water is needed. During exercise a great deal of water is lost threw sweat. Staying hydrated allows any performer to exercise at a high intensity for a longer duration.
Bibliography
Websites
http://wikipedia.org/wiki/peptide_bonds
www.bbc.co.uk/health/healthy_living/nutrition
www.biocrawler.com/encyclopedia
www.mbarnes.dircon.co.uk/revision/chemestry
Books
Biological science 1 and 2, author DJ Taylor at all, published in 1997 (third edition) pages 83 and 93