DONCASTER COLLAGE
DEPARTMENT OF WELLBEING
BTEC NATIONAL AWARD/DIPLOMA IN SPORT AND EXERCISE SCIENCE
Scientific Principles - Assignment 1: Biological Chemicals
Student: Robert Foster
Date: 06/10/06 Tutor: Claire Rotherham
Biological Chemicals
In this assignment I am going to explain the structure and function of various nutrients and their use in the human body.
Proper nutrition is a key component for good heath and physical fitness. For best possible body function you must eat the right combination of nutrients they include:
Water (H2O)
The body is 70% water, although these values vary between 60% and 70%.
It provides an environment for all biochemical reactions in the body such as dissolves substances, transportation of nutrients and the lubrication of joints.
During exercise water maintains water balance and controls body temperature.
Failure to replace water can lead to dehydration which can cause serious problems such as heat exhaustion. The structure of water is below:
Carbohydrates
Carbohydrates exist mainly in the form of sugars and starches and are used as a major energy source. Carbohydrates are used to create glucose which can be used right away or stored to use later. Carbohydrates are broken into two categories, simple and complex. Sugars fall into the simple category, while starches and fibres are complex carbohydrates.
Carbohydrate molecules range from monosaccharide (single unit such as glucose) to disaccharides (two units such as sucrose) to polysaccharides (long chains, including starches, glycogen, fibres)
Monosaccharide
Monosaccharide is the simplest form of Carbohydrate. It contains carbon, hydrogen and oxygen (C6H12O6). Each molecule has twice as much hydrogen as carbon. A monosaccharide is a single unit such as one sugar.
The Structure is blow:
Disaccharides
Disaccharides are formed when two monosaccharide join together. This process of joining them is called dehydration synthesis. It is called dehydration synthesis because the water molecule is ...
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Carbohydrate molecules range from monosaccharide (single unit such as glucose) to disaccharides (two units such as sucrose) to polysaccharides (long chains, including starches, glycogen, fibres)
Monosaccharide
Monosaccharide is the simplest form of Carbohydrate. It contains carbon, hydrogen and oxygen (C6H12O6). Each molecule has twice as much hydrogen as carbon. A monosaccharide is a single unit such as one sugar.
The Structure is blow:
Disaccharides
Disaccharides are formed when two monosaccharide join together. This process of joining them is called dehydration synthesis. It is called dehydration synthesis because the water molecule is removed. The two glucose units are called a glycosidic bond.
The disaccharide structure (Sucrose, a common disaccharide) is below:
Polysaccharides
They are polymers made up of many monosaccharides joined together by glycosidic links. They are very large and are often branched molecules. They are insoluble in water, and have no sweet taste.
The Polysaccharide structure (starch) is blow
(Reference: www.biotopics.co.uk/as/glucose2.html)
Carbohydrates break down into glucose molecules. When used as energy, carbohydrates become fuel used to power muscle contraction. Muscle glycogen and blood glucose are the primary fuels during intense exercise. The body glycogen stores have an important role in sustaining high levels of aerobic exercise. A carbohydrate deficient diet affects both high intensity anaerobic and long aerobic exercise.
Proteins
Proteins are made of amino acids in a linear chain. They make up the major structural component of cells, antibodies (immunity system), enzymes and hormones. They are necessary for the body to build, repair and maintain muscle and other tissues.
Protein is mainly required after exercise. Protein may be needed in order to promote muscle adaptation during recovery from exercise in a couple of ways:
* Aiding in the repair of exercise-induced damage to muscle fibres
* Promoting training-induced adaptations in muscle fibres
* Facilitating the replenishment of depleted energy stores.
Peptide bond
A peptide bond is a chemical bond formed between two molecules when the carboxyl bond of one molecule reacts with the amino group of the other releasing a molecule of water. This is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids. Peptide bonds hold together the chains of amino acids in protein.
The structure of a peptide bond is below
(Reference: www.cryst.bbk.ac.uk/.../3_geometry/peptide1.html)
Vitamins
All vitamins perform different jobs within the body and work with the body's metabolism to increase energy levels. Vitamins are essential for metabolic reactions within the cell and for the maintenance of general health. They function primarily as catalysis during chemical reactions in the body, tissue building and for controlling the body's use of food. A total of 13 vitamins are known.
Minerals
Twenty elements are present in the body. Minerals and trace elements are used in many different body processes. Chlorine is essential for digestion, calcium and phosphorus is essential for strong bones and healthy teeth.
Fats
The body must have a certain level of fat intake. Fats are classified in two categories, saturated and unsaturated. Saturated fat is unhealthy and increases risk of health problems. Unsaturated fat is healthier, but if it is refined, it can become saturated fat. Nutritionists recommend that fats should constitute 25% of our dietary intake, but generally no more than 30 to 35% of this should be saturated fats. Fat- soluble vitamins are needed in the body as an heat insulator, energy source and a shock absorber. Fat stores can be found in the spinal canal, eye sockets and are situated around the main joints.
Lipids
Lipids are a class of hydrocarbon-containing organic compounds essential in providing stored energy and organ protection within a living organism. Lipids are categorized by the fact that they are soluble in non-polar solvents (such as ether and chloroform) and are relatively insoluble in water. Some lipids are used for energy storage, others serve as structural components of cellular membranes, and some are important hormones. Here are some lipid functions:
* Energy storage, lipids are effective at storing energy. They contain more energy than, for example, carbohydrates, because of their high carbon to oxygen ratio (less oxygen than in carbohydrates).
* Cell membrane structure Lipids in cell membrane structure (phospholipids) constitutes a barrier for the cell, controls membrane fluidity and controls the flow of material in and out of the cell
* Lipid hormones like steroids and eicosanoids - mediate communication between cells.
(reference of picture www.chemistryexplained.com/Kr-Ma/Lipids.html)
Assembly of lipids into more complex structures
At low concentrations lipids form monolayers, with the polar head group (represented as a circle) associating with the water, while the hydrophobic tails (represented as lines) associate with the air. As the concentration of lipid increases, either miscelles or bilayers form, depending upon the lipid and conditions.
Btec National Award Sport & Science Robert Foster
Scientific Principles Assignment 1