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Introduction

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. ...read more.

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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. ...read more.

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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 1 Scientific Principles Assignment 1 ...read more.

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