• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Chemical compounds

Extracts from this document...


Chemical compounds are divided into two groups: * * Organic compounds are found in living organisms; they contain carbon and are combustible, eg carbohydrates, lipids, proteins, enzymes, vitamins, nucleic acids. * Inorganic compounds are found in the physical environment, eg water, carbon dioxide, mineral salts, inorganic acids, inorganic bases, salts. Water: * makes up 70% of living matter * is a solvent * has a high heat capacity * provides pressure to help keep shape * plays an important role in controlling human temperature * helps to split large molecules into smaller units * is a fluid medium for chemical reactions * transfers food materials and unabsorbed food wastes * * Carbohydrates (sugar and starch) contain C, H and O in a ration of two hydrogen to one oxygen. * Monosaccharides are single sugars which pass easily through semi-permeable membranes. There are four types: a) trioses C3H6O3 b) tetroses C4H8O4 c) pentoses C5H10O5 d) ...read more.


* are composed of C, H and O * have a ratio of H to O greater than 2 : 1 * are made up of glycerol and three fatty acids, which combine to form a fat or oil. In the process three water molecules are lost. If they rejoin, three water molecules are used. Fatty acids may be saturated or unsaturated. Glycerol has only one structure. The importance of lipids * make up part of the cell membranes * source of energy * help with absorption of vitamins A, D, E and K, which dissolve in fat * insulate the body * protect delicate organs, eg the eye, the heart * Proteins are made of C, H, O and N, and sometimes P, Fe and S. * Proteins contain N as well as C, H and O. * They are macromolecules which may contain P, S and Fe. * The basic units of proteins are amino acids. ...read more.


* Water soluble vitamins (B and C) * Vitamins combine with proteins to form enzymes. * Vitamins facilitate growth. * Vitamins develop the body's resistance to infections. * Deficiency of vitamins can cause diseases. A balanced diet maintains our health. It should include (in the right proportions): * carbohydrates * fats * proteins * vitamins * minerals * water * fibre No single food contains all of these things, so we need to eat a wide variety of food. * Malnutrition is incorrect nutrition. It can be either: * under-nutrition which is often caused by poverty or ignorance * over-nutrition which is eating too much of the wrong foods, such as sugars and fats * Both over- and under-nutrition can lead to serious health problems. * Marasmus is caused by lack of food, ie starvation. * Anorexia nervosa and bulimia nervosa are psychological conditions, where sufferers starve themselves of food. * High blood pressure, diabetes, heart disease and strokes are often found in overweight people who eat too much of the wrong foods. * High fibre diets provide fibre to act as roughage. Roughage helps peristalsis and prevents constipation. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work