1.7 Summary

1.7 Summary (ESG4K)

• Cells are made up of organic and inorganic molecules which in turn are made up of atoms bonded together.
• Living organisms need to consume organic and inorganic compounds, which they break down for energy and use as building blocks for the components of life.
• Essential compounds are those that a living organism cannot build itself from other molecules, but must obtain from its environment.
• Plants may require a supply of inorganic nutrients through natural and non-natural fertilisers. An excess of non-natural fertilisers supplied to plants may result in eutrophication of rivers and lakes.
• Proteins, carbohydrates and fats are key organic molecules required for growth and survival of living organisms. All three are large molecules (polymers) made up of smaller molecules (monomers). We can test foods for the presence of these molecules.
• Each of these compounds has essential functions in living organisms, for example: fats (storage); proteins (growth); carbohydrates (energy); nucleic acids (store genetic information); vitamins (variety of functions in the body). An inadequate supply of these can result in diseases of malnutrition (e.g kwashiorkor, marasmus, scurvy, rickets etc).
• The class of proteins known as enzymes is important in speeding up chemical reactions in living organisms. Enzymes work under specific pH and temperature conditions known as `optimal conditions'. They may become denatured or deactivated under unfavourable conditions.
• The Recommended Dietary Allowance is a measure of how much of the various organic and inorganic nutrients we require in our diet. The specific allowance is different across age groups and sexes. It is a useful guide to maintaining a balanced diet.