Biological Molecules

Biological Molecules

Carbohydrates

  • Carbohydrates are energy-providing nutrients composed of carbon, hydrogen, and oxygen.
  • They can be classified into three main types: monosaccharides, disaccharides, and polysaccharides.
  • Monosaccharides are the simplest form of carbohydrate like glucose and fructose.
  • Two monosaccharides join to form a disaccharide such as sucrose.
  • Hundreds or thousands of monosaccharides can combine to form polysaccharides such as starch and cellulose.

Lipids

  • Lipids are known as fats and oils, composed of carbon, hydrogen, and a small amount of oxygen.
  • They function as a long-term energy store, insulators against heat loss and a protective layer around delicate organs.
  • Lipids are classified into two types: saturated and unsaturated lipids.
  • Saturated lipids contain only single bonds between carbon atoms, while unsaturated lipids contain at least one carbon-carbon double bond.

Proteins

  • Proteins are large complex molecules made up of amino acids, composed of carbon, hydrogen, oxygen, and nitrogen.
  • They play a vital role in structural support, transport, enzymes, antibodies and hormones.
  • The shape and function of a protein is determined by its specific arrangement of amino acids, which is coded by DNA.

Nucleic Acids

  • Nucleic acids are composed of nucleotides, which are made up of a sugar, a phosphate group, and a nitrogenous base.
  • Two main types of nucleic acids include DNA and RNA.
  • DNA or deoxyribonucleic acid contains all the instructions needed to build and maintain an organism.
  • RNA or ribonucleic acid translates the genetic information within DNA into proteins needed by the cell.

Enzymes

  • Enzymes are biological catalysts that speed up biochemical reactions in the cell.
  • They can do so without being consumed within the process.
  • The specific shape of an enzyme’s active site matches the shape of its substrate—the molecule it acts upon.
  • Each enzyme is specific as it will only catalyse one particular reaction. Each enzyme works best at its optimum temperature and pH.