The chemical compound that makes up DNA was first discovered by Friedrich Miescher in Germany around 1869. In 1953, Francis Crick and James Watson discovered that DNA is shaped like a ladder coiled into a ‘double helix’ shape.
The ‘sides’ of the ladder are a linked chain of alternating sugar and phosphate molecules.
different bases – adenine (A), thymine (T), guanine (G) and cytosine (C) and they link together in pairs (A with T, C with G) to form a rung. The order of the bases and rungs creates a kind of code for the DNA information.
Your body is made up of many different chemicals. An important group of chemicals is the proteins, which build your body and help it to function.
Each protein is formed from over 100 amino acids. There are 20 different types of amino acids that can be used to make proteins.
The code in the DNA ladder’s rungs is a recipe for building proteins. Tiny particles called ribosomes follow the DNA recipe to bind amino acids together and build proteins. Up to 1 000 rungs might be needed to hold the recipe for just one protein.
A group of rungs that carries the recipe for one protein is called a gene. When many genes are linked together in a DNA ‘ladder’, they will form a chromosome.
