DNA structure

Definitions

Genome - entire set of an organism’s genetic material
- Gene - section of DNA that codes for a particular sequence of amino acids - these sequences of amino acids form proteins
They control our characteristics as they code for proteins that play important roles in what our cells do
Polymer - molecule made from many repeating sub-units.
Nucleotides - the individual sub units of DNA

Structure of DNA

DNA is the genetic material found in the nucleus of the cell

It’s a polymer made up of 2 strands coiled around to make a double helix

DNA is a polymer. These individual sub-units of DNA are called nucleotides. Each nucleotide consists of a common sugar and phosphate group with one of four different bases attached to the sugar. The phosphate and sugar section of the nucleotides form the ‘backbone’ of the DNA strand (like the sides of a ladder) and the base pairs of each strand connect to form the rungs of the ladder

DNA is a polynucleotide - this means it is a polymer made up of many repeating subunits (monomers) known as nucleotides

There are 4 different nucleotides. They contain the same phosphate and deoxyribose sugar, but differ from each other in the base attached
There are four different bases: Adenine (A), Cytosine (C), Thymine (T) and Guanine (G)
The bases on each strand pair up with each other, holding the two strands of DNA in the double helix together and the bases always pair up in the same way: Adenine always pairs with Thymine (A-T) and Cytosine always pairs with Guanine (C-G) and is known as ‘complementary base pairing’
The complementary base pairs (A-T and C-G) pair up by forming weak hydrogen bonds with each other