Nucleic acid structure (DNA/RNA)

DNA structure 

• DNA has a double helix structure. 
• This means that a DNA molecule is formed from two separate strands which wind around each other to form a spiral. 
• The strands are polynucleotides. 
• They're made up of lots of nucleotides jointed together in a long chain. 
• DNA molecules are really long and are coliled up very tightly. 

DNA nucleotide structure 

• A DNA nucleotide is made from a phosphate group, the pentose sugar deoxyribose and a nitrogen organic base. 
• Each DNA nucleotide has the same sugar and phosphate. 
• The base on each nucleotide can vary though. 
• There are four possible bases 
• Adenine (A)
• Thymine (T) 
• Cytosine (C)
• Guanine (G). 

Complementary base pairing 

• Two DNA polynucleotide strands join together by hydrogen bonds between the bases. 
• Each pase can…