DNA

• DNA - deoxyribonucleic acid

  codes for the sequence of amino acids in primary structure of a protein, which then determines the 3D structure of functional protein

  all cells contain the genetic code and its passed to new cells

  DNA polymer forms a double helix
• DNA nucleotide

  the monomer that makes up DNA is called a nucleotide

  its made of a deoxyribose pentose sugar, a nitrogenous base, and a phosphate group

  the bases are guanine, cytosine, adenine and thymine

  G and C is 3 hydrogen bonds, T and A is 2 hydrogen bonds
• the polymers of nucleotides is called a polynucleotide

  its created via condensation reactions between the pentose sugar and the phosphate group creating a phosphodiester bond

  the DNA polymer is in pairs which are joined by hydrogen bonds which creates a double helix
• RNA is a polymer of a nucleotide formed of ribose sugar, nitrogenous bases and phosphate group

  the bases are adenine, guanine, cytosine and uracil

  its relatively short compared to DNA and single stranded
• RNA transfers the genetic code from DNA in the nucleus to ribosomes

  some RNA is combined with proteins to create ribosomes
• DNA relicpates with semi-conservative replication

  before a cell divides all the DNA must replicate to provide a copy for the new cell
• DNA helicase hydrolyses hydrogen bonds between bases, this causes double helix to unwind, this creates 2 template strands

  free floating DNA nucleotides in nucleus line up with complementary bases on template strands

  the adjacent nucleotides are joined forming phosphodieser bonds using DNA polymerase, works in 5’ to 3’ direction