Nucleic Acids

Made up of 3 components:

• Phosphate group
• Pentose sugar (deoxyribose or ribose)
• Organic nitrogenous base

DNA is found in chromatin in nucleus

• Double stranded polymer 
• Forms double helix
• Pentose sugar is deoxyribose

Nucleotides joined together by condensation reactions between phosphate group of one and sugar group of another - forms a sugar phosphate bond known as the sugar phosphate backbone

Strands run anti-parallel to each other (5 prime end and 3 prime end)

DNA is more stable - can survive outside cell

Functions

• Replication
• Protein synthesis

• Single stranded polymer
• Contains ribose pentose sugar

3 types of RNA

• mRNA (messenger) - helix structure - carries genetic code from DNA to ribosomes in cytoplasm
• rRNA (ribosomal) - found in cytoplasm and is a large molecule - forms ribosomes
• tRNA (transfer) - single stranded molecule - forms a clover leaf structure - cytosine-cytsoine-adenine sequence forms at one end of molecule (anticodon) - transports amino acids to ribosome so they can be synthesised

There are 5 bases: adenine, guanine, cytosine, thymine, uracil

In DNA

• Adenine pairs with thymine - 2 hydrogen bonds
• Guanine pairs with cytosine - 3 hydrogen bonds

In RNA

• Adenine
• Guanine
• Cytosine
• Uracil