1. VIDEO: NUCLEIC ACIDS NUCLEIC ACIDS

2. Overview: Nucleic Acids – include NUCLEOTIDES and POLYNUCLEOTIDES Many nucleic acids join together to form the macromolecules DEOXYRIBOSE NUCLEIC ACID (DNA) and RIBOSE NUCLEIC ACID (RNA) DNA contains the genetic information  stores the instructions to make amino acids and eventually proteins RNA is involved in transporting and processing of this genetic information DNADNA RNARNA

3. Nucleotide Structure: Made up of 3 smaller components:  A NITROGEN-CONTAINING BASE  A PENTOSE SUGAR  A PHOSPHATE GROUP

4. Nucleotide Structure Cont..... There are 5 different N-Containing bases in DNA and RNA: ADENINE, THYMINE, GUANINE, CYTOSINE and URACIL DNA – A, T, G, C RNA – A, U, G, C #note that Uracil replaces Thymine in RNA Nucleotides join together to form a chain:  DNA is composed of 2 strands in which the bases of one strand are hydrogen- bonded to the bases of another  The sugar-phosphate groups form the outer part of the molecule while the bases are orientated to the centre  The strands are twisted to form a DOUBLE HELIX

5. Nucleotides......... Complimentary Base Pairing The H-bonds can only form between certain bases: A – T G – C And vice versa. #Note In RNA, U replaces T *See previous diagram Antiparallel The end of a single strand that has the phosphate group is called the 5’ (5 prime) end. The other is the 3’ (3 prime) end The 2 connected strands run in opposite directions

6. Nucleotides.......... PURINES and PYRIMIDINES PURINES: Adenine & Guanine PYRIMIDINES: Cytosine, Thymine (DNA) & Uracil (RNA) Purines are 2-ringed bases Pyrimidines are single- ringed bases See previous diagram CODONS The nucleic acids act in 3s with each 3-letter coding for one amino acid Each 3-letter code is called a CODON ANTISENSE STRAND – the template side of the DNA that stores the information to be transcribed into mRNA SENSE STRAND – the opposite to the template side. Has the same nucleotide sequence as mRNA except T substitutes U