1. NUCLEIC ACIDS Journey to the tiny world of DNA

2. Nucleic Acids  Organic molecules, include C, H, O, N and P elements.  Have various roles in metabolic activities.  Found in all living cells,  Even in viruses

3. Why so important?  Contain a life code that controls and regulates the activities of a cell.  Cell uses hereditary information to stay alive and to reproduce.

4. The Structure of a Nucleotide Phosphate (PO 4) 5C Sugar (ribose or deoxyribose) Nitrogenous bases (adenine, guanine, thymine,cytosine, uracil) 1 2 3 Nucleic acids are polymers of nucleotides. Phosphodiester bond Glycoside bond

7. DNA  Has two strands – double helix  One purine base always pairs with a pyrimidine.  Base pairing system  A – T and G – C  Number of complementary bases are A=T and G=C  Number of Pyrimidine = Purine

8. DNARNA It is double stranded (in some viruses, it is single) It is single stranded (but in some RNA viruses, it is double helix) 5C sugar is deoxyribose5C sugar is ribose Nitrogenous bases are A, G, C, T Nitrogenous bases are A, G, C, U Location: prokaryotes: in cytoplasm eukaryotes: nucleus, mitochondrion, chloroplast Location: prokaryotes: in cytoplasm eukaryotes: nucleus, cytoplasm mitochondrion, chloroplast, ribosome

9. 3 types of RNA  mRNA, tRNA, rRNA  mRNA (messenger RNA): carry information from the nucleus to the ribosomes in the cytoplasm. It’s synthesized in the nucleus over one strand of DNA and this is called transcription.

10. tRNA (transfer RNA):  Smaller than other RNAs  Carries free amino acids from cytoplasm to the ribosome where protein synthesis is going to take place.  There are 20 different tRNA molecules. WHY?

11. rRNA (ribosomal RNA)  Forms the main structure of the ribosomes.