DNA contains the genetic code and is located in the cell nucleus. It is a double-stranded molecule made up of nucleotides with a sugar (deoxyribose), phosphate group, and nitrogenous base. DNA replicates via a semi-conservative process where each new DNA molecule contains one original and one new strand. RNA is a single-stranded copy of DNA that carries instructions from DNA in the nucleus to the cytoplasm. There are three main types of RNA: mRNA, tRNA, and rRNA, which help in protein synthesis by carrying amino acids and combining with ribosomes.

1. DNA & Protein Synthesis

5. DNA O O=P-O O Phosphate Group N Nitrogenous base (A, T , G, C) CH2 O C 1 C 4 C 3 C 2 5 Sugar (deoxyribose)

6. DNA - double helix P P P O O O 1 2 3 4 5 5 3 3 5 P P P O O O 1 2 3 4 5 5 3 5 3 G C T A T A

10. Original DNA DNA unzips Each original strand grows a new strand

14. RNA O O=P-O O Phosphate Group N Nitrogenous base (A, U , G, C ) CH2 O C 1 C 4 C 3 C 2 5 Sugar (ribose)

15. T – A G – C U – A G – C Phos-phate Group Deoxyribose Sugar Nitro-gen Base Phos-phate Group Ribose Sugar Nitro-gen Base DNA RNA How many strands? 2 1 Nucleotide subunit Deoxyribose sugar Ribose sugar Bases ______ (T) Adenine (A) Guanine (G) Cytosine (C) ______ (U) Adenine (A) Guanine (G) Cytosine (C)