1. DNA & RNA Notes
Unit 3

2. DNA: deoxyribonucleic acid
Genetic material; controls protein synthesis
DNA is a very long, thin molecule made up of nucleotides
Nucleotides are made up of three components:
1. 5 carbon sugar (deoxyribose in DNA)
2. phosphate group
3. nitrogenous base (ATCG)

3. Nitrogen Bases 1. Purines: two rings in structure -Adenine & Guanine
2. Pyrimidines: one ring
-Thymine & Cytosine
Base pairing occurs because adenine only bonds with thymine (A-T, T-A) and guanine only bonds with cytosine (C-G, G-C)
The nitrogen bases are held together with hydrogen bonds

4. DNA structure The sides of DNA are alternating sugars and phosphates
Strands condense into two long chains, which twists to form double helix
The order of the nucleotides in the center of DNA determines the traits a person has
The structure of DNA was determined by Watson & Crick
Animation:

5. RNA: ribonucleic acid
Nucleic acid which carries out protein synthesis (instructions from DNA)
Differences from DNA:
different sugar (ribose)
single strand
different base (no thymine, uracil instead)

6. Types of RNA
Messenger RNA: carries specific nucleotide sequence from nucleus to ribosome
Transfer RNA: picks up amino acid in cytoplasm and carries it to ribosome
Ribosomal RNA: found in ribosome, helps with formation of protein