1. One gene=one protein RNA & Protein Synthesis

2. Genetic Code -Universal All living organisms have the same four nucleotides- A, C, T, & G Central Dogma: Information flows from DNA RNA Protein RNA- Ribonucleic Acid 1 single chain of nucleotides RNA nucleotide- 3 parts Sugar- ribose Phosphate group Nitrogen base Adenine, Guanine, Cytosine, Uracil (instead of thymine) 3 types of RNA- mRNA; tRNA; rRNA Base pairing rules: A-U C-G

3. Triplet Code: There are 20 amino acids- 4 nucleotides must combine in groups of three. 3 ) 64 codons- (4 3 ) 61 code for amino acids. 3 are “stop codons” There is one start codon- AUG- methionine mRNA codon chart

4. Protein Synthesis- 2 main steps: 1. Transcription- occurs in nucleus mRNA( messenger RNA) is made from DNA. mRNA leaves the nucleus. DNA stays in the nucleus. 2. Translation- occurs at the ribosomes mRNA codons are translated into proteins.

5. Overview protein synthesis steps:

6. Details, details, details…….. Transcription- DNA molecule separates; one chain serves as a template. Base pair rules apply- A-U; C-G mRNA (after editing) goes to the ribosomes. Translation- mRNA is read by the ribosome. Translation begins with the start codon- AUG rRNA (ribosomal RNA) holds the mRNA in the ribosome. tRNA (transfer RNA) brings the correct amino acid. tRNA is T shaped: At one end- anticodon ( grouping of 3 RNA nucleotides) that matches up with the mRNA. (base pair rules) Opposite end -correct amino acid. Each tRNA is specific for only one amino acid.

7. Details continued…….. Amino acids combine to form a protein. The ribosome reads the mRNA code until a “stop” codon. Then the ribosome releases the mRNA and the protein is released. Very fast process- occurs in less than 1 minute. 3 nucleotide terms: DNA= triplet code mRNA= codon tRNA= anticodon Review: mRNA codon chart to determine the amino acids.

8. mRNA Codon Chart