1. Part 5 Translation

2. Central Dogma
Process of DNA RNA protein

3. Gene expression
Fig

4. Translation: mRNA and the Genetic Code
Codon  3 sequential Nitrogen bases in mRNA
64 different mRNA codons
61 code for different amino acids
Redundant code (some AA have different codons)
Protection against mutations
Stop codons signal polypeptide termination
Start codon  AUG (methionine) starts translation

5. Messenger RNA codons & their AA

7. Transfer RNA Transfer RNA (tRNA)
tRNA transports amino acids to ribosomes
Amino acid binds to one end, the opposite end has an anticodon
Order of mRNA codons determines the order in which tRNA brings in amino acids

8. Ribosomes & rRNA Ribosome
Made in nucleolus  2 “subunits”
Small subunit  1 rRNA + proteins
Large subunit  2 rRNA + proteins + enzymes
Binding site for mRNA and for 2 tRNAs
Polyribosome  Several ribosomes may move along the same mRNA
Multiple copies of polypeptide made at same time

9. Translation: Initiation, Elongation, Termination
Small subunit attaches to mRNA at start codon
Anticodon binds to start codon
Large ribosomal subunit joins to the small subunit

10. Translation: Initiation, Elongation, Termination
Amino acids added one at a time
tRNA breaks away, and the ribosome moves forward one codon
Movement of the ribosome is called translocation

11. Translation: Initiation, Elongation, Termination
Occurs at a stop codon
Polypeptide is cleaved by an enzyme from the last tRNA
Ribosome dissociates into 2 subunits

12. Protein synthesis
Fig

13. Central Dogma Process of DNA RNA proteins
Proteins express traits (turn on & off)!!

14. Learning Check! What are the types of RNA used during translation.
What does each type of RNA used in translation do?
What is the flow of genetic information? (How is DNA expressed)
If I have a DNA nucleotide sequence TAG, what would it’s mRNA codon be? It’s tRNA anticodon? And finally it’s associated amino acid?