1. TRANSLATION
SBI 4UI – 5.4

2. Transportation mRNA exits the nucleus and enters the cytoplasm
mRNA can now begin translation

4. The Ribosome Recognize 5’ cap of mRNA In eukaryotes Binding with it
Consists of 2 subunits
The subunits clamp the mRNA
Moving in 5’ to 3’ direction
Adding an amino acid for each codon
Known as a reading frame

5. The Role of tRNA Amino acids must be delivered to the ribosome
To build polypeptide

6. tRNA structure Single-stranded nucleic acid
Looks like a cloverleaf
Recognition of mRNA is through complementary base pairing

7. (a) known as anticodon
Opposite end carries appropriate amino acid

8. Polypeptide Elongation
First codon is the start codon
AUG (methionine)
Ribosome has 2 sites for tRNA
A site – acceptor
P site – peptide

10. Polypeptide Elongation
tRNA carries methionine to P site
Next tRNA with required amino acid enters A site
Peptide bond occurs
Ribosome shifts one codon for next tRNA
Translocation

13. Termination of Protein Synthesis
Ribosome will reach one of three “stop” codons
UGA, UAG, UAA
Release factor protein
Releases polypeptide chain from ribosome
mRNA released from ribosome

14. Questions?

15. To Do
Section 5.4
Understanding Concepts #1-9