1. Translation

2. The players mRNA- carries codon message from DNA to ribosome
tRNA- translates codons into amino acids
Ribosome- bonds amino acids together

3. Transfer RNA ~80 nucleotides long Anticodon pairs with mRNA codon
Amino acid on 3` end
Amino Acid is added
to growing polypeptide
tRNA is reuseable

4. Amino Acids Aminoacytl-tRNA synthetase enzyme that binds tRNA to
amino acid specificity
Endergonic reaction
Some tRNAs can bind to
more than one codon wobble
in third nucleotide
UCA, UCG, UCC, UCU
all code for Leucine

5. Ribosomes Large and small subunit Subunits attach when mRNA is present
rRNA and Proteins
Subunits attach when mRNA is present
Prokaryotic and
eukaryotic ribosomes
contain different
proteins
Antibiotics inactivate
prokaryotic ribosomes
without harming eukaryotic

6. Ribosome function P- site  holds tRNA w/ polypeptide
A-site  holds tRNA w/ next amino acid
E-site  tRNA exit site

7. Building Proteins
3 Stages
Initiation
Elongation
Termination

8. Initiation Methionone binds to AUG codon of mRNA
Signals start of translation
Establishes reading frame
Large subunit attaches to small subunit
Initiator tRNA ends up in P site

9. Elongation

10. Termination Release factor- protein that binds to stop codon
Water molecule is added instead of amino acid hydrolyzes polypeptide from tRNA

11. Polyribosomes A ribosome builds a protein in less than a minute
Many ribosomes work on the same mRNA

12. Protein folding Three levels of protein structure
Post-translational modifications
Remove nucleotides
Cut polypeptide
Assemble multiple chains

13. Protein shipping Free and bound ribosomes
Free make proteins used in the cytoplasm
Bound make proteins excreted from cell or used in endomembrane system
Signal peptide sends protein to ER