Download anti-codon

Protein Synthesis
Building protein from DNA in cells
Takes code
on
basepai Converts
it to
rs
Turned
into
Review
Proteins - long chains of amino acids
Order of amino acids important because
• it determine the shape of protein
• which in turn determine the
function or job of protein
Protein
Differences w/ DNA
• Single strand of
nucleotides
• nucleotide URACIL
replaces thymine
Complimentary bases in RNA
1. cytosine & guanine
2. adenine & uracil
3 types of RNA in protein syn.
1. mRNA - messenger RNA
• Straight single strand of RNA
2 . tRNA - transfer RNA
• Club shaped - transport
amino acids
3. rRNA - ribosomal RNA
- help link amino acids together
3 steps protein synthesis
1. Transcription
- DNA  mRNA
2. Translation
- tRNA reads mRNA
3. Linking
- amino acids linked together
Step 1 - Transcription
code form DNA used to form mRNA
• in nucleus
• DNA unzipped
- base pairs read
• Complimentary RNA nucleotides form mRNA
Step 1 - Transcription
Original DNA
C A T T C A G A C
mRNA G U A A G U C U G
formed
codon
• Code is stored - groups of 3 nucleotide
basepairs - called a CODON
Step 2 - Translation
mRNA enters cytoplasm &
ribosomes read codons on mRNA
Step 2 - Translation
tRNA - carry amino acids
• has special region - ANTI-CODON
-- 3 nucleotides
• nucleotides
complimentary to
codons on mRNA
• determine amino acid tRNA carries
codon 1
codon 2 codon 3
mRNA G U A A G U C U G
tRNA C A U U C A G A C
anti-codon 1
anticodon 2
anticodon 3
Step 3 - Linking
Amino acids brought to ribosome
by tRNA - linked together
tRNA w/ complimentary anticodon - fits into ribosome
- drops off amino acid attached
& links to protein chain
codon 1
codon 2 codon 3
mRNA G U A A G U C U G
tRNA C A U U C A G A C
anti-codon 1
Amino Valine
acid
(Val)
anticodon 2
anticodon 3
Serine
(Ser)
Leucine
(Leu)
• STOP codon - on mRNA stops linking amno acids
• START codon - start linking
amino acids