1. From gene to protein DNA mRNA protein trait nucleus cytoplasmaa
From gene to protein
nucleus
cytoplasm
transcription
translation
DNA
mRNA
protein
ribosome
trait

2. from nucleic acid language to amino acid language
Translation
from nucleic acid language to amino acid language

3. How does mRNA code for proteins?
TACGCACATTTACGTACGCGG
DNA 4
ATCG
AUGCGUGUAAAUGCAUGCGCC
mRNA 4
AUCG ?
Met Arg Val Asn Ala Cys Ala
protein 20
How can you code for 20 amino acids with only 4 nucleotide bases (A,U,G,C)?

4. mRNA codes for proteins in triplets
TACGCACATTTACGTACGCGG
DNA
codon
AUGCGUGUAAAUGCAUGCGCC
mRNA
AUGCGUGUAAAUGCAUGCGCC
mRNA ?
Met Arg Val Asn Ala Cys Ala
protein

5. The code Code for ALL life! Code is redundant Start codon Stop codons
strongest support for a common origin for all life
Code is redundant
several codons for each amino acid
3rd base “wobble”
Why is the wobble good?
Start codon
AUG
methionine
Stop codons
UGA, UAA, UAG

6. How are the codons matched to amino acids?3 5
DNA
TACGCACATTTACGTACGCGG 5 3
mRNA
AUGCGUGUAAAUGCAUGCGCC
codon 3 5
UAC
Met
GCA
Arg
tRNA
CAU
Val
anti-codon
amino acid

7. From gene to protein DNA mRNA protein trait nucleus cytoplasmaa
From gene to protein
nucleus
cytoplasm
transcription
translation
DNA
mRNA
protein
ribosome
trait

8. Building a polypeptide1 2 3
Building a polypeptide
Initiation
brings together mRNA, ribosome subunits, initiator tRNA
Elongation
adding amino acids based on codon sequence
Termination
end codon
Leu
Val
release
factor
Ser
Met
Met
Met
Met
Leu
Leu
Leu
Ala
Trp
tRNA C A G U A C U A C G A C A C G A C A 5' U 5' U A C G A C 5' A A A U G C U G U A U G C U G A U A U G C U G A A U 5' A A U
mRNA A U G C U G 3' 3' 3' 3' A C C U G G U A A E P A 3'

9. Can you tell the story? RNA polymerase DNA amino acids exon intron
tRNA
pre-mRNA
5' GTP cap
mature mRNA
aminoacyl tRNA synthetase
poly-A tail 3'
large ribosomal subunit
polypeptide 5'
tRNA
small ribosomal subunit E P A
ribosome