TwoOldGuys™ Study Guides
BI-122 Biology
Protein Synthesis

Protein primary structure

Peptide bond

Ribosome

Small Half

Large Half

functional

note: assembled protein is (always?) released in inactive form
and must be converted to active form by enzymatic action:

rRNA


tRNA

Codons

Relatively small RNA's can serve to transfer AA's to the ribosome for assembly into polypeptide sequence. These are transfer RNA [or tRNA] which are chemically bonded to the Amino Acid, and present an RNA sequence to be read by the rRNA.

1-digit code codes for only 4 objects

A G U C



2-digit code codes for 16 objects

AA GA UA CA
AG GG UG CG
AU GU UU CU
AC GC UC CC







3-digit is minimum required to code for 22 objects

Genetic Codons based on tRNA
Official
Dr. LaFrance
Secret Decoder Ring
1st
5'-end
2nd 3rd
3'-end
A G U C
A AAA
Phe
AGA
Ser
AUA
Tyr
ACA
Cys
A
AAG
Phe
AGG
Ser
AUG
Tyr
ACG
Cys
G
AAU
Leu
AGU
Ser
AUU
END
ACU
END
U
AAC
Leu
AGC
Ser
AUC
END
ACC
Trp
C
G GAA
Leu
GGA
Pro
GUA
His
GCA
Arg
A
GAG
Leu
GGG
Pro
GUG
His
GCG
Arg
G
GAU
Leu
GGU
Pro
GUU
Gln
GCU
Arg
U
GAC
Leu
GGC
Pro
GUC
Gln
GCC
Arg
C
U UAA
Ile
UGA
Thr
UUA
Asn
UCA
Ser
A
UAG
Ile
UGG
Thr
UUG
Asn
UCG
Ser
G
UAU
Ile
UGU
Thr
UUU
Lys
UCU
Arg
U
UAC
Met
UGC
Thr
UUC
Lys
UCC
Arg
C
C CAA
Val
CGA
Ala
CUA
Asp
CCA
Gly
A
CAG
Val
CGG
Ala
CUG
Asp
CCG
Gly
G
CAU
Val
CGU
Ala
CUU
Glu
CCU
Gly
U
CAC
Val
CGC
Ala
CUC
Glu
CCC
Gly
C



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© 2004-2005 TwoOldGuys ™

revised 19 aug 2006