Transcript Slide 1

Most of us
Coding
DNA
Jeremy
--------T G G ------
--------T G T ------
--------A C C ------
--------A C A ------
Messenger
RNA
--------U G G ------
--------U G U ------
Amino Acid
--------TRYPTOPHAN ------
Template
DNA
--------CYSTEINE ------
These guys also carry
mutations…apparently
--------T G T ----------T
G G ----
With point mutation G to T
ie a substitution
X Man Jeremy
Most of us
ISO
ISO
The offending
amino acid
LEU
LEU
ALA
ALA
CYS
TRY
ASP
ASP
ISO
ISO
PRO
PRO
Blimmin X Men
everywhere
What would be the result if the mutation
was a substitution of the G to a C ? -----T G G ----Most of us
ISO
ISO
LEU
LEU
ALA
ALA
?
TRY
Don’t forget to go:
…coding DNA
…template DNA
…mRNA
…A A
?
ASP
ISO
PRO
?
?
Original
TGG
Coding DNA
Template DNA
mRNA
Amino Acid
With MUTATION
TGC
ACC
ACG
UGG
UGC
Try
Cys
What the…
That is the same as Jeremy
How come?
There are 64 codons and 20 amino acids, that’s how come
The answer...
X Man Jeremy
Most of us
ISO
ISO
LEU
LEU
ALA
ALA
CYS
TRY
ASP
ASP
ISO
PRO
ISO
PRO
So no change then !!!
-----T G c ------ will still give CYS
What would be the result if the mutation was
a substitution of the G to an A ?
-----T G G -----Most of us
ISO
ISO
LEU
LEU
ALA
ALA
?
TRY
?
ASP
ISO
PRO
?
?
The answer...
Most of us
ISO
ISO
LEU
LEU
ALA
ALA
STOP!
TRY
ASP
ISO
PRO
A non-sense mutation.
It will make a very
short protein
Most likely with no
function