This document summarizes key aspects of genetic code and translation. It notes that the genetic code consists of 3 nucleotide codons that specify amino acids. There are 64 possible codons but only 20 amino acids, so the code is degenerate with multiple codons encoding the same amino acid. It discusses features like nearly universal code, lack of pauses, and the wobble hypothesis to explain third position degeneracy. Examples are given of codon tables and how changes can cause mutations.

1. POWERPOINT PRESENTATION BY:
SNEHA SUSAN MATHEW (15MSI0065)
*DEGENERACY IN
GENETIC CODE

2. *

3. *TRANSLATION
 THE PATHWAY OF PROTEIN
SYNTHESIS IS CALLED
TRANSLATION BECAUSE THE
LANGUAGE OF NUCLEOTIDE
SEQUENCE ON mRNA IS
TRANSLATED IN TO THE
LANGUAGE OF AMINO ACID
SEQUENCE.
 THE PROCESS OF
TRANSLATION REQUIRES A
GENETIC CODE, THROUGH
WHICH THE INFO CONTAINED
IN THE NUCLEIC ACID
SEQUENCE IS EXPRESSED TO
PRODUCE A SPECIFIC
SEQUENCE OF AMINO ACID.

4. *
 SET OF RULES BY
WHICH
INFORMATION
ENCODED WITHIN
GENETIC MATERIAL
IS TRANSLATED INTO
PROTEINS.
 TERM GIVEN BY
GEORGE GAMOW.

5. SALIENT FEATURES OF
GENETIC CODE

6. *
THREE ADJACENT
NITROGEN BASES
CONSTITUTE A CODON
WHICH SPECIFIES THE
PLACEMENT OF ONE
AMINO ACID IN A
POLYPEPTIDE.
1 CODON = 1 AMINO
ACID

7. *
*ONE CODON CODES FOR ONLY
ONE AMINO ACID.
*EXAMPLE: AUG CODES FOR
METHIONINE.

8. *
*THE CODE IS NEARLY UNIVERSAL.
*AUG – METHIONINE
*AUG -- VALINE
*FOR EXAMPLE: FROM BACTERIA
TO HUMANS UUU WOULD CODE
FOR PHENYLALANINE ( phe ).

9. *
*THE GENETIC CODE IS
CONTINOUS AND DOES NOT
POSSESS PAUSES AFTER THE
TRIPLETS.
*IF A NUCLEOTIDE IS ADDED OR
DELETED, THE WHOLE GENETIC
CODE WILL READ DIFFERENTLY.

10. THERE ARE 64
POSSIBLE
COMBINATIONS OF 3
LETTER NUCLEOTIDE
SEQUENCES .
61 REPRESENTS AMINO
ACIDS AND 3 ARE STOP
CODONS.
NIRENBERG AND HAR
GOBIND KHORANA
PREPARED THE
GENETIC CODON
TABLE FOR VARIOUS
AMINO ACID.

11. *CODON TABLE

12. *
*SOME AMINO ACIDS MAY BE INFLUENCED
BY MORE THAN ONE CODON.
*AMINO ACIDS ARE SPECIFIED BY TWO TO
SIX CODONS.
*EXAMPLE: phe – UUU, UUC
*Arginine- CGU,CGC,CGA,AGA,AGG.
*DEGENERACY RESULTS THERE ARE MORE
CODONS TO ENCODE 20 AMINO ACIDS.

13. *DEGENERACY
*GUU = VALINE GUA = VALINE
* GUC = VALINE GUG = VALINE

14. UUU: XYU
UUC: XYC
UUA: XYA
UUG: XYG

15. *IN DEGENERATE
CODONS,GENERALLY THE
FIRST TWO NITROGEN
BASES ARE SIMILAR
WHILE THE THIRD ONE IS
DIFFERENT.

16. *
*ACCORDING TO THIS HYPOTHESIS,
ONLY THE FIRST TWO BASES OF THE
CODON HAVE A PRECISE PAIRING WITH
THE BASES OF THE ANTICODON OF
mRNA WHILE THE PAIRING BETWEEN
THE THIRD BASES OF CODON AND
ANTICODON MAY WOBBLE(NON-
SPECIFIC).

17. Nucleotide
at 5' end of
anticodon
Nucleotide
at 3' end of
anticodon
G U or C
C G
A U
U A or G
I (indosine) A, U or C

18. *
*ANY CHANGE IN THE
IN THE GENETIC CODE
CAUSES MUTATION.

19. *
*AUG GUG AGC AGG ADDITION
*AUG GUG ACG CAG G

20. *THANKYOU