CIVIL ENGINEERING

1. NAME: AYAN GHOSH
SUB:BIOLOGY
TOPIC:GENETIC CODE AND
ITS PROPERTIES
SUBJECT CODE:CE(BS)301
DEPT.:CE
YEAR: 2ND
SEM: 3RD
ROLL NO.: 26901321001
MODERN
INSTITUTE OF
ENGINEERING &
TECHNOLOGY
{DEDICATED TO EXCELLENCE}

2. INDEX
 INTRODUCTION
 GENETIC CODE
 WOOBBLE HYPOTHYESIS
 PROPERTIES
 CONCLUSION
 REFERENCE
 ACKNOWLEDGEMENT

3. INTRODUCTION
 What is genetic
code?
 Genetic code is the sequence
of nucleotides in DNA and RNA
that determines the amino acid
sequence of proteins.

4. CODON
 It is a sequence of three nucleotides which
together from a unit of genetic code in a DNA or
RNA molecule. In short codons are the triplet base
of nucleotide.
 The nucleotides are adenine(A), cytosine(C),
guanine(G),thymine (T)and uracil(U)
 There are only 20 types of amino acid.
 There are 64 codons and in those codons 61 are
sense codons and 3 are non-sense codons which
are UAA,UGA,UAG.

5.  Here we see how the
codons are made and
which codes whom.

6. WOBBLE HYPOTHYESIS
There are more than one codon for
one amino acid .This is called
degeneracy of genetic codons . To
explain the possible cause of
degeneracy of codons ,in 1966
Francis Crick proposed the ”
Wobble Hypothesis”.
 The Wobble hypothesis proposes
that normal base pairing can
occur between nitrogen bases in
position 1 and 2 of the codon
and the corresponding bases(3
and 2 )in the anticodon.

7. PROPERTIESOF GENETIC CODE
 Universality:-The same genetic code is seen valid for all the
organism i.e. they are universal.
 Triplet code:- A codon or a code word is defined as a group of
bases that specify an amino acid. There is strong evidence
,which proves that a sequence of three nucleotides for an
amino acid in the protein , i.e., the code is triplet.
 Comma less code:- No room for punctuation in between
which indicates that every codon is adjacent to the previous
one with out any nucleotides between them.

8.  Non-overlapping code:- The code is read sequentially in
a group of three and a nucleotide which become a
part of triplet never becomes part of the next triplet.
 Degenerate code:- Every amino acid except
tryptophan (UGG) and methionine (AUG) is coded by
various codons, i.e., a few codons are synonyms and
this aspect is known as the degeneracy of genetic
code. For instance, UGA codes for tryptophan in
yeast mitochondria.
 Polarity:-Each triplet is read from 5’ → 3’ direction and
the beginning base is 5’ followed by the base in the
middle then the last base which is 3’. This implies that
the codons have a fixed polarity and if the codon is
read in the reverse direction, the base sequence of the
codon would reverse and would specify two different
proteins.

9. CONCLUSION
 FROM THE WHOLE DISCUSSION WE
CAN CONCLUDE THAT GENETIC
CODE IS ONE OF THE MOST
IMPORTANT PART OF MAKING THE
STRUCTURES OF DNA & RNA .

10. ACKNOWLEDGEMENT
 I would like to express my special thanks of
gratitude to my teacher Ipsita Das who gave
a golden opportunity to do this wonder full
PPT on the topic “ Genetic codes and its
properties” which also helped me to gather
more knowledge on it.