This presentation discusses the genetic code and how it translates DNA and RNA sequences into proteins. The genetic code is universal across all living organisms and consists of 64 codons composed of 3 nucleotides that correspond to 20 amino acids. Codons are classified as sense codons, which code for amino acids, or signal codons like initiation and termination codons. Anticodons on tRNAs pair with mRNA codons to recognize and translate the codons. The genetic code is non-overlapping, degenerate, and Francis Crick's wobble hypothesis explains the pattern of degeneracy by proposing the third position in the anticodon is not as specific.

1. • Presentation on
Genetic Code
Institute of Agriculture Sciences
Presented by:-
UTTAM KUMAR PATEL
B.Sc. Agriculture (1st Year)

2. What is Genetic Code ?
• The Genetic Code is the set of rules
by which information encoded in
genetic material (DNA or RNA
sequences) is translated into
proteins by living cells.
• The letters A, G, T and C correspond
to the nucleotides found in DNA.
They are organized into codons

3. Codons & Its Types
 Genetic code is a Dictionary consists of
“Genetic words” called CODONS.
• Each codon consists of
three bases (triplet).
• There are 64 codons.
• 61 codons code for 20
amino acids found in
protein.
• 3 codons do not code for
any amino acids.

4. Sense codon:
The codon that code
for amino acid are
called sense codon.
Signal codon:
Those codons that code for signal
during protein synthesis are
called signal codons.
For Example: AUG, UAA, UAG &
UGA.
There are Two types of signal
codons.
• Terminating Codons
• UAA, UAG & UGA are termination codons or non-sense
codons & are often referred to as amber, ochre & opal
codons.
• Initiating codon
• AUG is the initiation codon. It codes for the first amino
acid in all proteins.
• At the starting point it codes for methionine in
eukaryotes & formyl methionine in prokaryotes.
Types

5. Anticodon
• The base sequence of tRNA
which pairs with codon of
mRNA during translation is
called anticodon.
• The codon of the mRNA is
recognized by the anticodon
of tRNA.
• They pair with each other in
antiparallel direction (5’- 3’
of mRNA with 3’- 5’of tRNA).

6. Properties of Genetic Code
UNIVERSALITY
• The genetic code is universal.
• AUA is the codon for methionine
in mitochondria.The same codon
(AUA) codes for isoleucine in
cytoplasm.With some exceptions
noted the genetic code is
universal.
NON-
OVERLAPPING
• One base cannot
participate in the
formation of more
than one codon.
• This means that the
code is non-
overlapping.

7. DEGENERACY
• There are more than one
codon for one amino acid.
• This is called degeneracy
of genetic code.

8. Wobble Hypothesis
• Francis Crick proposed the wobble hypothesis in
1966 to explain the pattern of degeneracy.
• Though there are 61 codons coding for amino acids, we
do not need 61 types of tRNA.
• The 3rd nucleotide in the anticodon is often less
important than the first two (binds weakly / not specific).
• The third nucleotide is in the “wobble” position

9. • Uttam Kumar Patel
E-mail:-uttampatel494@gmail.com