This document discusses genome structure and function, including genomics, the central dogma of life, transcriptome, proteome, genetic code, and characteristics of the genetic code. Some key points: - Genomics is the study of genome structure and function, including functional genomics, structural genomics, and comparative genomics. - The central dogma of life involves replication of DNA, transcription to RNA, and translation to protein. The current concept involves replication of the genome, transcription to the transcriptome, and translation to the proteome. - The transcriptome is the set of RNA transcripts from active genes. The proteome is the set of proteins expressed in a cell. - The genetic

1. GENOME STRUCTURE AND FUNCTION
Suguna
III/VI Pharm.D
sub : pharmacology
Nova college of pharmacy
Vegavaram ,west Godavari .

2. GENOMICS :
 The study of structure and function of
genome is referred as genomics.
FUNCTIONAL
GENOMICS
STRUCTURAL
GENOMICS
COMPARATIVE
GENOMICS
Represent
gene
expression
 Relationship
of genes with
gene products .
Refers to
structural
motifs and
complete
protein
structures.
Study of
comparative
gene
function and
phylogeny

3. What is genome ?
GENOME = store house of genetic
information .
The total DNA (genetic information )
contained in an organism or cell is
regarded as the genome .
It includes the chromosomes in nucleus
and DNA in mitochondria ,chloroplasts .

4. Central dogma of life :
 Replication (DNA)
↓↓transcription
 RNA
↓↓↓Translation
 Protein
(Conventional concept pre
–bioinformatics area)
 Replication(GENOME )
↓↓↓Transcription
TRANSCRIPTOME
↓↓↓Translation
 PROTEOME
(current concept –
bioinformatics era )

5. Transcriptome :
 The RNA copies of the active protein coding
genes represent transcriptome.
 Transcriptome →→initial product of gene
expression →→protein synthesis .
PROTEOME:
The cell’s repertoire (repository /storehouse ) of
proteins with their nature & biological functions is
regarded as proteome .
Proteome →→entire range of proteins
&biological functions →→in a cell.

6.  Triple base sequence of messenger
RNA ,I m ;universal specific ,non –
overlapping ,degenerate ,in character
;faithfully work under the dictates of
DNA: to exercise my master’s orders
for protein synthesis .”

7. GENETIC CODE :
 The 3 nucleotide (triplet ) base sequences
in m-RNA that acts as code for amino
acids in protein constitute the genetic
code or simply codons .
 The genetic code may be regarded as a
nucleotide bases (A,G,C &U ).
 It determines the sequence of amino
acids in proteins.

8. GENETIC CODE :
 61 codons codes for 20 amino acids
present in protein .
 codons classification :
 initiating codons
 functional codons
 stop codons or termination codons
or non –sense codons .

9. GENECTIC CODE:
 The start codon marks the site at which
translation into protein sequence begins.
 Ex :AUG,GUG (sometimes )
 The stop codon marks the site at which
translation ends(or )stops signals for
protein synthesis.
 Ex:UAA (amber ),UAG (ochre
),UGA(opal).

10.  Codons are composed of the 4
nucleotide bases .
 Purine : adenine (A) and guanine (G)
 Pyrimdines : Cytosine (C) & Uracil
(U)
 4 bases * 3 codons = 64
combinations
 The nucleotide sequence of the
codon on m-RNA is starts from 5’-
end to 3’- end

11.  In RNA:
 UAG ("amber")
 UAA ("ochre")
 UGA ("opal"
 In DNA:
 TAG ("amber")
 TAA ("ochre")
 TGA ("opal" or
"umber")
In the standard genetic code, there
are three different stop codons:

13. FROM FIRST BASE 5’- END WE HAVE TO
START SEQUENCE TO SECOND BASE
(MIDDLE ONE) AND THIRD 3’-END
Example :

15. GENETIC CODE :
Characteristic features of genetic code :
The genetic code is universal ,specific
,non –overlapping and degenerate .
Features :
Universality
Unambiguous
Non-overlapping
Degenerate

16. GENETIC CODE :
 Universality:
 Because AUA is the codon for
methionine in mitochondria & AUA is the
codon is codes for isoleucine in
cytoplasm .
 Specificity:
 It is unambiguous or highly –specific.
 Particular codon always codes for the
same amino acid .

17. GENETIC CODE :
 Ex: UGG is the codon for tryptophan.
 Non-overlapping:
 Genetic code is read from a fixed point as
a continuous base consequence .
 Comma less
 No punctuations .
 Ex: UUUCUUUAGAGGis read as
UUU/CUU/UAG/AGG.

18. GENETIC CODE :
 Degenerate :
 Most of the amino acids have more than 1
codon .
 So codon is degenerate or redundant .
Ex: 61 codons code for 20 amino acids
 Glycine has 4 codons .

19. GENETIC CODE :
 The ultimate effect of mutations is on
the translation through the alteration
in codons .
 some of the mutations are harmful.
 In SCA single base
 Ex: CTC→CAC in DNA
 GAG →GUC in RNA

20. References :
 BIOCHEMISTRY THIRD EDITION BY
U.Satyanarayana and U.chakrapani.
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