Genetic Cod E Flashcards
Genetic code =
Term , discovered by
During translation genetic information from ,what does not exist
A codon is a
The relationship b/w sequence of amino acid in polypeptide chain and nucleotide of dna or mRNA George Gamow ( physicist) , Nirenberg , Mathaei,Khurana
Polymer of nucleotide to synthesise a polymer of amino acid , complimentary base pair
Nucleotide sequences of mRNA which code particular amino acids
Nirenberg & Mathhae developed , synthesised ________ rna eg
Above enzyme () , translate in
Har Gobind Khurana syntheses
Genetic code nature
Cell free system ( invitro ) for protein synthesis , homo polymer egg poly U,C,A
Severo Ochoa enzyme ( polynucleotide phosphorylase ) , cell free medium
RNA molecule with defined combination of base ( Homo polymer, copolymer
Triplet
Same genetic code exception
Explain non overlapping of genetic code ( formula
Overlapping
Frameshift mutation
Point mutation
Mitochondrial codon and some protozoans
A n2 base is constituents of only one codon = no of codon = no of nucleotide / 3
No of codon = no of nucleotide - 2
Insertion / deletion of 1 or 2 bases changes the reading frame from the point of insertion/deletion
insertion/deletion of 3 or its multiple in one or multiple codon
Unambiguous and specific eg
Degeneracy /
Eg module
Other eg
Specific by single codon
UUU code for 1 amino acid = phenyl adenine
Redundancy = single amino acid coded by more than one codon
Phenyl adenine = UUU &UUC , glycine =GGG,GGC etc
S= serine,A = Argenine , leucine
Only 2 amino acid = UGG= tryptophan, AUG. methionine
AUG dual fn =
In prokaryotes
In pro also as start codon
Stop codon / = eg, sense codon no
Initiation codon, code for methionine
AUG codes for N - formyl methionine
GUG = normally valine but also as N - formyl methionine
Non sense codon eg UAA( ochre) ,UAG(amber),UGA ( opal , 61
Wobbling , normally occurs at , responsible ,proposed by
Old central dogma proposed by , includes
Now included ,enzyme , given by
In protein sequence of amino acid dictated by , represented by
Anticodon recognises more than one codon , 3 nucleotide of codon,fordegeneracy ,crick
Francis Crick , transcription and translation
Reverse transcription/ teminism , rna dependent dna polymerase Temin & Baltimore
DNA , mRNA
Translation in prokaryotes takes place in , in eu
Translation and transcription can be coupled in bacteria because
First step amino acids are activated in
Forms also known as
Cytoplasm , Cytoplasm , mitochondria, plastids , surface of RER
Post transcriptional processing ( splicing ) not required
Both takes place in same compartment
Presence in ATP
Amino acryl AMP enzyme complex / activated amino acid
Charging of tRNA /
Requirement for synthesis of polypeptide chain
Initiation , what helps in pro for attachment to ribosome
S.d sequence +nt in ,
Asd +nt in
Loading/aminoacylation of tRNA
mRNA , charged tRNA , 30s,50 s , GTP , mg2+
S.D sequence and asd sequence
mRNA before 4-12 N bases of initiation codon
16 srna complimentary to sd sequence
First charged tRNA attached by the help of
Larger subunit of ribosomes have ____ site
Attachment of larger subunit of ribosome 50s
of IF2. And GTP
3 , psite = peptidyl site
A site = aminoacyl site
E site = exit site
Mg2+
Peptide bond formation takes place b/w
Favoured energetically by
Translocation ,helps
There are no __ for stop codons
COOH of psite ,NH2 of a site
Catalyst (23srna )
Ribosome slides over mRNA strand in 5’ to 3 ‘ direction , translocase enzyme
tRNAs
Utrs present at
Required for
Polyribosome //=
Both 5’ ( before start codon ),3’ ( after stop codon
Efficient translation process
Polysome /ergosome = 1 mRNA + many ribosomes
Gene regulation in eukaryotic
In pro
Transcriptional /formation of primary transcription (hnrna
RNA processing / regulation of splicing
Transportation of mRNA from nucleoplasm to cytoplasm
Translation
Transcriptional level
Constitutive gene / , always ,no need for eg
Non constitutive gene //, are not always , is needed
Types
Inducible
Repressible
Gene regulation in pro given by , worked on , gave
House keeping gene, remains active ,on , gene regulation , genes for enzymes of glycolysis
Smart gene , luxury , on /off , regulation
Generally off the. On
Generally on then off
Francis Jacob , Jacques Monad , ecoli , operon model
Operon
Genes present
Examples of operon ,,,,,
Each operon has its own
In bacteria more than one gene is arranged together and regulates
Structural gene , regulator gene (I), operator gene (o). Promotor gene (p)
Lac ( lactose ), trp ( tryptophan ) , Ara ( Arabinose ) ,his ( histidine ) , val ( valine )
It’s specific operator and specific repressor
Lactose ( carbohydrate )
Fn promoter
Operator
Regulator gene () () stands for
Codes for ,
Disaccharide compose of glucose and galactose
Binding site for rna polymerase
Binding site for repressor protein
i gene does not refer to inducer rather for inhibitor
Repressor protein ,