Genetic Cod E Flashcards by Samrudhi Menthe

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

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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

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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

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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

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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

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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

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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

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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

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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+

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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

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Utrs present at
Required for
Polyribosome //=

Both 5’ ( before start codon ),3’ ( after stop codon
Efficient translation process
Polysome /ergosome = 1 mRNA + many ribosomes

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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

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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

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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

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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 ,

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The repressor of operon is synthesised
Structural gene contains , are
Type 1 codes for , responsible for
Type 2 code , fn
Types 3 code , fn

All the time constitutively from i gene
Lac z, lac y , lac a ( polycistronic structural gene ) , linked
Beta galactosidase enzyme , hydrolysis of disaccharide , lactose into its monomeric units , galactose and glucose
Lac y Permease enzyme , increases permeability of cell to beta galactosides ( lactose
Lac a enzyme transacetylase , transfer acetyl group from acetyl coA to beta galactosides

Why lactose is inducer
In absence of glucose , lactose is +nt then
In presence of inducer (eg ) , the represser is
This allows rna polymerase

It is substrate for enzyme beta - galactosidase and it regulates switching on / off of operon
Lactose is transported into cell through action of permease
(Lactose or allolactose ) , inactivated by interaction with inducer
To bind with promoter and transcription proceeds

Special point of lac operon ,i gene , z,y,a , it is a _________ pathway
Lac operon is an _____ operon ( __-> __ ) Real inducer ,
Lac operon show ___ regulation
Eg

Constitutive gene , non constitutive gene , catabolic
Inducible operon ( off on ) , allolactose
Negative ( repressor ) , positive ( activators )
- ve = regulatory molecule binds with dna and stop transcription eg repressor protein
+ve = regulatory molecules bind with dna and start transcription eg CAP protein ( catabolic activator protein )

Mutation results in , changes , What leads to variation in dna
Understood by mutation studies , heritable , non heritable
Word given by , studied on
Types

Alteration of dna , genotype , phenotype , recombination ( crossing over ) ,
Relationship b/w genes and dna , mutation in germinal cell , somatic cell
Hugo de vries , oenothera lamarckina ( evening primrose
Chromosomal mutation , gene

Chromosomal mutation =
Types

1= sub type
Sub sub type

Change in number or structure of chromosomes
Heteroploidy / genomatic mutation = change in chromosome no
Chromosomal aberration = change in structure of chromosome
Euploidy = change in no of sets of chromosome i,e either loss or addition of sets of chro
Mono Ploidy (x) +nce of 1 set chro , diploidy (2x)
Polyploidy +nce of more than two sets of chro
Triticale = Triticum aestivum (wheat ) x secale cereal (rye

Genomatic mutation, anuepolidy
Type 1eg
2 eg
Cause of aneuploidy is n

Change in no of chro in a set ,loss or addition of chro in set of chro
Hypoaneuploidy (losss) = monosomy ( 2n-1), double monosomy ( 2n-1-1 ) , nullisomy (2n-2)
Hyper aneuploidy ( addition ) = trisomy (2n+1) , double trisomy (2n+1+1),tetrasomy ( 2n+2)
Chromosomal nondisjunction means chro fail to separate during meiosis

Chromosomal aberration =
Types
1
Subtype 1 = eg

Loss ( deletion ) or gain ( insertion / duplication ) of segment of dna
Deletion ,inversion , duplication ,translocation
Deletion=loss of part or segment of chrom which leads to loss of some genes
Terminal deletion loss from 1 or both ends
Eg cri- du -chat syndrome in short arm of 5 th chro
Intercalary deletion = loss b/w ends

Inversion = eg
Duplication
Chromosomal aberration are commonly observed in
Above are sub type of

1234 l 5678. 1234 l 5768
Occur twice on chro
Cancer cells
Chromosomes aberration
Type of chromosomal mutation

Translocation ( chro aberration =
Type 1 eg
2 /
Exxx

A part of chro is broken and may be joined with non homo chro
Simple translocation 123456 - ABCDEF. 1234- ABCDEF56
Reciprocal translocation / illegitimate ( illegal crossing over )
123456 - ABCDEF. 1234EF = ABCD56
Chronic myeloid leukaemia (cml ) = blood cancer reciprocal translocation b/w 22 and 9 chro

Gene mutation / Two types 1 st type Cause change in ,which leads to eg Change may not occur some time cause

Point mutation = mutation arise due to change in sing,e base pair of dna Substitution , frame shift mutation Substitution = replacement of one n2 base by another One codon in genetic code , change in one amino acid in structure of protein , sickle cell anemia For one amino acid more than one type of codons are present

Point , substitution type 1 2 Frame shift mutation/ = Type 1,2 Due to frame shift mutation , so Eg

Transition = purine to purine or pyrimidine to pyrimidine Transversion = purine to pyrimidine or pyrimidine to purine Gibberish mutation = addition of one or rarely more than one n2 bases Addition / insertion , Deletion Complete reading of genetic code is changed, fms >>> substitution harmful Thalassamia ( lethal genetic disorder

NCERT frameshift mutation Point Mutagens ,ex Mutation are and they unit = , consists,

Insertion or deletion of one or two bases 3 or multiple of 3 Cause mutation 1non ionising radiation = Uv rays ,2 gamma rays Recessive and they never eliminate from population = muton = smallest part od dna which undergoes mutation , 1 mutation

Mis semse mutation Non semse mutation Same sense mutation

Nucleotide change in genetic code cause the change of one amino acid Nucleotide change in 1 one codon causes termination producing non sense codon Change in one nucleotide in codon does not change amino acid

DNA fingerprinting///, father (year) Indian fathers DNA same , different ( %, human genome ) , difference are mainly at ^^^ ^^^ are separated from bulk genomic dna by Bulk dna form

DNA typing, DNA profiling , DnA test , Alec Jeffery (1984) Dr V.K .Kashyap , Dr Lai Ji Singh 99.9%,0.1% ( 3.3x10 “9 ) , repetitive dna / satellite CsCl ( cesium chloride ) density gradient centrifugation Major peak ,

Satellite code , makes portion of genome Show high degree of Also shows high degree of ,in , Reasonnnn Forms

Do not code for any protein , large Polymorphism ( variation) in a population Polymorphism in homologous chromosome of an individual , In homologous pair one chromosome come from father and other chromosomes come from mother Basis of dna fingerprinting

Show same degree of polymorphism 1 2 Polymorphism mutation occur in coding part of DNA -> -> -> Mutation occur in non coding part -> -> -> Polymorphism arise due to

DNA from every tissue ( blood cells , hair follicle , skin,bone,saliva,sperm ) 2 b/w monozygotic twins Most of mutation lethal ,die can not transfer in next generation , mutation reject Most of chance to survive , mutation transfer to next generation, mutation accepted Mutation

Polymorphism basis of ,,,, Type of satellite dna basis Sequence rich , no of pair repetition , also called 1 2,,,size

Genetic mapping of human genome, evolution , dna fingerprinting,speciation Base composition , length of segment, no of repetitive units 1 micro satellite, A-T rich , 1 to 6 Bp , SSR ( simple sequence repeat ) 2 mini satellite , G-C rich , 11 to 60 Bp,VNTR ( variable no of Tandem repeats Size of vntr = 0.1 to 20 kb

VNTR end +nst Repetition no of VNTR vary in , so , except _____ ______ variation has traditionally described as dna polymorphism Reason

Palindromic sequence Homologous chromosomes , DNA of all human being are slightly different, monozygotic twins Allelic sequence variation, if more than one variant (allele) at a locus occurs in human population with a frequency greater than 0.01

In simple term what is referred as polymorphism (ncert High probability seen in

If an inheritable mutation is obsereved in a population at high frequency Non coding part