REGULATION OF GENE EXPRESSION & DNA FINGERPRINTING Flashcards
regulation of gene in eukaryotes can be done at which levels
⬛ transcriptional level - formation of primary transcript
⬛ processing level - splicing
⬛ transfer of mRNA from nucleus to cytoplasm
⬛ translational level
what is beta galactosidase? use?
enzyme synthesised by E.coli
catalyse the hydrolysis of a disaccharide - lactose to galactose and glucose
used as a source of energy
give an example for gene regulation in adult organisms
development and differentiation of embryo
predominant site for gene regulation in prokaryotes
control rate of transcriptional initiation
operators
interactive proteins used for regulation (accessablity of promoter regions) in prokaryotes
where is the operator region present
adjacent to the promoter elements OR binding the repressor protein
regulatory proteins?
types?
regulate the activity of rna polymerase - affect its ability to recognise start sites
activators (act +vly)
repressors (act -vly)
lac operon was found by
Jacob And Monod
operon arrangements?
eg?
polycistronic structural gene is regulated by a common promoter and regulatory genes
lac trp ara his val
components of lac operon
regulatory gene: i gene OR inhibitor gene- codes for repressors
structural gene:
z gene - codes for Bgalactosidase
y gene - codes for permease (inc permeability of cell to Bgal)
a gene - codes transacetelylase
inducer in lac operon
lactose - substrate for Bgalactosidase
regulate on and off of the operon
OR allolactose
why a very low level of expression of lac operon has to be present in the cell all time
otherwise lactose cannot enter the cells
lac operon functioning
⚫i gene synthesis repressor all the time
⚫repressor protien binds to the operator region of the operon and prevents rna polymerase from transcribing the operon
⚫in the presence of inducer repressor is inactivated by interaction with the inducer
⚫this allows rna polymerase access the inducer and transcription proceeds
property behind lac operon
regulation of enzyme synthesis by its substrate
negative regulation
regulation of lac operon by repressor
how dna finger printing is the basis of paternity testing
as polymorphism is inheritable from parents to children
polymorphism?
reason?
variation at genetic level
arise due to mutations
basis of genetic mapping of human genome and dna fingerprinting
polymorphism
dna polymorphism
inheritable mutation due to germ cell mutation
who developed the dna fingerprinting technique
Alec Jeffreys
VNTR
variable number of tandem repeats
mini satellite dna probe used by jeffreys
sensitivity of dna fingerprinting technique is increased by the use of
polymerase chain reaction
uniqueness of autodiagram on dna fingerprinting technique shows exception in the case of
monozygotic twins (identical)
