Complete the table below using + to indicate if the enzyme is synthesized and -t
ID: 201222 • Letter: C
Question
Complete the table below using + to indicate if the enzyme is synthesized and -to indicate if the enzyme will not be synthesized. Genotype symbols:1 = lacl (the repressor gene); P = Plac (the promoter). O = lacO (the operator), Z lacZ (the B-galactosidase gene), and Y- lacY (the permease gene). The minus sign accompanying the symbol (e.g., I) indicates a mutant gene; the plus sign indicates wild-type/functional gene. Oc is the constituitive operator mutation (the same as O- and Id genes make mutant subunits of the repressor protein (as opposed to l which you can think of as not making a product) and Is codes for the super-repressor protein, which will not release from the operator Inducer Absent: Inducer Present: Genotype -galactosidase Permease. -galactosidase permease p.Explanation / Answer
Answer: Explanaton provided
a) When inducer (lactose is absent) it cannot kick off the repressor so transcription of both enzymes inhibited. when lactose is present it will kick off the repressor from operator and both enzymes will be synthesized
b) When inducer (lactose is absent) it cannot kick off the repressor so transcription of both enzymes inhibited. However if inducer is present , then it will kick off the repressor from operator and permease enzyme can be synthesized but not beta galactosidase because it is Z- (Affects the structure of enzyme rendering it nonfunctional).
c) When inducer (lactose is absent) it cannot kick off the repressor so transcription of both enzymes inhibited. However if inducer is present , then it will kick off the repressor from operator and beta galactosidease enzyme can be synthesized but not permease because it is Y- (Affects the structure of enzyme rendering it nonfunctional).
d) In the absence of repressor both the enzymes will be produced no matter if inducer is there or not.
e) this is a super repressor- lactose cannot kick it off, so transcription of z and y FAILS whether lactose is around or not. so both enzymes are not synthesized even if lactose is around or not around
f) The constitutive operator deflects repressor and repressor cannot bind and transcription OCCURS whether lactose is around to not. so both enzymes are produced if inducer is present or absent
g) The constitutive operator deflects any repressor (even a super repressor) and transcription OCCURS whether lactose is around to not. so both enzymes are produced if inducer is present or absent
h) The constitutive operator deflects any repressor (even a super repressor) and transcription OCCURS whether lactose is around to not. however permease will not be produced in both cases because Y- (non functional enzyme).
i) I-d codes for mutant repressor so it will not be able to bind operator when inducer is present and both enzymes will be produced. If inducer is absent both enzymes will not be produced.
j) In first chromosome inhibitor is not there but second chromosome has inhibitor produced. so it will go and bind to operator and both enzymes cannot be synthesized if no inducer is present. However inducer when present kicks off repressor and transcription of both enzymes will occur.
k) In first chromosome inhibitor is not there but second chromosome has inhibitor produced. so it will go and bind to operator of first chromosome and both enzymes cannot be synthesized if no inducer is present. However inducer when present kicks off repressor and transcription of only beta galactosidease will occur. permease will never be produced.
l) this is a super repressor- lactose cannot kick it off, so transcription of z and y FAILS whether lactose is around or not. so both enzymes are not synthesized even if lactose is around or not around
m) The constitutive operator deflects repressor and repressor cannot bind and transcription OCCURS whether lactose is around to not. the second chromosome has O+ so repressor goes and bind to operator and only in the prsence in lactose (inducer ) enzymes will be produced if a functional copy is there. SO inducer is absent then permease is only synthesized. but when inducer present only beta galactosidase is produced no permease
n) Inducer absent: only beta galactosidase will be positive permease negative because Oc can work. when inducer present both enzymes are positive
o) The constitutive operator deflects any repressor (even a super repressor) and transcription OCCURS whether lactose is around to not. so both enzymes are produced if inducer is present or absent
p) Because of I+ from one chromosome can go and bind to both operators so in absence of inducer, none of enzymes will be synthesized. However when inducer is present both enzymes will be produced as there is atleast onfunctional copy of each
q) in this case, the first chromosome is a bust because of a bad promoter. so only second chromosome makes functional enzyme. Inducer absent then none enzymes are made but when inducer prsent only permease is made since beta galactosidase is non functional.
r) in this case, the first chromosome is a bust because of a bad promoter. Second chrosome has constitutive operator so repressor cannot bind to it. So when inducer absent or present only permease is made since beta galactosidase is non functional
s) in this case, the first chromosome is a bust because of a bad promoter. both enzymes cannot be produced no matter inducer is present or absent becayse both enzymes have non functional gene.
t) in this case, the second chromosome is a bust because of a bad promoter. so inducer absent both enzymes not produced but when inducer present only beta galactosidase will be produced since permease is non functional for first chromosome
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