a)Tryptophan acts as a co-repressor,it acts as an effector to convert inactive to active repressor,so tryptophan biosynthesis repressed.
b)cell lacking the trp repressor regulator gene,so,there is no repressor synthesized.If we add trptophan in this cell,synthesis of tryptophan occur constitutively
c)Trp repressor always binds to the operator region of trp operon,no tryptophan is synthesized even in the absence of tryptophan.
4. In each of the following scenarios, indicate if E.coli tryptophan biosynthesis proteins will be expressed...
QUESTION 8 The following situations (1-4) involve different types of gene regulation in prokaryotic cells as shown. OFF and ON reter to whether the gene is transcribed or not. Draw clearly-labelled regulatory proteins and effector molecules in each diagram to explain how the regulation works in each case. The first one has been done for you as an example a) (6 marks) Type of Regulation Regulatory protein effector molecule 1 DNA X negative inducible OFF ON 2 negative repressible DNA...
3. Consider a hypothetical strain of E. coli (strain 401) that contains two mutations that affect tryptophan biosynthesis. The first mutation is a single nucleotide substitution that converts the second tandem Trp codon in region 1 of the Trp leader sequence into a stop codon (see slides 2-7 of Lecture 24 on iLearn) trp structural genes trpE trpD trpC trpB trpA PO Trp Leader Met-Lys-Ala-lle-Phe-Val-Leu-Lys-Gly-Trp-Trp-Arg-Thr Ser- Stop Assume that strain 401 also contains a mutation in the gene for the...
2. Note whether the sentence is true or false on the line following each sentence. If a statement is false, cross out one incorrect word or phrase in the sentence and write the correct word on top of the incorrect word. a. When glucose levels are high, CAMP levels are high, leading to the binding of CAP. When lactose levels are high, the repressor will not be bound; this all leads to the activation of lacZ transcription in bacteria. b....
Yet, all the cells in your body contain the same
genes (and same alleles). The difference across cell types
is that genes get selectively expressed (turned on or off)
based on the proteins needed for cellular function given their
environment.
Select which statement explains the reason why hair does not
normally grow on your muscle cells.
a.
Muscle cells have the gene for keratin, but do not express
it
b.
Muscle cells do not have the gene for keratin and...
Page < 2 > of 2 D. The trp operon would be expressed at high levels, comparable to its expression in the absence of trp 6. Based upon what you have learned about the E. coli trp operon, what could you say about expression of its structural genes in cells with large amounts of environmental trp, but expressing a mutant trp repressor that is unable to bind trp? A. The trp operon would be completely repressed due to the abundance...
5. (12pts) You have discovered a novel cell-signaling pathway, in which cells stimulated with a hormone, Simpson, leads to a cell death response. The pathway involves 5 proteins with the following signaling: Simpson (signal) Homer --I Marge > Bart Lisa MaggieCell growth (response) A. Do you expect the Simpson stimulus to lead to increased or decreased levels of cell growth? Please provide your reasoning. B. You construct a series of cell lines with mutations in each one of these genes...
expressed at high levels, comparable to its expression in the absence of trp 6. Based upon what you have learned about the E. coli trp operon, what could you say about expression of its structural genes in cells with large amounts of environmental trp, but expressing a mutant trp repressor that is unable to bind trp? A. The trp operon would be completely repressed due to the abundance of trp B. The trp operon would be transcribed much less than...
alllll them please all
To MOST readily demonstrate transformation of bacteria in the laboratory one could extract DNA from: A) his cells and add the DNA to his cells, then grow the cells on plates with histidine B) hist cells and add the DNA to his cells, then grow the cells on plates without histidine C) lac" cells and add the DNA to lact cells, then grow the cells on plates without histidine D) amp cells and add the DNA...
For Questions 4-18, consider the mutations described in the left-hand column below. Identify whether the Lac operon will be ON or OFF in each of the environments listed across the top. The expression of the normal (wild type) operon is given. Note that "ON" and "OFF" refer to whether the operon is expressed at high levels (ON) or basal//low/no levels (OFF). (Hint: mutations render the indicated site inactive while leaving the remaining part of the operon or protein functional.) Note...
Microbiology study guide questions. Please Help!
s. which of the following statements about water activity is not true? a) many fungi can tolerate aw levels of 07-0.8 b) many microorganisms grow well at an aw of 0.98 e sear water has an aw of 0.98 e-xerephiles thrive in dry conditions DNA typically becomes disordered below an a of o.90 Which of the following descriptions about ribosome structure is not true? a) 80s is the size of the intact functional ribosome...