You have created a fusion between the trp operon, which encodes the enzymes for trptophan biosynthesis, under the regulatory control of the lac operator. Under which of the following conditions […]
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CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Prokaryotic Stress Response: PerR, RecA, Heat Shock Proteins, and Chaperonins in Oxidative, Acidic, and Thermal Stress
31.Following statements were made about stress response in prokaryotes: A. PerR functions as a major peroxide sensor in many Gram- positive bacteria. B. Extreme acidic pH induces RecA-mediated DNA damage, […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
How Operator and Structural Gene Mutations Affect Tryptophan Synthesis in E. coli: The trpR+ trpO- trpE+ / trpR+ trpO+ trpE- Case
30. A heterozygote of E.coli was produced with the following combination of mutations: trpR+ trpO– trpE+ / trpR+ trpO+ trpE– Where R is the repressor, O is the operator and […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Understanding the Role of Bacterial Stress Proteins: DnaK, DnaJ, GroEL, GroES, and GrpE in ATP-Dependent Protein Folding
In a form of stress response, bacteria synthesize a group of proteins called stress proteins (or heat shock proteins) such as DnaK,DnaJ, GroEL, GroES, and GrpE. DnaK is an ATP […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
What Happens When the Trp Repressor Cannot Bind Tryptophan? Insights into trp Operon Regulation
29. A mutant Trp repressor (TrpRm) that cannot bind tryptophan is isolated. In this mutant A. Trp operon is constitutively expressed. B. Trp operon is super-repressed. C. Trp repressor does […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
The Role of Protein Modifications: Acetylation, Hydroxylation, and Glycosylation in Degradation, Folding, and Protein-Protein Interactions
In bacteria, N-formyl methionine is the first amino acid to be incorporated into a polypeptide chain. Accordingly, one would think that all bacterial proteins have a formyl group at theiramino […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
How Tryptophan Binding to the trp Repressor Leads to Repression in the trp Operon
In Trp operon, binding of tryptophan to trp repressor lead to (1) Repression (2) Induction (3) Anti termination (4) Attenuation Introduction The trp operon in Escherichia coli is a classic model […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Tryptophan as the Negative Regulator of the trp Operon in E. coli
Which of the following is negative regulator of trp operon (1) Lactose (2) Allolactose (3) C-AMP (4) Tryptophan The trp operon in Escherichia coli is a classic example of negative gene […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
The Role of Protein Modifications: Acetylation, Hydroxylation, and Glycosylation in Degradation, Folding, and Protein-Protein Interactions
The following statements were made regarding the role of protein modifications A. Attachment of acetyl groups to the amino termini of proteins makes it more resistant to degradation. B. Attachment […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
The Role of Excess Tryptophan as a Co-repressor in trp Operon Regulation
26. In trp operon regulation excess tryptophan act as (1) Inducer (2) Activator (3) Repressor (4) Co-repressor Introduction: The trp Operon and Its Regulatory Logic The trp operon in Escherichia […]
