List of top Biochemistry Questions on Molecular Biology

Which of the following enzymes under appropriate conditions produce single-stranded nicks in DNA?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Protein synthesis is a central function in cellular physiology and is the primary target of many naturally occurring antibiotics and toxins. Tetracyclines are a class of broad-spectrum antibiotics used in the management and treatment of infectious disease by inhibiting translational machinery in bacteria. Reason (R): Tetracyclines inhibit protein synthesis in bacteria by blocking the A site on the ribosome, preventing the binding of aminoacyl tRNA. In the light of the above statements, choose the most appropriate answer from the options given below:

A patient develops skin cancer and worsening hyperpigmentation following sun exposure. Which DNA repair pathway is most likely impaired?

A frameshift mutation from nucleotide insertion at position 4 of a 900-base mRNA is observed. What is the likely outcome?

In Hurler syndrome, which glycosaminoglycans accumulate and cause organ enlargement?

How much of protein content makes an E. coli cell, in terms of the percentage of the total weight of the cell?

In 2014, scientists added a new synthetic base pair to DNA. What was it called?

A researcher engineers a lac operon on a plasmid inactivating all parts of the lac operator and the lac promoter, replacing them with the binding site for the LexA repressor and promoter regulated by LexA. The plasmid is introduced into E.coli cells that have a lac operon with an inactive lacZ gene. Under what conditions will these transformed cells produce β-galactosidase?

In E. coli, the enzyme that fills gaps in duplexes by adding nucleotides to the 3’ end is called:

All of the following are true regarding mitochondrial DNA, EXCEPT?

What does chaperones assist in?