Biochemistry Basics

Question A protein with a molecular weight of 100 kD is subjected to SDS PAGE electrophoresis. The SDS PAGE electrophoresis pattern shows two widely separated bands of 20kD and 30kD after the addition of Mercaptoethanol. The true statement regarding this will be- A. The protein has undergone complete lysis B. The protein is a monomer […]

Question DNA synthesis requires: A. DNA polymerase B. DNA ligase C. DNA topoisomerase D. All   Show Answer Correct Answer » D Explanation Origin of Replication- The DNA replication starts with the recognition of the site of origin of replication. This is done by a complex called autonomous replicating sequences. The unwinding of DNA– Topo-isomerases, Gyrases,

Question Which of the following are the false statements ? A. Multiple origins of replication are possible for bacteria B. Lagging strand stick by RNA primase C. DNA replication proceeds in one direction D. All of the above   Show Answer Correct Answer » D Explanation Ans.D. All of the above The helicase or DnaB

Question Amino acids secreted in cystinuria are all except: A. Ornithine B. Histidine C. Arginine D. Lysine   Show Answer Correct Answer » B Explanation Ans: B  Histidine – Cystinuria Biochemical Defect: An autosomal recessive disorder that results in the formation of a defective amino acid transporter in the renal tubule and intestinal epithelial cells.

Question The correct sequence of enzymes required for DNA formation is: A. DNA polymerase Protein unwinding enzyme –> DNA ligase –> DNA Isomerase –> Polymerase -1 B. Protein unwinding enzyme –> Polymerase 1 –> DNA ligase–> DNA Isomerase–> DNA C. RNA polymerase –> DNA polymerase III –> DNA polymerase I –> DNA ligase D. RNA

Question True about DNA supercoiling is all except: A. Underwinding results in negative superhelical density & supercoiling B. Superhelical density depends on the length of DNA C. Underwinding strain is normally accommodated by strand separation D. Both B and C.   Show Answer Correct Answer » D Explanation Supercoils are introduced when a closed circle

Question Cystinuria is associated with excretion of which Amino Acids in urine: A. Cysteine, lysine, Tyrosine, and alanine B. Cysteine, lysine, ornithine, and alanine C. Cysteine, ornithine, lysine and arginine D. Cysteine, Ornithine, Lysine, Arginine   Show Answer Correct Answer » D Explanation Cystinuria Biochemical Defect: An autosomal recessive disorder that results in the formation

Question Nucleosome consists of: A. Histone B. DNA C. RNA D. A and B Both   Show Answer Correct Answer » D Explanation Nucleosomes Nucleosomes are primary structural units of chromatin. It consists of DNA bound to protein histones, i.e. core of protein histones wrapped with DNA. Histones are basic proteins rich in lysine and

Question A 40 yr old woman presents with progressive palmoplantar pigmentation. X-ray spine shows calcification of intervertebral discs. Adding Benedict’s reagent to urine, gives greenish brown precipitate and blue-black supernatant fluid. What is the diagnosis? A. Phenylketonuria B. Alkapt onuria C. Tyrosinemia type-2 D. Argininosuccinic aciduria   Show Answer Correct Answer » B Explanation Ans.B.

Question True about telomerase or telomere is/are: A. They are present at the ends of eukaryotic chromosome B. Increased telomerase activity favors cancer C. DNA dependent RNA polymerase D. A and B   Show Answer Correct Answer » D Explanation Ans.D  The ends of each chromosome contain structures called telomeres. Telomeres consist of short TG-rich