Which of the following statement about selenocysteine,the 21st amino acid present in several enzymes is true? (1) Selenium is enzymatically transferred to cysteineresidue only after the full functional protein getssynthesized. […]
Blog
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Cdc45: The Key Protein Required for Initiation and Continued Progression of Eukaryotic DNA Replication Fork
Which one of the following proteins is essential for both the initiation of DNA replication as well as the continued advance of the replication fork? (1) ORC (2) Geminin (3) […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Understanding the Three-Step Mechanism of E. coli DNA Ligase in DNA Repair and Replication
E. coli DNA ligase catalyses formation of a phosphodiester bond between the adjoining 3′ hydroxyl, and the 5′ phosphoryl ends in DNA duplexes. The energetic need for this reaction is […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
How Organisms Without Asparaginyl- and Glutaminyl-tRNA Synthetases Incorporate Asparagine and Glutamine
Many organisms encode only 18 aminoacyl-tRNAsynthetases (aaRS). These organisms lack aars that use Asn or Gln (as one of the substrates) for direct aminoacylation of the tRNAAsn and TrnaGln, respectively. Which […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Telomerase: The Key Enzyme Preventing Chromosome Shortening in Eukaryotic Cells
In eukaryotes shortening of chromosomes from ends is prevented bv (1) DNA polymerase (2) RNA polymerase (3) Telomerase (4) Transposase Introduction Eukaryotic chromosomes are linear structures with ends known […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Priming and RNA Primer Removal in Eukaryotic DNA Replication: DNA Polymerase α and FEN1 Functions Explained
54 In eukaryotic replication, priming of DNA synthesis and removal of RNA catalyzed by (1) DNAPol α and PCNA, respectively (2) DNA Pol α and FEN 1, respectively (3) DNA […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
How E. coli Incorporates Selenocysteine into Proteins: Role of Ser-tRNA^Sec Charging and SelB
Presence of selenocysteine in proteins in E. coli is a consequence of: (1) post-translational modification of cysteine present in special structural regions of the proteins by SelBand SelC. (2) post-translational […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
How Flap Endonuclease Inhibition Affects Gap Trimming During Non-Homologous End Joining in DNA Repair
In a human cell line, a large fraction of double-strand DNA breaks are repaired by non-homologous end joining (NHEJ). An inhibitor of FLAP endonuclease will affect (1) recruitment of DNA—dependent […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Role of DNA Polymerase I in Filling Gaps After RNA Primer Removal During Prokaryotic Lagging Strand Replication
In prokaryotes during replication, the lagging strand is synthesized in a series of short fragments known as Okazaki fragments, consequently requiring many primers. The RNA primers of Okazaki fragments are […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
How Selenocysteine Is Incorporated into Proteins: Charging of tRNA^Sec and UGA Codon Recoding
Amino acid selenocysteine (Sec) is incorporated into polypeptide chain during translation by: (1) charging of Sec into tRNAserfollowed byincorporation through serine codon (2) charging of serene into tRNAserfollowed by modification […]
