Description : Chloramphenicol inhibits bacterial protein synthesis by: A. Binding to 30S ribosome and inhibiting attachment of aminoacyl tRNA B. Binding to 50S ribosome and preventing peptide bond formation C. Binding to ... chain D. Binding to both 30S and 50S ribosome and inducing misreading of mRNA code
Last Answer : B. Binding to 50S ribosome and preventing peptide bond formation
Description : Initiation of protein synthesis begins with binding of (A) 40S ribosomal unit on mRNA (B) 60S ribosomal unit (C) Charging of tRNA with specific amino acid (D) Attachment of aminoacyl tRNA on mRNA
Last Answer : Answer : A
Description : The mechanism of antibacterial action of tetracycline involves (a) Binding to a component of the 50S ribosomal subunit (b) Inhibition of translocase activity (c) Blockade of binding of ... (d) Selective inhibition of ribosomal peptidyl transferases (e) Inhibition of DNA-dependent RNA polymerase
Last Answer : Ans: C
Description : Erythromycin acts on ribosomes and inhibit (A) Formation of initiation complex (B) Binding of aminoacyl tRNA (C) Peptidyl transferase activity (D) Translocation
Last Answer : Answer : D
Description : eIF-1A and eIF-3 are required (A) For binding of amino acyl tRNA to 40 S ribosomal subunit (B) For binding of mRNA to 40 S ribosomal subunit (C) For binding of 60 S subunit to 40 S subunit (D) To prevent binding of 60 S subunit to 40 S subunit
Description : Streptomycin prevents synthesis of polypeptide by (A) Inhibiting initiation process (B) Releasing premature polypeptide (C) Inhibiting peptidyl transferase activity (D) Inhibiting translocation
Description : Which binding is inhibited by pactamycin? A- Aminoacyl-tRNA to the A-site of 30S subunit B- Initiator-tRNA to 30S/40S initiation complexes C- Peptidyl t-RNA to the 50S subunit D- Formation of peptide bond in P site
Last Answer : Initiator-tRNA to 30S/40S initiation complexes
Description : During translation initiation in prokaryotes, a GTP molecule is needed in (a) formation of formyl-met-tRNA (b) binding of 30S subunit of ribosome with mRNA (c) association of 30S mRNA with formyl-met- tRNA (d) association of 50S subunit of ribosome with initiation complex.
Last Answer : (c) association of 30S mRNA with formyl-met- tRNA
Description : .During translation initiation in prokaryotes, a GTP molecule is needed in (a) formation of formyl-met-tRNA (b) binding of 30S subunit of ribosome with mRNA (c) association of 30S mRNA with formyl-met- tRNA (d) association of 50S subunit of ribosome with initiation complex.
Description : Okazaki fragment is related to (A) DNA synthesis (B) Protein synthesis (C) mRNA formation (D) tRNA formation
Description : The function of a repressor protein in an operon system is to prevent synthesis by binding to (A) The ribosome (B) A specific region of the operon preventing transcription of structural genes (C) The RNA polymerase (D) A specific region of the mRNA preventing translation to protein
Last Answer : Answer : B
Description : Eukaryotic initiation factors 4A, 4B and 4F bind to (A) 40 S ribosomal subunit (B) 60 S ribosomal subunit (C) mRNA (D) Amino acyl tRNA
Last Answer : Answer : C
Description : The newly entering amino acyl tRNA into A site requires (A) EF-II (B) Ribosomal RNA (C) mRNA (D) EF-I
Description : mRNA is complementary to the nucleotide sequence of (A) Coding strand (B) Ribosomal RNA (C) tRNA (D) Template strand
Description : Thymine is present in (A) tRNA (B) Ribosomal RNA (C) Mammalian mRNA(D) Prokaryotic mRNA
Description : Which of the following step of translation does not consume a high energy phosphate bond? (a) Peptidyl transferase reaction (b) Aminoacyl tRNA binding to A-site (c) Translocation (d) Amino acid activation
Last Answer : (b) Aminoacyl tRNA binding to A-site
Last Answer : (a) Peptidyl transferase reaction
Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination
Description : Binding of formylmehtionyl tRNA to 30 S ribosomal subunit of prokaryotes is inhibited by (A) Streptomycin (B) Chloramphenicol (C) Erythromycin (D) Mitomycin
Description : The role of molecular chaperones is to A-facilitate binding of ribosomes to mRNA B-degrade newly synthesized polypeptides that contain inaccurate sequences C-.facilitate binding of RNA polymerase to DNA D-aid a newly synthesized polypeptide in folding to its proper shape
Last Answer : -aid a newly synthesized polypeptide in folding to its proper shape
Last Answer : aid a newly synthesized polypeptide in folding to its proper shape
Description : ATP is required for (A) Fusion of 40S and 60S of ribosome (B) Accommodation tRNA amino acid in a site of ribosome (C) Movement of ribosome along mRNA (D) formation of tRNA amino acid complex
Description : GTP is not required for (A) Capping L of mRNA (B) Fusion of 40S and 60S of ribosome (C) Accommodation of tRNA amino acid (D) Formation of tRNA amino acid complex
Description : Ciprofloxacin inhibits the synthesis of (A) DNA (B) mRNA (C) tRNA (D) rRNA
Description : Novobicin inhibits the synthesis of (A) DNA (B) mRNA (C) tRNA (D) rRNA
Description : Okazaki pieces are formed during the synthesis of (A) mRNA (B) tRNA (C) rRNA (D) DNA
Description : Genetic information of nuclear DNA is transmitted to the site of protein synthesis by (A) rRNA (B) mRNA (C) tRNA (D) Polysomes
Last Answer : D
Description : The primary mechanism underlying the resistance of gram-positive organisms to macrolide antibiotics is (a) Methylation of binding sites on the 50S ribosomal subunit (b) Formation of ... ) Formation of drug-inactivating acetyltranferases (e) Decreased drug permeability of the cytoplasmic membrane
Last Answer : Ans: A
Description : .The first phase of translation is (a) binding of mRNA to ribosome (b) recognition of DNA molecule (c) aminoacylation of tRNA (d) recognition of an anti-codon
Last Answer : (d) recognition of an anti-codon.
Description : The first phase of translation is (a) binding of mRNA to ribosome (b) recognition of DNA molecule (c) aminoacylation of tRNA (d) recognition of an anti-codon.
Last Answer : c) aminoacylation of tRNA
Description : Which of the following statement(s) is/are true concerning translation of the mRNA message to protein synthesis? a. An adaptor molecule, tRNA, recognizes specific nucleic acid bases and unites them ... and the free amino acid occurs in the free cytoplasm d. Complete protein synthesis takes hours
Last Answer : Answer: a, b The synthesis of protein involves conversion from a four-letter nucleotide language to one of 20 chemically distinct amino acids. This process is referred to as ... translation and be moving down the mRNA molecules simultaneously, thus increasing the rate of protein synthesis
Description : What happens at the ribosome in the production of a protein? a. mRNA brings the codon b. tRNA brings the anticodon c. the amino acids are linked by polypeptide bonds d. translation e. all the above
Last Answer : c. the amino acids are linked by polypeptide bonds
Description : The interaction between the mRNA and tRNA determined the position of amino acid in a polypeptide sequence. This is called the A- stagerivity B- Wobble hypothesis C- Promiscuity D- adaptor hypothesis
Last Answer : adaptor hypothesis
Description : Which one of the following is wrongly matched? (a) Transcription - Writing information from DNA to tRNA. (b) Translation - Using information in mRNA to make protein. (c) Repressor protein - Binds to operator to stop enzyme synthesis. (d) Operon - Structural genes, operator and promoter.
Last Answer : (c) Repressor protein - Binds to operator to stop enzyme synthesis.
Last Answer : (d) Operon - Structural genes, operator and promoter
Description : Which of the following act as the blueprint or template for the process of protein synthesis that takes place on ribosomes? A.rRNA B.DNA C.tRNA D.mRNA
Last Answer : mRNA
Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor
Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein
Description : Calcium is important in skeletal muscle contraction because it (a) binds to troponin to remove the masking of active sites on actin for myosin (b) activates the myosin ATPase by binding to it ... filament (d) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (a) binds to troponin to remove the masking of active sites on actin for myosin
Description : Calcium is important in skeletal muscle contraction because it :- (1) binds to troponin to remove the masking of active sites on actin for myosin. (2) activates the myosin ATPase by binding to ... filament. (4) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (1) binds to troponin to remove the masking of active sites on actin for myosin.
Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus
Description : Translocase is an enzyme required in the process of (A) DNA replication (B) RNA synthesis (C) Initiation of protein synthesis (D) Elongation of peptides
Description : In prokaryotes, chloramphenicol (A) Causes premature release of the polypeptide chain (B) Causes misreading of the mRNA (C) Depolymerises DNA (D) Inhibits peptidyl transferase activity
Description : Translation results in the formation of (A) mRNA (B) tRNA (C) rRNA (D) A protein molecule
Description : mRNA is complementary copy of (A) 5′-3′ strand of DNA+ (B) 3′-5′ strand of DNA (C) Antisense strand of DNA (D) tRNA
Description : Anticodon sequence are seen in (A) tRNA and transcribed DNA strand (B) tRNA and complementary DNA strand (C) mRNA (D) mRNA and complementary DNA strand
Description : The genetic code operates via (A) The protein moiety of DNA (B) The base sequences of DNA (C) The nucleotide sequence of mRNA (D) The base sequence of tRNA
Description : Codons are in (A) DNA (B) mRNA (C) tRNA (D) rRNA
Description : Blue print for genetic information residues in (A) mRNA (B) tRNA (C) rRNA (D) DNA
Description : From DNA the genetic message is transcribed into this compound: (A) Protein (B) mRNA (C) tRNA (D) rRNA
Description : Genetic information originates from (A) Cistron of DNA (B) Codons of mRNA (C) Anticodons of tRNA (D) Histones of nucleoproteins