Description : The double helical structure of DNA is held together by (a) sulfur-sulfur linkages (b) peptide bonding (c) hydrogen bonding (d) glycosidic bonds
Last Answer : hydrogen bonding
Description : The structural stability of the double helix of DNA is as cribbed largely to (A) Hydrogen bonding between adjacent purine bases (B) Hydrophobic bonding between staked purine and ... Hydrogen bonding between adjacent pyrimidine bases (E) Hydrogen bonding between purine and pyrimidine bases
Last Answer : Answer : D
Description : α-Helix is formed by (A) Hydrogen bonds (B) Hydrophobic bonds (C) Electrostatic bonds (D) Disulphide bonds
Last Answer : Answer : A
Description : The bond in proteins that is not broken under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
Description : Proteins react with biuret reagent which is suggestive of 2 or more (A) Hydrogen bonds (B) Peptide bonds (C) Disulphide bonds (D) Hydrophobic bonds
Last Answer : Answer : B
Description : The bond in proteins that is not hydrolysed under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
Last Answer : Answer : C
Description : In double helix of DNA, the two DNA strands are (a) coiled around a common axis (b) coiled around each other (c) coiled differently (d) coiled over protein sheath.
Last Answer : (a) coiled around a common axis
Description : The structure of DNA is a double helix formed by two strands of DNA sequence. This sequence consists of 4 different nucleotides- Adenine, Thymine, Cytosine and Guanine. How do the nucleotides on one strand interact with the nucleotides on the second strand to maintain the helical shape of DNA?
Last Answer : Complementary Base Pairing. Adenine complementary base pairs with Thymine and Guanine complementary base pairs with Cytosine.
Description : At the lowest energy level α-helix of polypeptide chain is stabilised (A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue (B) Disulphide bonds (C) Non polar bonds (D) Ester bonds
Description : Bonds that are formed between two cysteine residues is (A) Disulphide (B) Peptide (C) Electrostatic (D) Hydrophobic
Description : A protein reacts with biuret reagent which indicates 2 or more (A) Blood clotting (B) Peptide bond (C) Disulphide bonds (D) Hydrophobic bonds
Description : Why are the two strands of the double helix described as being complementary?
Last Answer : Complementarity is the key to understand the stability of the double helix of DNA in the Watson-Crick model (the most stable among other conformations). DNA complementarity property is determined by ... close to unity for deoxyribose nucleic acid." (In perfect agreement with the Chargaff's rules)
Description : The unwound strands of DNA are held apart by (A) Single strand binding protein (B) Double strand binding protein (C) Rep protein (D) DNAA protein
Description : Which of the following statements is not correct? (a) In man insulin is synthesised as a proinsulin. (b) The proinsulin has an extra peptide called C-peptide. (c) The functional insulin has A and B chains linked together by hydrogen bonds. (d) Genetically engineered insulin is produced in E.Coli.
Last Answer : (c) The functional insulin has A and B chains linked together by hydrogen bonds.
Description : Which bonds are the last to break when an enzyme is heated 1 disulphide 2 hydrogen 3 hydrophobic interactions 4 ionic?
Last Answer : ionic
Description : Which of the following is the least likely to be involved in stabilising the three-dimensional folding of most proteins (a) Hydrogen bonds (b) Electrostatic interaction (c) Hydrophobic interaction (d) Ester bonds
Last Answer : (d) Ester bonds
Description : α-helix is stabilized by (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds
Description : The a-helix of proteins is (A) A pleated structure (B) Made periodic by disulphide bridges (C) A non-periodic structure (D) Stabilised by hydrogen bonds between NH and CO groups of the main chain
Description : In sticky ends produced by restriction endonucleases (A) The 2 strands of DNA are joined to each other (B) The DNA strands stick to the restriction endonuclease (C) The ends of a double stranded fragment are overlapping (D) The ends of a double stranded fragment are non overlapping
Description : During transcription, do both strands of DNA get transcribed into a double stranded RNA molecule?
Last Answer : No. RNA is single stranded and is transcribed from only one of the DNA strands. DNA replication does make copies of both strands.
Description : The chemical forces that bind most coenzymes and substrates to enzymes such as LDH are (A) Hydrogen bonds (B) Peptide bonds (C) Coordinate bonds (D) Covalent bonds
Description : The hydrogen bonds between peptide linkages are interfered by (A) Guanidine (B) Uric acid (C) Salicylic acid (D) Oxalic acid
Description : Primary structure of a protein is formed by (A) Hydrogen bonds (B) Peptide bonds (C) Disulphide bonds (D) All of these
Description : Denaturation of proteins results in (A) Disruption of primary structure (B) Breakdown of peptide bonds (C) Destruction of hydrogen bonds (D) Irreversible changes in the molecule
Description : The hydrogen bonds between peptide linkages of a protein molecules are interfered by (A) Guanidine (B) Uric acid (C) Oxalic acid (D) Salicylic acid
Description : The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents? A. B. C ds DNA 3 5 5 3 ... - extension in the presence of heat stable DNA polymerase (d) A - annealing with two sets of primers
Last Answer : (c) C - extension in the presence of heat stable DNA polymerase
Description : What is the weak bond holding the nucleic acids together in DNA? a. ionic bonds b. covalent bonds bonds c. polar bond d. hydrogen bond
Last Answer : d. hydrogen bond
Description : The α-Helix is held in a coiled conformation partially because of : (a) Optical activity (b) Hydrogen bonding (c) Resonance (d) Delocalization
Last Answer : Hydrogen bonding
Description : The enzyme DNA ligase (A) Introduces superhelical twists (B) Connects the end of two DNA chains (C) Unwinds the double helix (D) Synthesises RNA primers
Description : If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6 × 109 bp, then the length of the DNA is approximately (a) 2.0 meters (b) 2.5 meters (c) 2.2 meters (d) 2.7 meters.
Last Answer : (b) 2.5 meters
Last Answer : (c) 2.2 meters
Last Answer : Double helix discovers DNA (Watson and Creek)
Last Answer : Watson And Creek DNA Double Helix Model Discovery Does.
Description : What are the components and structure of a DNA double helix molecule?
Last Answer : Feel Free to Answer
Description : The outside of the DNA double helix is made of alternating groups of deoxyribose sugars and _____.?
Last Answer : phosphates
Description : Melting temperature of DNA is the temperature at which (A) Solid DNA becomes liquid (B) Liquid DNA evaporates (C) DNA changes from double helix into supercoiled DNA (D) Native double helical DNA is denatured
Description : DNA topoisomerase I of E. coli catalyses (A) Relaxation of negatively supercoiled DNA (B) Relaxation of positively supercoiled DNA (C) Conversion of negatively supercoiled DNA into positively supercoiled DNA (D) Conversion of double helix into supercoiled DNA
Description : Left handed double helix is present in (A) Z-DNA (B) A-DNA (C) B-DNA (D) None of these
Description : The width (helical diameter) of the double helix in B-form DNA in nm is (A) 1 (B) 2 (C) 3 (D) 4
Description : Mitochondrial DNA is (A) Circular double stranded (B) Circular single stranded (C) Linear double helix (D) None of these
Last Answer : A
Description : The double helix model of DNA proposed by
Last Answer : Ans. Watson and Crick (1953)
Description : Double helix model of DNA was proposed by
Description : An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix ... nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand
Last Answer : Answer: c Transcription of a gene begins at an initiation site associated with a specific DNA sequence, termed a promoter region. After binding to DNA, the RNA polymerase opens up a short ... different proteins from the same gene. mRNA is exported from the nucleus only after processing is complete
Description : There are special proteins that help to open up DNA double helix in front of the replication fork. These proteins are (a) DNA ligase (b) DNA topoisomerase I (c) DNA gyrase (d) DNA polymerase I.
Last Answer : (c) DNA gyrase
Description : Radiotracer technique shows that DNA is in (a) multi-helix stage (b) single-helix stage (c) double-helix stage (d) none of these.
Last Answer : (c) double-helix stage
Description : The association of histone H1 with a nucleosome indicates that (a) DNA replication is occurring (b) the DNA is condensed into a chromatin fibre (c) the DNA double helix is exposed (d) transcription is occurring.
Last Answer : (b) the DNA is condensed into a chromatin fibre
Description : Which is wrong about nucleic acids? (a) DNA is single stranded in some viruses. (b) RNA is double stranded occasionally. (c) Length of one helix is 45 Å in B-DNA. (d) One turn of Z-DNA has 12 bases
Last Answer : (c) Length of one helix is 45 Å in B-DNA
Description : What is the genetic material in influenza virus? (a) Double helical DNA (b) RNA (c) Single helix DNA (d) None of these
Last Answer : (b) RNA
Description : The double helix is a structural arrangement associated with _____. a. A Polysaccharide. b. The DNA Molecule. c. Glucose Molecules In Starch. d. A Protein.
Last Answer : b. The DNA Molecule.