Description : All the following statements about pepsin are correct except (A) It is smaller than pepsinogen (B) It is formed by the action of HCl on its precursor (C) Its optimum pH is 1.0–2.0 (D) It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
Last Answer : Answer : D
Description : The enzyme enterokinase helps in conversion of (a) protein into polypeptides (b) trypsinogen into trypsin (c) caseinogen into casein (d) pepsinogen into pepsin.
Last Answer : (b) trypsinogen into trypsin
Description : Pepsinogen is converted to active pepsin by (A) HCl (B) Bile salts (C) Ca++ (D) Enterokinase
Last Answer : Answer : A
Description : The theory of interionic attraction attributed to Debye and Hückel: w) was disproved by Arrhenius x) accounts quantitatively for the attraction between ions in dilute aqueous solutions y) does not account for kindered "ion-activity" z) accounts for intra-molecular polar bonds
Last Answer : ANSWER: X -- ACCOUNTS QUANTITATIVELY FOR THE ATTRACTION BETWEEN IONS IN DILUTE AQUEOUS SOLUTIONS
Description : What convert inactive pepsinogen into active pepsin?
Last Answer : Hydrochloric Acid (HCL) converts inactive pepsinogen into an active pepsin. HCL also kills harmful pathogens or particles in our food when it reaches the stomach through the gastrointestinal duct.
Description : What will happen if the secretion of parietal cells of gastric glands is blocked with an inhibitor? (a) In the absence of HCl secretion, inactive pepsinogen is not converted into the active ... c) Gastric juice will be deficient in chymosin. (d) Gastric juice will be deficient in pepsinogen.
Last Answer : (a) In the absence of HCl secretion, inactive pepsinogen is not converted into the active enzyme pepsin.
Description : Which of the following set is required for digestion of protein (a) Rennin, lipase, pepsinogen (b) Rennin, pepsin, trypsin (c) Pepsin, trypsin, erepsin (d) Trypsin, chymotrypsin, rennin
Last Answer : (c) Pepsin, trypsin, erepsin
Description : Zymogen cells of gastric gland secrete (a) Pepsinogen (b) Chymotrypsin (c) Pepsin (d) Trypsin
Last Answer : (a) Pepsinogen
Description : Which of the following converts inactive pepsinogen into active pepsin : (a) HCI (b) Mucous (c) Hormone (d) Enterokinase
Last Answer : (a) HCI
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 : Assertion : o-Hydrozybenaldehyde is less soluable in water than p-Hydroxybenzalbenzaldehye. Reason : Intra molecular hydrogen bonding in o-Hydrozbenza
Last Answer : Assertion : o-Hydrozybenaldehyde is less soluable in water than p-Hydroxybenzalbenzaldehye. Reason : Intra ... D. Assertion is false, Reason is true
Description : The number of intra-chain disulphide bonds in pro-insulin: (A) One (B) Two (C) Three (D) Four
Last Answer : Answer : C
Description : Regulation of haem synthesis occurs by (A) Covalent modification (B) Repression - derepression (C) Induction (D) Allosteric regulation
Last Answer : Answer : B
Description : Which one of the following regulatory actions involves a reversible covalent modification of the enzyme? (A) Phosphorylation of ser-OH on the enzyme (B) Allosteric modulation (C) Competitive inhibition (D) Non-competitive inhibition
Description : Which of the following regulatory reactions involves a reversible covalent modification of an enzyme? (A) Phosphorylation of serine OH on the enzyme (B) Allosteric modulation (C) Competitive inhibition (D) Non-competitive inhibition
Description : All the following statements about acetyl CoA carboxylase are true except: (A) It is activated by citrate (B) It is inhibited by palmitoyl CoA (C) It can undergo covalent modification (D) Its dephosphorylated form is inactive
Description : Glucose-6-phosphatase and PEP carboxy kinase are regulated by (A) Covalent modification (B) Allosteric regulation (C) Induction and repression (D) All of these
Description : Pyruvate dehydrogenase complex is regulated by (A) Covalent modification (B) Allosteric regulation (C) Both (A) and (B) (D) None of these
Description : Covalent modification of an enzyme usually involves phosphorylation / dephosphorylation of (A) Serine residue (B) Proline residue (C) Hydroxylysine residue (D) Hydroxyproline residue
Description : Covalent modification of an enzyme generally requires a (A) Hormone (B) cAMP (C) Protein kinase (D) All of these
Description : Regulation of some enzymes by covalent modification involves addition or removal of (A) Acetate (B) Sulphate (C) Phosphate (D) Coenzyme
Description : Activation or inactivation of certain key regulatory enzymes is accomplished by covalent modification of the amino acid: (A) Tyrosine (B) Phenylalanine (C) Lysine (D) Serine
Description : Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following mechanism? (A) Allosteric regulation (B) Covalent modification (C) Induction and repression (D) All of these
Description : Give some examples of covalent modification.
Last Answer : Glycogen synthase is inactive, in the phosphorylated state, whereas glycogen phosphorylase is active when phosphorylated.
Description : What is covalent modification?
Last Answer : It means, either addition of a group to the enzyme protein by a covalent bond; or removal of a group by cleaving a covalent bond.
Description : DNA nucleotides are attached by (a) Hydrogen bonds (b) Covalent bonds (c) VANDER Wall's force (d) Electrovalent bonds
Last Answer : Ans:(b)
Description : The inter particle forces between linear chains in nylon-66 are __________ bonds. (A) Hydrogen (B) Covalent (C) Ionic (D) None of these
Last Answer : (A) Hydrogen
Description : The two polypeptides of human insulin are linked together by (a) covalent bond (b) disulphide bridges (c) hydrogen bonds (d) phosphodiester bond.
Last Answer : (b) disulphide bridges
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 : An inert element has electron shells that a. Overlap The Shells Of Other Atoms. b. Are Completely Filled With Electrons. c. Yield Hydrogen Ions. d. Form Covalent Bonds.
Last Answer : b. Are Completely Filled With Electrons.
Description : Covalent network crystals have-------? A. higher melting point then molecular crystals (Answer) B. lower melting point then molecular crystals C. discrete molecules linked by Van der waals forces D. hydrogen bonding
Last Answer : A. higher melting point then molecular crystals (Answer)
Description : Which of the following is not a possible reaction of a carbocation? (a) addition of a nucleophile (b) rearrangement to a more stable carbocation (c) addition of a proton to form an alkane (d) loss of a β-hydrogen to form an alkene
Last Answer : addition of a proton to form an alkane
Description : What differences in molecular structure might cause water to form hydrogen bonds while hydrogen sulfide does not form such bonds?
Last Answer : What is the answer ?
Description : Why do alcohols have boiling points much higher than hydrocarbons of similar molecular weight? (a) Alcohols have greater van der Waals attraction forces. (b) Alcohol molecules have greater ... of volatilization. (d) Alcohols must overcome greater ionic forces in the process of volatilization.
Last Answer : Hydrogen bonds must be broken in the process of volatilization
Description : Enzymes which catalyse binding of two substrates by covalent bonds are known as (A) Lyases (B) Hydrolases (C) Ligases (D) Oxidoreductases
Description : In quaternary structure, subunits are linked by (A) Peptide bonds (B) Disulphide bonds (C) Covalent bonds (D) Non-covalent bonds
Description : Number of possible intra molecular aldol condensation product on heating with NaOH `H_(3)C-overset(O)overset(||)(C)-CH_(2)-CH_(2)-CH_(2)-overset(O)ove
Last Answer : Number of possible intra molecular aldol condensation product on heating with NaOH `H_(3)C-overset(O)overset(|| ... CH_(2)-overset(O)overset(||)(C)-H`
Description : Polymers are classified into four categories namely thermosetting, thermoplastic, elastomer and fibre depending upon their (A) Molecular sizes (B) Magnitude of intermolecular forces (C) Resistance to heat (D) Polymerisation mechanism
Last Answer : (B) Magnitude of intermolecular forces
Description : Molecular weight of a polymer is equal to the molecular weight of the repeat unit multiplied by the degree of polymerisation. What is the molecular weight of poly vinyl chloride (PVC), if its degree of polymerisation is 800? (A) 50000 (B) 51600 (C) 49200 (D) 50800
Last Answer : (A) 50000
Description : Polycaprolactam (Nylon - 6) is produced by the condensation polymerisation of caprolactam at 240-280°C in which the conversion of caprolactam is about __________ percent. (A) 50 (B) 75 (C) 90 (D) 99
Last Answer : (C) 90
Description : A batch reactor is suitable for (A) Achieving cent percent conversion of reactants into products (B) Large scale gaseous phase reactions (C) Liquid phase reactions (D) Obtaining uniform polymerisation products in highly exothermic reactions
Last Answer : (C) Liquid phase reactions
Description : An enzyme in saliva which hydrolyzes starch is (A) Pepsinogen (B) Chymotrysin (C) α-Amylase (D) Malate
Description : Whcih of the following is a proenzyme? (A) Carboxypeptidase (B) Aminopeptidase (C) Chymotrypsin (D) Pepsinogen ENZYMES 159
Description : Proenzymes: (A) Chymotrysinogen (B) Pepsinogen (C) Both (A) and (B) (D) None of these
Description : (A) Heterolytic fission involves the breaking of a covalent bond in such a way that both the electrons of the shared pair are carried away by one of t
Last Answer : (A) Heterolytic fission involves the breaking of a covalent bond in such a way that both the electrons of ... IF (A) is incorrect but (R) is correct.
Description : Conversion of β-carotene into retinal requires the presence of (A) β-Carotene dioxygenase (B) Bile salts (C) Molecular oxygen (D) All of these
Description : How many covalent bonds does P have?
Last Answer : Need answer
Description : If the difference in electronegativity values between two atoms is more than 2.0 non-polar covalent bonds generally form?
Last Answer : At this value an ionic bond is formed.
Description : If the difference in electronegativity values between two atoms is less than 0.4 nonpolar covalent bonds generally form?
Last Answer : True apex:)