Description : Regulation of haem synthesis occurs by (A) Covalent modification (B) Repression - derepression (C) Induction (D) Allosteric regulation
Last Answer : Answer : B
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
Last Answer : Answer : C
Description : Pyruvate dehydrogenase complex is regulated by (A) Covalent modification (B) Allosteric regulation (C) Both (A) and (B) (D) None of these
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
Last Answer : Answer : D
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
Last Answer : Answer : A
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 : Covalent modification of an enzyme usually involves phosphorylation / dephosphorylation of (A) Serine residue (B) Proline residue (C) Hydroxylysine residue (D) Hydroxyproline residue
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 : Which one of the following enzymes requires a coenzyme derived from the vitamin whose structure is shown below? (A) Enoyl CoA hydratase (B) Phosphofructokinase (C) Glucose-6-phosphatase (D) Glucose-6-phosphate dehydrogenase
Description : Post-transcriptional modification of hnRNA involves all of the following except (A) Addition of 7-methylguanosine triphosphate cap (B) Addition of polyadenylate tail (C) Insertion of nucleotides (D) Deletion of introns
Description : Microbial breakdown of phenoxy herbicides such as 2,4-D and MCPA is enhanced by addition of a). Nitrate b). Sulphate c). Phosphate d). Chlorate
Last Answer : c). Phosphate
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 : Conversion of pepsinogen to pepsin is (A) Intra molecular rearrangement (B) Breaking of hydrogen bonds (C) Covalent modification (D) Polymerisation
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 : Covalent modification of an enzyme generally requires a (A) Hormone (B) cAMP (C) Protein kinase (D) All of these
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 : A reduction reaction always involves the: w) loss of electrons x) gain of electrons y) addition of oxygen z) removal of oxygen
Last Answer : ANSWER: X -- GAIN OF ELECTRONS
Description : Which of the following coenzyme is required for porphyrin synthesis? (A) Coenzyme A (B) Pyridoxal phosphate (C) Both (A) and (B) (D) None of these
Description : Sulphur containing coenzyme is (A) NAD (B) FAD (C) Pyridoxal phosphate (D) Biotin
Description : Vitamin B2 is component of coenzyme: (A) Pyridoxal phosphate (B) TPP (C) NAD (D) FMN/FAD
Description : A coenzyme present in phosphorylase is (A) NAD (B) Pyridoxal phosphate (C) Thiamin pyrophosphate (D) Coenzyme A
Description : A coenzyme required in transamination reactions is (A) Coenzyme A (B) Coenzyme Q (C) Biotin (D) Pyridoxal phosphate
Description : Which of the following coenzyme takes part in oxidation-reduction reactions? (A) Pyridoxal phosphate (B) Lipoic acid (C) Thiamin diphosphate (D) None of these
Description : Pyridoxal phosphate is a coenzyme for (A) Glycogen synthetase (B) Phosphorylase (C) Both (A) and (B) (D) None of these
Description : Pyridoxal phosphate is required as a coenzyme in (A) Transamination (B) Transulphuration (C) Desulphydration (D) All of these
Description : Pyridoxal phosphate is a coenzyme for (A) Glutamate oxaloacetate transaminase (B) Glutamate pyruvate transaminase (C) Tyrosine transaminase (D) All of these
Description : NAD is required as a coenzyme for (A) Malate dehydrogenase (B) Succinate dehydrogenase (C) Glucose-6-phosphate dehydrogenase (D) HMG CoA reductae
Description : FAD is a coenzyme for (A) Succinate dehydrogenase (B) Glycerol-3-phosphate dehydrogenase (C) Sphingosine reductase (D) All of these
Description : The vitamin required as coenzyme for the action of transaminases is (A) Niacin (B) Pantothenic acid (C) Pyridoxal phosphate (D) Riboflavin
Description : A coenzyme required for the synthesis of glycine from serine is (A) ATP (B) Pyridoxal phosphate (C) Tetrahydrofolate (D) NAD
Description : Transketolase has the coenzyme: (A) NAD+ (B) FP (C) TPP (D) Pyridoxol phosphate
Last Answer : C
Description : The main physiological buffer in the blood is (A) Haemoglobin buffer (B) Acetate (C) Phosphate (D) Bicarbonate
Description : The conversion of pyruvate to acetyl CoA and CO2 (A) Is reversible (B) Involves the participation of lipoic acid (C) Depends on the coenzyme biotin (D) Occurs in the cytosol
Last Answer : B
Description : Hormones (A) Act as coenzyme (B) Act as enzyme (C) Influence synthesis of enzymes (D) Belong to B-complex group
Description : Coenzyme is (A) Often a vitamin (B) Always an inorganic compound (C) Always a protein (D) Often a metal ENZYMES 173
Description : In most metabolic pathways, all needed enzymes are arranged together in a multienzyme complex within a (A) Solution of ATP (B) Membrane (C) Quanternary protein (D) Coenzyme
Description : If a coenzyme is required in an enzyme reaction, the former usually has the function of (A) Acting as an acceptor for one of the cleavage products of the substrate (B) Enhancing the specificity ... C) Increasing the number of receptor sites of the apo enzyme (D) Activating the substrate ENZYMES 167
Description : The enzymes with which nicotinamide act as coenzyme are (A) Dehydrogenases (B) Transaminases (C) Decarboxylases (D) Carboxylases
Description : An important function of vitamin A is (A) To act as coenzyme for a few enzymes (B) To play an integral role in protein synthesis (C) To prevent hemorrhages (D) To maintain the integrity of epithelial tissue
Description : What is the balanced chemical equation for lead II acetate and sodium sulphate?
Last Answer : The chemical equation is:Pb(CH3COO)2 + Na2SO4 = 2 CH3COONa + PbSO4(s)Lead sulfate is a precipitate.
Description : ‘Plaster of paris’ chemically known as (1) Sodium Aluminate (2) Calcium sulphate (3) Spdium bicarbonate (4) Sodium acetate
Last Answer : (2) Calcium sulphate Explanation: Calcium sulphate is a calcium salt that is used for a variety of purposes. It exists in various forms and states of hydration.
Description : Study the following table and choose the correct option: Salt - Parent Acid - Parent Base - Nature of Salt (a) Soidum Chloride - HCI - NaOH - Basic (b) Sodium Carbonate - H2CO3 - NaOH - Neutral (c) Sodium Sulphate - H2SO4 - NaOH - Acidic (d) Sodium Acetate - CH3COOH - NaOH - Basic
Last Answer : Answer: (d) Sodium Acetate - CH3COOH - NaOH - Basic
Description : The ‘stone’ formed in human kidney consist mostly of-------? A. Calcium oxalate (Answer) B. Sodium acetate C. Magnesium sulphate D. Calcium
Last Answer : A. Calcium oxalate (Answer)
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 : Enzymes which catalyse binding of two substrates by covalent bonds are known as (A) Lyases (B) Hydrolases (C) Ligases (D) Oxidoreductases
Description : In biotin-containing enzymes, the biotin is bound to the enzyme by (A) An amide linkage to carboxyl group of glutamine (B) A covalent bond with CO2 (C) An amide linkage to an amino group of lysine (D) An amide linkage to α-carboxyl group of protein
Description : When acetate is the sole source of carbon for some microorganisms, the cycle which is used, is called A.pentose phosphate pathway B.glycolyic pathway C.glyoxylate pathway D.oxaloacetate pathway
Last Answer : C.glyoxylate pathway
Last Answer : (B) Phosphorylase
Description : An advantge of betamethasone acetate over betamethasone sodium phosphate is (a) Fewer allergic reactions (b) Prompter action (c) More sustained action (d) Greater solubility (e) There is no advantage
Last Answer : Ans: C
Description : Synthesis of polyunsaturated fatty acids involves the enzyme systems: (A) Acyl transferase and hydratase (B) Desaturase and elongase (C) Ketoacyl-CoA reductase and hydratase (D) Dihydroxyacetone phosphate