Description : Isoelectric pH of an amino acid is that pH at which it has a (A) Positive charge (B) Negative charge (C) No net charge (D) All of these
Last Answer : Answer : C
Description : Isoelectric pH of an amino acid is that pH at which it has a (A) Positive charge (B) Negative charge (C) Nil net charge (D) None of these
Description : The isoelectric point of a protein is (a) the pH at which the protein molecule has no charges on its surface. (b) the pH at which a protein in solution has an equal number of positive and negative charges. (c) the electric charge under isothermal conditions. (b) None of these
Last Answer : the pH at which a protein in solution has an equal number of positive and negative charges
Description : At a pH below the isoelectric point, an amino acid exists as (A) Cation (B) Anion (C) Zwitterion (D) Undissociated molecule
Last Answer : Answer : A
Description : At isoelectric pH, an amino acid exists as (A) Anion (B) Cation (C) Zwitterion (D) None of these
Description : The true statement about solutions of amino acids at physiological pH is (A) All amino acids contain both positive and negative charges (B) All amino acids contain positively charged side chains ... amino acids contain only positive charge (D) All amino acids contain negatively charged side chains
Description : The true statement about solutions of amino acids at physiological pH is (A) All amino acids contain both positive and negative charges (B) All amino acids contain positively charged side chains ... amino acids contain only positive Charge (D) All amino acids contain negatively charged side chains
Last Answer : (A) All amino acids contain both positive and negative charges
Description : The pH at which the amino acid shows no tendency to migrate when placed in an electric field is known as its : (a) Isoelectric point (b) Dipole moment (c) Iodine number (d) Wavelength
Last Answer : Isoelectric point
Description : Which amino acid has a net positive charge at physiological pH?
Last Answer : Arginine and lysine.
Description : A hexa peptide with 5 aspartic acid would have a net charge at pH 7: (A) Neutral (B) Positive (C) Negative (D) Not predictable
Description : Since the pK values for aspartic acid are 2.0, 3.9 and 10.0, it follows that the isoelectric (pH) is (A) 3.0 (B) 3.9 (C) 5.9 (D) 6.0
Last Answer : (A) 3.0
Description : The amino acids in which the R groups have a net positive charge at pH 7.0 are (A) Lysine, Arginine, Histidine (B) Lysine, Aspargine (C) Histidine, Aspargine (D) Glutamine, Arginine
Description : Velocity maximum for an enzyme at half the substrate concentration gives (A) The molecular weight of the enzyme (B) Km value (C) Isoelectric pH (D) Pk value
Last Answer : Answer : B
Description : Isoelectric pH is that pH at which protein is electrically: (A) Neutral (B) Anionic (C) Cationic (D) None of these
Description : The pH at which an enzyme has maximum activity is known as (A) Isoelectric pH (B) Optimum pH (C) Low pH (D) High pH
Description : This technique takes the advantage of the fact that each protein has different pH at which it is electrically neutral i.e., its isoelectric pH: (A) Isoelectric focussing (B) Immunoel Ectro Phoresis (C) Chromatography (D) HPLC
Description : In the genetic disorder of cystinuria, the patient excretes large quantities of cystine in their urine and its low solubility causes crystalline cystine to precipitate as stones in kidneys. The remedy ... C) NaHCO3 prevents stone formation by hydrolysis of cystine to cysteine (D) None of these
Description : pH (isoelectric pH) of alanine is (A) 6.02 (B) 6.6 (C) 6.8 (D) 7.2
Last Answer : (A) 6.02
Description : Isoelectric point of amino acids is used for (A) Crystallisation (B) Precipitation (C) Solubility (D) Reactivity
Description : When the net charge on an amino acid is zero, the pH is maintained as? (A) 4.5 (B) 11.2 (C) 7.0 (D) 9.1
Description : At neutral pH, a mixture of amino acids in solution would be predominantly: (A) Dipolar ions (B) Nonpolar molecules (C) Positive and monovalent (D) Hydrophobic
Last Answer : (A) Dipolar ions
Description : A Zwitter ion is one which has in aqueous solution: (A) One positive charge and one negative charge (B) Two positive charges and one negative charge (C) Two negative charges and one positive charge (D) No electrical charges at all
Description : A compound gives a positive Tollens' test but negative Ninhydrin test. It is (a) a protein (b) an amino acid (c) a monosaccharide (d) pyridine
Last Answer : a monosaccharide
Description : The amino acid which has a pK near 4 and thus is negatively charged at pH 7 is (A) Alanine (B) Glutamic acid (C) Glutamine (D) Aspargine
Description : Which one of the following statements concerning glutamine is correct? (A) Contains three tetratable groups (B) Is classified as an acidic amino acid (C) Contains an amide group (D) Migrates to the cathode during electrophoresis at pH 7.0
Description : Which one of the amino acids could serve as the best buffer at pH 7? (A) Glutamic acid (B) Arginine (C) Valine (D) Histidine
Last Answer : Answer : D
Description : The greatest buffering capacity at physiologic pH would be provided by a protein rich in which of the following amino acids ? (A) Lysine (B) Histidine (C) Aspartic acid (D) Valine
Description : The pH of an amino acid depends (A) Optical rotation (B) Dissociation constant (C) Diffusion coefficient(D) Chain length
Description : Which is the amino acid having maximum buff- ering capacity at physiological pH?
Last Answer : Histidine.
Description : The Michaehis-Menten hypothesis: (A) Postulates the formation of an enzyme substrate complex (B) Enables us to calculate the isoelectric point of an enzyme (C) States that the ... independent of substrate concentration (D) States that the reaction rate is proportional to substrate concentration
Description : The solubility of most proteins is lowered at high salt concentrations is called as (A) Salting in process (B) Salting out process (C) Isoelectric focussing(D) None of these
Description : Which of the following techniques is used to separate proteins based upon differences in their mass? (A) Isoelectric focusing (B) Dialysis (C) SDS-gel Electrophoresis (D) Western blotting
Description : Amino acids excepting histidine are not good buffering agents in cell because (A) They exist as zwitter ions (B) Their pk and not in the physiological pH of a cell (C) Only Histidine has pk of its R group at 6.0 unlike the others which have at a different pH (D) None of these
Description : When amino acids are treated with neutral formaldehyde, the pH of the mixture (A) Is not altered (B) Increases (C) Decreases (D) First increases then decreases
Description : The only correct statement about chymotrypsin is (A) It is formed from trypsin (B) Carboxypeptidase converts trypsin into chymotrypsin (C) Its optimum pH is around 7 (D) It hydrolyses peptide bonds involving basic amino acids
Description : When there is an equal amount of positive and negative charges on an object what is the net charge of the object?
Last Answer : Feel Free to Answer
Description : Consider the following statements: 1. Even when a nerve cell is not conducting an impulse, it is actively transporting K+ and Na+ ions in and out respectively against their concentration gradients at the expense of energy 2. As a ... is/are untrue? (a) 1 only (b) 1, 2, 4 (c) 2, 4 (d) 4 only
Last Answer : Ans:(d)
Description : Area under current-time graph represents A. magnitude of charge B. dielectric C. amount of positive charge D. amount of negative charge
Last Answer : magnitude of charge
Description : If the plates of capacitor are oppositely charged then the total charge is equal to A. negative B. positive C. zero D. infinite
Last Answer : zero
Description : If we have a positive and a negative charge, then force between them is A. positive B. negative C. zero D. infinite
Last Answer : . negative
Description : During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge? (a) First positive, then negative and continue ... and again back to positive (d) First negative, then positive and again back to negative.
Last Answer : (d) First negative, then positive and again back to negative.
Description : Electron-withdrawing groups are meta directors because : (a) the carbonium ion intermediate has a negative charge on the meta position. (b) the more stable resonance hybrid occurs with meta ... the electrophile. (d) the carbonium ion intermediate has a positive charge on the meta position
Last Answer : the more stable resonance hybrid occurs with meta attachment of the electrophile.
Description : The compound methylamine, H3C–NH2, contains a C–N bond. In this bond, which of the following best describes the charge on the nitrogen atom? (a) slightly positive (b) uncharged (c) slightly negative (d) –1
Last Answer : slightly negative
Description : The cathode in an electrochemical cell always carries (A) Negative charge (B) Positive charge (C) Zero charge (D) Positive or negative charge depending upon the nature of the cell
Last Answer : (A) Negative charge
Description : An electron moves into the electrostatic field between a positive charge and a negative charge. Toward which charge will the electron move?
Last Answer : Toward the positive charge.
Description : A substance contains: (a) Only positive charge (b) Only negative charge (c) Both +ve and −ve charge (d) None of above
Last Answer : (c) Both +ve and −ve charge