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 : Answer : A
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 : 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
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) No net charge (D) All of these
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 : 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 : Which is the amino acid having maximum buff- ering capacity at physiological pH?
Last Answer : Histidine.
Description : Isoelectric pH of an amino acid is that pH at which it has a (A) Positive charge (B) Negative charge (C) No charge (D) None of these
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 : 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 : 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 : ATP is called a. A nucleoside b. Physiological currency c. An amino acid d. Polynucleotide
Last Answer : b. Physiological currency
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
Last Answer : Answer : B
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 : At a pH below the isoelectric point, an amino acid exists as (A) Cation (B) Anion (C) Zwitterion (D) Undissociated molecule
Description : At isoelectric pH, an amino acid exists as (A) Anion (B) Cation (C) Zwitterion (D) None of these
Description : At physiological pH the ammonia is protonated to form
Last Answer : At physiological pH the ammonia is protonated to form
Description : The following attribute of a drug tends to reduce its volume of distribution: A. High lipid solubility B. Low ionisation at physiological pH values C. High plasma protein binding D. High tissue binding
Last Answer : C. High plasma protein binding
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 : 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 : For a point charge to feel a net force in a homogeneous magnetic field, which one of the following statements is true? The charge must: w) move parallel to the magnetic lines of flux x) have a component of its motion perpendicular to the lines of flux y) be stationary z) be a positive charge
Last Answer : ANSWER: X -- HAVE A COMPONENT OF ITS MOTION PERPENDICULAR TO THE LINES OF FLUX
Description : Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the sphere is then, (A) negative and distributed uniformly over the surface of the sphere ... (C) negative and distributed non-uniformly over the entire surface of the sphere (D) zero
Last Answer : (D) zero
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 : The following technique makes use of the difference in net charges of proteins at a given pH: (A) Thin layer chromatography (B) Ion exchange chromatography (C) High performance liquid chromatography (D) Paper chromatography
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 of the following is correct for an amino acid solution when it is in the acidic form? (a) pH > pKa (b) pH < pKa (c) zwitterionic (d) pH = 7
Last Answer : pH < pKa
Description : Which of the following gives a positive Ninhydrin test? (A) Reducing sugar (B) Triglycerides (C) α-amino acids (D) Phospholipids
Description : All α-amino acids give positive (A) Million’s test (B) Biurete test (C) Xanthproteic test (D) Ninhydrine test
Description : Xanthoproteic test is positive in proteins containing (A) Sulphur amino acids (B) α-Amino acids (C) Aromatic amino acids (D) Aliphatic amino acids
Description : Will amino acids give a positive biuret test?
Last Answer : No. This needs a minimum of two peptide bonds.
Description : Hormones act only on specific organs or tissues. These are called (A) Active sites (B) Reaction centre (C) Target organ/Tissue(D) Physiological site HORMONE METABOLISM 231
Description : The main physiological buffer in the blood is (A) Haemoglobin buffer (B) Acetate (C) Phosphate (D) Bicarbonate
Description : Most of calcium is present in bone, but 2% present in soft tissue and the blood is called (A) Calcinated blood (B) Solidified blood (C) Physiological blood(D) Colloidal blood
Description : The only known physiological methylating agents in the animal organism are (A) Choline and betaine (B) Choline and δ-adenosyl methionine (C) Betaine and δ-adenyosyl methionine (D) Dimehtyl glycine and betaine
Description : Physiological glycosuria is met with in (A) Renal glycosuria (B) Alimentary glycosuria (C) Diabetes Mellitus (D) Alloxan diabetes
Last Answer : B
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 : 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 : The pH of body fluids is stabilized by buffer systems. The compound which will be the most effective buffer at physiologic pH is (A) Na2HPO4 pKa = 12.32 (B) Na2HPO4 pKa=7.21 (C) NH4OH pKa = 7.24 (D) Citric acid pKa = 3.09
Description : A 0.22 M solution of lactic acid (pKa 3.9) was found to contain 0.20 M in the dissociated form and 0.02 M undissociated form, the pH of the solution is (A) 2.9 (B) 3.3 (C) 4.9 (D) 5.4
Description : At the pH of blood 7.4, the ratio between the carbonic acid and bicarbonate fractions is (A) 1 : 10 (B) 1 : 20 (C) 1 : 30 (D) 1 : 40
Description : Calcium absorption is interfered by (A) Protein in diet (B) Phytic acid in cereals (C) Alkaline intestinal pH (D) Vitamin D
Description : All of the following statements about uric acid are true except (A) It can be formed from allantoin (B) Formation of uric acid stones in kidneys can be decreased by alkalinisation of urine (C) Uric acid begins to dissociate at pH above 5.8 (D) It is present in plasma mainly as monosodium urate
Description : All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate