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 : 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
Last Answer : Answer : C
Description : Lipids are insoluble in water because lipid molecules are (a) hydrophilic (b) hydrophobic (c) neutral (d) zwitter ions.
Last Answer : (b) hydrophobic
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 : The amino acid exist as Zwitter ions when they are in (A) solid state (B) acidic solution (C) alkaline solution (D) neutral solution
Last Answer : Answer : D
Description : Hydrophobic bonds are formed in protein be- tween which amino acids?
Last Answer : Valine, leucine and isoleucine residues.
Description : Name some hydrophobic amino acids.
Last Answer : Valine, leucine and isoleucine.
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
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
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 : Skeletal muscle breakdown produces predominantly liberation of which two amino acids? A. Lysine. B. Tyrosine. C. Alanine. D. Glutamine. E. Arginine.
Last Answer : Answer: CD DISCUSSION: Alanine is released from skeletal muscle and extracted by the liver, where it is converted to new glucose. Glutamine is also released from muscle and participates in ... these two amino acids account for approximately two thirds of the nitrogen released from skeletal muscle
Description : The neutral amino acids for absorption need (A) TPP (B) B6 – PO4 (C) NAD+ (D) NADP+
Last Answer : Answer : B
Description : The third active process for amino acids transport involves (A) Acidic amino acids (B) Basic amino acids (C) Neutral amino acids (D) Sulphur containing amino acids
Description : The amino acid with a nonpolar side chain is (A) Serine (B) Valine (C) Asparagine (D) Threonine
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 : The importance of phospholipids as constituent of cell membrane is because they possess (A) Fatty acids (B) Both polar and nonpolar groups (C) Glycerol (D) Phosphoric acid
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
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 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 : Phosphorus and nitrogen ions generally get depleted in soil because they usually occur as (a) neutral ions (b) negatively charged ions (c) positively charged ions (d) both positively and negatively charged but disproportionate mixture.
Last Answer : (b) negatively charged ions
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 : 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 : 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 : Which amino acid has a net positive charge at physiological pH?
Last Answer : Arginine and lysine.
Description : Respiratory acidosis is that in which the blood pH is low due to increased retention of carbon dioxide caused by the lowering of the respiratory frequency or by pulmonary diseases that impair ... caused by metabolic disturbances that increase the concentration of bases (alkalis) in the blood.
Last Answer : Where are the chemoreceptors that detect the acidity of the blood and trigger the respiratory compensation located?
Description : Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions
Last Answer : these give unionised acid or base on reaction with added acid or alkali
Description : If neutral atoms become positive ions they?
Last Answer : have lost electrons
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 : There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s ... transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose
Last Answer : Answer: c, d The selectivity of the plasma membrane, although impressive, cannot account for the nonequilibrium composition of living cells. A cell can be maintained in a nonequilibrium state only by ... to drive the transport of a second species such as protons, calcium, amino acids, or glucose
Description : Which one of the following statements is true regarding digestion and absorption of food in humans? (a) Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions ... amylase in our mouth. (d) Oxyntic cells in our stomach secrete the proenzyme pepsinogen.
Last Answer : (a) Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like Na
Description : Carrier ions like Na+ facilitate the absorption of substances like (a) amino acids and glucose (b) glucose and fatty acids (c) fatty acids and glycerol (d) fructose and some amino acids.
Last Answer : (a) amino acids and glucose
Description : Pick out the wrong statement. (A) Nitrogen is normally supplied in fertiliser either in Ammoniacal or the nitrate form, from which the soil takes it up in the form of ammonium ions ornitrate ... nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens
Last Answer : (D) Ammonium nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens
Description : How is the acidic , basic character of acids and bases varies with respect to neutral water . Show these variations on the PH scale.
Last Answer : Ans: The PH of neutral water is 7 ,As the PH of solution deceases from 7 the acid characteristic of the solution increase so the acids having values 1 and 2 are strong acids and when the ... 7 the basic characteristic of the solution increase so the acids having values 11and 12 are strong bases.
Description : An aqueous solution of glycine is neutral because of the formation of : (a) Carbanion (b) Zwitterion (c) Carbonium ions (d) Free radicals
Last Answer : Zwitterion
Description : In a neutral solution (A) H+ions are absent (B) OH ions are absent (C) Both H+ and OH ions are present in very small but equal concentration (D) None of these
Last Answer : (C) Both H+ and OH ions are present in very small but equal concentration
Description : Why do you think polar and nonpolar molecules do not mix?
Last Answer : Because nonpolar molecules do not have positive and negative ends
Description : Which of the following terms denotes the polar molecules or negative ions clustered about a central positive ion? w) ligands x) isomers y) complex ions z) dipoles
Last Answer : ANSWER: W -- LIGAND
Description : Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the ... contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent
Last Answer : Answer: a, b, d The plasma membrane defines the boundary of the cell and serves to contain and concentrate enzymes and other macromolecule constituents. The plasma membrane is ... and bear carbohydrate moieties primarily as oligosaccharide chains that contribute to the cell coat or glycocalyx
Description : 12. The hydrophobic ends of phospholipid molecules are: (a) Polar (b) Non-polar © Neutral (d) Bipolar
Last Answer : Answer: b Non-polar
Description : Which of the following terms means that a crystal has the ability to capture and hold water molecules? w) hydroponic x) hygroscopic y) hydrophobic z) hydropholectic
Last Answer : ANSWER: X -- HYGROSCOPIC
Last Answer : All the elements that have a conjugate of one (1) are called monovalent elements. For example: Potassium.
Description : The pulmonary ventilation frequency (number of inhalations per time unit) rises or lowers the carbon dioxide concentration in blood. If it is intense the gas is more eliminated to the exterior and if it ... carbon dioxide and also of more hydrogen ions spending and the pH of the solution is raised.
Last Answer : What are acidosis and alkalosis?
Description : The concentration of (H+) ions is 4 x 10-5in a solution. Then pH of the solution will be (Given log 4 = 0.6) (A) 4.4 (B) 5.6 (C) 8.4 (D) 2.4
Last Answer : (A) 4.4
Description : Several applications have been suggested to increase the effectiveness of prophylactic application of topical fluoride which include all EXCEPT: A. Increase Fluoride ions in solution increase concentration B. Increase ... D. Pre-treat enamel with 0.5% phosphoric acid E. Use NH4F instead of NaF
Last Answer : B. Increase PH of fluoride
Description : pH is defined as the negative logarithm of the hydrogen ion concentration. Comparing a pH 5 and a pH 8 solution, which of the following is true? w) There are 1,000 times more hydrogen ions in ... . z) Cannot tell the difference between these two solutions by pH, since the numbers are so close.
Last Answer : ANSWER: X -- THERE ARE 1,000 TIMES MORE HYDROGEN IONS IN THE PH 5 SOLUTION
Description : A complex of platinum, ammonia and chloride produces four ions per molecules in the solution. The structure consistent with the observation is :
Last Answer : A complex of platinum, ammonia and chloride produces four ions per molecules in the solution. The structure consistent ... [Pt(NH_(3))_(4)Cl_(2)]Cl`