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

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
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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 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

Last Answer : Answer : B

It is the only amino acid having an ionizing ‘R’ group with a pK’ near 7 and is important in the active site of some enzymes: (A) Arginine (B) Cystein (C) Cystine (D) Histidine

Description : It is the only amino acid having an ionizing ‘R’ group with a pK’ near 7 and is important in the active site of some enzymes: (A) Arginine (B) Cystein (C) Cystine (D) Histidine

Last Answer : Answer : D

The amino acid exist as Zwitter ions when they are in (A) solid state (B) acidic solution (C) alkaline solution (D) neutral solution

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

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 : 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

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 (C) Some 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 : Answer : A

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 (C) Some 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

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 : 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

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 : 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

Buffering action of haemoglobin is mainly due to its (A) Glutamine residues (B) Arginine residues (C) Histidine residues (D) Lysine residues

Description : Buffering action of haemoglobin is mainly due to its (A) Glutamine residues (B) Arginine residues (C) Histidine residues (D) Lysine residues

Last Answer : Answer : C

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

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 : Answer : A

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

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

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

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 : Answer : A

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

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

Lipids are insoluble in water because lipid molecules are (a) hydrophilic (b) hydrophobic (c) neutral (d) zwitter ions.

Description : Lipids are insoluble in water because lipid molecules are (a) hydrophilic (b) hydrophobic (c) neutral (d) zwitter ions.

Last Answer : (b) hydrophobic

Which of the following amino acids produce a vasoconstrictor on decarboxylation? (A) Histidine (B) Tyrosine (C) Threonine (D) Arginine

Description : Which of the following amino acids produce a vasoconstrictor on decarboxylation? (A) Histidine (B) Tyrosine (C) Threonine (D) Arginine

Last Answer : Answer : B

All the following amino acids are nonessential except (A) Alanine (B) Histidine (C) Cysteine (D) Proline

Description : All the following amino acids are nonessential except (A) Alanine (B) Histidine (C) Cysteine (D) Proline

Last Answer : Answer : B

All α-amino acids have one asymmetric carbon atom except (A) Arginine (B) Glycine (C) Aspartic acid (D) Histidine

Description : All α-amino acids have one asymmetric carbon atom except (A) Arginine (B) Glycine (C) Aspartic acid (D) Histidine

Last Answer : Answer : B

α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine

Description : α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine

Last Answer : Answer : A

All amino acids have one asymmetric carbon atom, except (A) Arginine (B) Aspargine (C) Histidine (D) Glycine

Description : All amino acids have one asymmetric carbon atom, except (A) Arginine (B) Aspargine (C) Histidine (D) Glycine

Last Answer : Answer : D

Which is the amino acid having maximum buff- ering capacity at physiological pH?

Description : Which is the amino acid having maximum buff- ering capacity at physiological pH?

Last Answer : Histidine.

Which amino acid has a net positive charge at physiological pH?

Description : Which amino acid has a net positive charge at physiological pH?

Last Answer : Arginine and lysine.

Answer: b, c The body contains fuel reserves which it can mobilize and utilize during times of starvation or stress. By far the greatest energy component is fat, which is calorically dense since it provides about 9 calories/gram. Body protein comprises the next largest mass of utilizable energy, but amino acids yield only about 4 kcal/gram. Unlike fat reserves, body protein is not a storage form of energy but rather serves as a structural functional component of the body; loss of body protein, if severe, is associated with functional consequences. Glycogen stored in muscle and liver and free glucose have a trivial caloric value of less than 1000 kcal for a 70 kg male

Description : Answer: b, c The body contains fuel reserves which it can mobilize and utilize during times of starvation or stress. By far the greatest energy component is fat, which is calorically dense since it ... liver and free glucose have a trivial caloric value of less than 1000 kcal for a 70 kg male

Last Answer : Which of the following statement(s) is/are true concerning the indications and administration of nutritional support to cancer patients? a. Preoperative nutritional support should be provided to all ... total parenteral nutrition solutions maintain integrity of the small bowel e. None of the above

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

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

The amino acid which contains an indole group is (A) Histidine (B) Arginine (C) Cystine (D) Tryptophan

Description : The amino acid which contains an indole group is (A) Histidine (B) Arginine (C) Cystine (D) Tryptophan

Last Answer : Answer : D

The amino acid which contains an indole group is (A) Histidine (B) Arginine (C) Glycine (D) Tryptophan

Description : The amino acid which contains an indole group is (A) Histidine (B) Arginine (C) Glycine (D) Tryptophan

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The amino acid which contains a guanidine group is (A) Histidine (B) Arginine (C) Citrulline (D) Ornithine

Description : The amino acid which contains a guanidine group is (A) Histidine (B) Arginine (C) Citrulline (D) Ornithine

Last Answer : Answer : B

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 : 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

Last Answer : Answer : C

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

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

Wax is a (A) Mixture of glycerides (B) Mixture of esters of polyhydric alcohols excepting glycerine (C) Liquid at room temperature (D) Mixture of glycerides of fatty acids

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Last Answer : (B) Mixture of esters of polyhydric alcohols excepting glycerine

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 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

Last Answer : Answer : C

The active site of an enzyme is formed by (A) R group of amino acids (B) NH2 group of amino acids (C) CO group of amino acids (D) Sulphur bonds which are exposed

Description : The active site of an enzyme is formed by (A) R group of amino acids (B) NH2 group of amino acids (C) CO group of amino acids (D) Sulphur bonds which are exposed

Last Answer : Answer : A

The active site of an enzyme is formed by a few of the enzymes: (A) R groups of the amino acids (B) Amino groups of the amino acids (C) Carboxyl group of the amino acids (D) Exposed sulfur bonds

Description : The active site of an enzyme is formed by a few of the enzymes: (A) R groups of the amino acids (B) Amino groups of the amino acids (C) Carboxyl group of the amino acids (D) Exposed sulfur bonds

Last Answer : Answer : C

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) is/are true concerning energy converting transport? a. The site of energy conversion and transport in the plasma membrane involves the phospholipid component b. The Na+-K++-ATPase derives energy from hydrolysis of extracellular ATP c. In some systems, energy inherent in the transmembrane ion gradient can be used to drive transport of a second species d. Examples of species transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose

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

The pH scale relates the measure of _______ of a chemical substance. a. ionization b. denaturation c. acidity d. buffering

Description : The pH scale relates the measure of _______ of a chemical substance. a. ionization b. denaturation c. acidity d. buffering

Last Answer : c. acidity

Patient presents with rapidly progressive root caries on many teeth. Which of the following laboratory results would be a possible indicator of this? A. Stimulated salivary secretion rate of 1.5ml/min B. S. mutans concentration of 105 organism/ml C. A plaque sample containing 5% S. mutans D. A lactobacilli concentration of 105 organism/ml E. Salivary buffering PH 5.5 > 100000 CFU/ml high caries incidence

Description : Patient presents with rapidly progressive root caries on many teeth. Which of the following laboratory results would be a possible indicator of this? A. Stimulated salivary secretion rate of 1.5ml/min B. ... of 105 organism/ml E. Salivary buffering PH 5.5 > 100000 CFU/ml high caries incidence

Last Answer : E. Salivary buffering PH 5.5

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 : 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

An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline

Description : An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline

Last Answer : Answer : A

An amino acid required for porphyrin synthesis is (A) Proline (B) Glycine (C) Serine (D) Histidine

Description : An amino acid required for porphyrin synthesis is (A) Proline (B) Glycine (C) Serine (D) Histidine

Last Answer : Answer : A

Which of the following amino acid has been shown as one of the active site of phosphoglucomutase? (A) Lysine (B) Tyrosine (C) Serine (D) Histidine

Description : Which of the following amino acid has been shown as one of the active site of phosphoglucomutase? (A) Lysine (B) Tyrosine (C) Serine (D) Histidine

Last Answer : Answer : C

The amino acid which synthesizes many hormornes: (A) Valine (B) Phenylalanine (C) Alanine (D) Histidine

Description : The amino acid which synthesizes many hormornes: (A) Valine (B) Phenylalanine (C) Alanine (D) Histidine

Last Answer : Answer : B

Neutral amino acid is (A) Leucine (B) Lysine (C) Aspartic acid (D) Histidine

Description : Neutral amino acid is (A) Leucine (B) Lysine (C) Aspartic acid (D) Histidine

Last Answer : Answer : A

Which of the amino acid produces a vasodilator on decarboxylation? (A) Glutamin acid (B) Histidine (C) Ornithine (D) Cysteine

Description : Which of the amino acid produces a vasodilator on decarboxylation? (A) Glutamin acid (B) Histidine (C) Ornithine (D) Cysteine

Last Answer : Answer : B

The lone pair of electrons at one of the ring nitrogens in the given amino acid makes a potential ligand, which is important in binding the iron atoms in hemoglobin: (A) Tryptophan (B) Threonine (C) Histidine (D) Serine

Description : The lone pair of electrons at one of the ring nitrogens in the given amino acid makes a potential ligand, which is important in binding the iron atoms in hemoglobin: (A) Tryptophan (B) Threonine (C) Histidine (D) Serine

Last Answer : Answer : C

An amino acid not involved in urea cycle is (A) Arginine (B) Histidine (C) Ornithine (D) Citrulline

Description : An amino acid not involved in urea cycle is (A) Arginine (B) Histidine (C) Ornithine (D) Citrulline

Last Answer : Answer : B

The amino acid which synthesizes many hormones: (A) Valine (B) Phenyl alanine (C) Alanine (D) Histidine

Description : The amino acid which synthesizes many hormones: (A) Valine (B) Phenyl alanine (C) Alanine (D) Histidine

Last Answer : Answer : B

The basic amino acid: (A) Glycine (B) Leucine (C) Histidine (D) Proline

Description : The basic amino acid: (A) Glycine (B) Leucine (C) Histidine (D) Proline

Last Answer : Answer : C

The neutral amino acid is (A) Lysine (B) Proline (C) Leucine (D) Histidine

Description : The neutral amino acid is (A) Lysine (B) Proline (C) Leucine (D) Histidine

Last Answer : Answer : C

This amino acid cannot have optical isomers: (A) Alanine (B) Histidine (C) Threonine (D) Glycine

Description : This amino acid cannot have optical isomers: (A) Alanine (B) Histidine (C) Threonine (D) Glycine

Last Answer : Answer : D

Seratonin is derived in the body from the following amino acid: (A) Phenylalanine (B) Histidine (C) Tryptophan (D) Serine

Description : Seratonin is derived in the body from the following amino acid: (A) Phenylalanine (B) Histidine (C) Tryptophan (D) Serine

Last Answer : Answer : C

An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan

Description : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan

Last Answer : Answer : C