The mutarotation of glucose is characterized by :
(a) a change from an aldehyde to ketone structure.
(b) a change of specific rotation from a (+) to a (–) value.
(c) the presence of an intramolecular bridge structure.
(d) the irreversible change from α-D to the β-D form.

1 Answer

Answer :

the presence of an intramolecular bridge structure.

Related questions

Description : Which of the following statements best describes the meaning of mutarotation ? (a) a rapid exchange between the α and β forms of diastereomeric sugars (b) a rapid exchange between the D ... between hydrogen and deuterated hydrogen (d) a slow change in optical rotation to reach an equilibrium value

Last Answer : a slow change in optical rotation to reach an equilibrium value

Description : Which of the following statements is false about α-D-glucose? (a) it has a pyranose ring. (b) it is a hemiacetal. (c) it shows mutarotation. (d) it is the purest form of table sugar.

Last Answer : it is the purest form of table sugar.

Description : An aqueous solution of glucose behaves as an aldehyde because __________. (a) it is hydrolyzed by water to the free aldehyde (b) it is a ketone, but is in equilibrium with the aldehyde form ... aldehyde (d) its cyclic hemiacetal, the predominant form, is in equilibrium with the free aldehyde form

Last Answer : its cyclic hemiacetal, the predominant form, is in equilibrium with the free aldehyde form

Description : The appearance of a silver mirror in Tollens' test indicates the presence of : (a) an aldehyde (b) a ketone (c) an alcohol (d) an alkene

Last Answer : an aldehyde

Description : α-D-glucose + 1120→ + 52.50 ← + 190 βD-glucose for glucose above represents (A) Optical isomerism (B) Mutarotation (C) Epimerisation (D) D and L isomerism

Last Answer : B

Description : An aldehyde can be oxidized to form: w) a ketone x) an acid y) an alcohol z) an ester 

Last Answer : ANSWER: X -- AN ACID

Description : Mutarotation refers to change in (A) pH (B) Optical rotation (C) Conductance (D) Chemical properties

Last Answer : B

Description : . Monosaccharides are classified according to : (a) the number of carbon atoms in the molecule. (b) whether they contain an aldehyde or a ketone group (c) their configurational relationship to glyceraldehyde. (d) all of the above

Last Answer : all of the above

Description : Which of the following is the correct ranking in decreasing order of relative Boiling Point of carbonyl containing compounds? (a) primary amide > carboxylic acid >> ester ~ acyl chloride ~ aldehyde ~ ketone ... chloride ~ amide (d) carboxylic acid > amide >> ester ~ acyl chloride ~ aldehyde ~ ketone

Last Answer : primary amide > carboxylic acid >> ester ~ acyl chloride ~ aldehyde ~ ketone

Description : Organic compound (A), C4H8O, does not react with sodium or PCl5. However, it reduces an alkaline solution of a copper (II) salt on heating. Compound (A) could be (a) an aldehyde (b) a primary alcohol (c) a ketone (d) a secondary alcohol

Last Answer : an aldehyde

Description : An organic compound (A), C3H8O, on oxidation gives (B), C3H6O. The compound (A) could be (a) an aldehyde (b) a ketone (c) an alcohol (d) an ester

Last Answer : an alcohol

Description : Oxidation of a secondary alcohol with K2Cr2O7/H+ produces (a) a carboxylic acid (b) a ketone (c) an aldehyde (d) an ester

Last Answer : a ketone

Description : Which of the following is correct? (a) When a Grignard reagent reacts with a ketone, the addition product is a primary alcohol. (b) When a Grignard reagent reacts with a ketone, the addition product ... with a aldehyde, the addition product is a tertiary alcohol. (d) None of the above are correct.

Last Answer : None of the above are correct.

Description : Ethylmagnesium iodide reacts with formaldehyde to give a product which on acid-hydrolysis forms : (a) an aldehyde (b) a primary alcohol (c) a ketone (d) a secondary alcohol

Last Answer : a primary alcohol

Description : Dry ice on reaction with GR gives_______ a) Ester b) Carboxylic acid c) Aldehyde d) Ketone

Last Answer : b) Carboxylic acid

Description : Cyclohexanone is an example of: w) an aldehyde x) a carboxylic acid y) an alkyne z) a ketone

Last Answer : ANSWER: Z -- A KETONE 

Description : α-D-Glucose is different from β-D-glucose (a) in the configuration at C-1 (b) because they are mirror images of each other (c) because they are enantiomers (d) because they are geometrical isomers

Last Answer : in the configuration at C-1

Description : When semicarbazide reacts with a ketone (or aldehyde) to form semicarbazone. Only one nitrogen atom of semicarbazide acts as a nucleophile and attack

Last Answer : When semicarbazide reacts with a ketone (or aldehyde) to form semicarbazone. Only one ... atoms of semicarbazide are relatively non nucleophilic ?

Description : Acid and alcohol react to form (a) Aldehyde and water (b) Ketone and water (c) Acid anhydride and water (d) Ester and water

Last Answer : Ans:(d)

Description : Carboxylic acid reacts with halogen in presence of red P to gives__________ a) α-halogen acids b) β-halogen acid c) Acid halide d) Dicarboxylic acid

Last Answer : a) α-halogen acids

Description : Which of the following is true about sucrose? (a) It hydrolyzes to fructose and glucose. (b) It is a reducing sugar. (c) It is a monosaccharide. (d) It undergoes mutarotation in water.

Last Answer : It hydrolyzes to fructose and glucose.

Description : Indicate the starting aldehyde or ketone from which each of the following compounds are formed by an aldol condensation reaction. (a)2-Ethyl-3-hydroxy

Last Answer : Indicate the starting aldehyde or ketone from which each of the following compounds are formed by an ... hexanal (b) 4-Hydroxy-4-methyl-2-pentanone

Description : Indicate the starting aldehyde or ketone from which each of the following compounds are formed by an aldol condensation reaction. (a)2-Ethyl-3-hydroxy

Last Answer : Indicate the starting aldehyde or ketone from which each of the following compounds are formed by an ... hexanal (b) 4-Hydroxy-4-methyl-2-pentanone

Description : Which disaccharide has no free aldehyde or ketone group?

Last Answer : Sucrose.

Description : When haemoglobin takes up oxygen there is a change in the structure due to the moving closer together of (A) β-chains (B) β-chains (C) γ-chains (D) α and γ chains

Last Answer : Answer : A

Description : Which of the following may characterize the “secondary structure” of proteins? (a) conformation of the protein backbone (b) α-Helix (c) parallel β-pleated sheet (d) all of the above

Last Answer : all of the above

Description : Von Gierke’s disease is characterized by the deficiency of (A) Glucose-6-phosphatase (B) α -1→ 4 Glucosidase (C) 1→ 6 Glucosidase (D) Liver phosphorylase

Last Answer : Answer : A

Description : Which of the following statements is false about an aldohexose? (a) It is a monosaccharide. (b) It contains a potential aldehyde group. (c) α-D-Glucopyranose is an aldohexose. (d) Fructose is an aldohexose

Last Answer : Fructose is an aldohexose

Description : Cellulose is made up of the molecules of (A) α-glucose (B) β-glucose (C) Both of the above (D) None of these

Last Answer : A

Description : In glucose the orientation of the —H and —OH groups around the carbon atom 5 adjacent to the terminal primary alcohol carbon determines (A) D or L series (B) Dextro or levorotatory (C) α and β anomers (D) Epimers

Last Answer : A

Description : α-D-glucose and β -D-glucose are (A) Stereoisomers (B) Epimers (C) Anomers (D) Keto-aldo pairs

Last Answer : C

Description : Cellulose, the most important constituent of plant cell wall is made up of (a) branched chain of glucose molecules linked by β-1, 4 glycosidic bond in straight chain and α-1, 6 glycosidic bond ... the site of branching (d) unbranched chain of glucose molecules linked by α-1, 4 glycosidic bond.

Last Answer : (b) unbranched chain of glucose molecules linked by β-1, 4 glycosidic bond

Description : Adrenaline raises blood glucose level by the following actions except: A. Inducing hepatic glycogenolysis B. Inhibiting insulin secretion from pancreatic β cells C. Augmenting glucagon secretion from pancreatic α cells D. Inhibiting peripheral glucose utilization

Last Answer : D. Inhibiting peripheral glucose utilization

Description : Adrenaline raises blood glucose level by the following actions except: A. Inducing hepatic glycogenolysis B. Inhibiting insulin secretion from pancreatic β cells C. Augmenting glucagon secretion from pancreatic α cells D. Inhibiting peripheral glucose utilization

Last Answer : D. Inhibiting peripheral glucose utilization

Description : Acyl-CoA dehydrogenase converts Acyl CoA to α-β unsaturated acyl-CoA in presence of the coenzyme: (A) NAD+ (B) NADP+ (C) ATP (D) FAD

Last Answer : Answer : D

Description : In proteins the α-helix and β-pleated sheet are examples of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure

Last Answer : Answer : B

Description : The primary structure of a protein refers to : (a) whether the protein is fibrous or globular (b) the amino acid sequence in the polypeptide chain (c) the orientation of the amino acid side chains in space (d) the presence or absence of an α-helix

Last Answer : the amino acid sequence in the polypeptide chain

Description : All the following statements correctly describe ketone bodies except (A) They may result from starvation (B) They are present at high levels in uncontrolled diabetes (C) They include—OH β-butyrate and acetone (D) They are utilized by the liver during long term starvation

Last Answer : Answer : D

Description : Which of the following products of triacylglycerol breakdown and subsequent β-Oxidation may undergo gluconeogenesis? (A) Acetyl CoA (B) Porpionyl CoA (C) All ketone bodies (D) Some amino acids

Last Answer : Answer : B

Description : The acetyl CoA formed on β-oxidation of all long chain fatty acids is metabolized under normal circumstances to (A) CO2 and water (B) Cholesterol (C) Fatty acids (D) Ketone bodies

Last Answer : Answer : A

Description : Insulin release from pancreatic β cells is augmented by the following except: A. Ketone bodies B. Glucagon C. Vagal stimulation D. Alfa adrenergic agonists

Last Answer : D. Alfa adrenergic agonist

Description : If ̳α ‘ and ̳β ‘ are the zeroes of a quadratic polynomial x 2 − 5x + b and α − β = 1, then the value of ̳b‘ is (a) – 5 (b) 6 (c) 5 (d) – 6

Last Answer : (b) 6

Description : If α , β are the zeroes of f(x) = px 2 – 2x + 3p and α + β = αβ then the value of p is: (a) 1/3 (b) -2/3 (c) 2/3 (d) -1/3

Last Answer : (c) 2/3

Description : Radiations which is not emitted during radioactivity is – (1) α rays (2) β rays (3) γ rays (4) Cathode rays

Last Answer : (4) Cathode rays Explanation: Radioactivity is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. It includes the emission of energetic alpha particles (α), beta particles (β), and gamma rays.

Description : Radioactive elements emit – (1) Radiowaves (2) Infrared waves (3) Ultraviolet waves (4) α, β and γ radiations

Last Answer : (4) α, β and γ radiations Explanation: The phenomenon of spontaneous emission of certain kinds of radiations by some elements is called radioactivity and the elements emitting such radiations are called ... the radioactive substances are separated in to three types, called a, b and g rays.

Description : When cathode rays strike a target of high atomic weight, they give rise to – 1) α -rays (2) β and γ rays (3) X-rays (4) positive rays

Last Answer : (3) X-rays Explanation: When cathode rays strike a solid target of high atomic weight and high melting point such as tungsten, molybdenum, etc, they give rise to a highly pen-etrating radiation called the X-rays (LIT Physics by Dr. P.K Aganval).

Description : Which of the following would give a positive Tollen’s test? (a) α-D-glucopyranose (b) methyl β-D-glucopyranoside (c) sucrose (d) methyl α-D-ribofuranoside

Last Answer : α-D-glucopyranose

Description : Which of the following is the main structural feature of proteins? (a) Peptide linkage (b) Ester linkage (c) Ether linkage (d) α,β-Linkage

Last Answer : Peptide linkage

Description : Claisen condensation gives__________ a) Hydroxyl compound b) β- keto ester c) Γ- diketone d) Α-diketone

Last Answer : b) β- keto ester

Description : Which of the following statements is false about glyceraldehyde? (a) Its IUPAC name is 1,2-dihydroxypropanal (b) It is isomeric with 1,3-dihydroxypropanone (c) It is optically active (d) It shows mutarotation

Last Answer : It shows mutarotation