Biology ยท Chemistry
Carbohydrates and Biomolecules
1,073 Questions
Carbohydrates and biomolecules questions test your understanding of sugars, monosaccharides, and metabolic substrates. The topic covers food transportation in plants and the biochemical properties of sweeteners. Practicing these questions builds a strong foundation for exam preparation.
Disaccharides and monosaccharidesArtificial sweetenersGlycogen storagePlant food transportGlycoprotein hormones
Carbohydrates and Biomolecules Questions
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Sucrose
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Glucose
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Galactose
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Lactose
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Maltose
A
Correct answer
Explanation
Sucrose is a molecule with nine stereocentres and many sites that are reactive or can be reactive.
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Tangeritin
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Luteolin
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Apigenin
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Glycoside
D
Correct answer
Explanation
A glycoside is a molecule in which one or more sugar molecules is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides.
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phosphogluco isomerase
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hexokinase
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aldolase
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enolase
A
Correct answer
Explanation
Phosphoglucoisomerase (also called phosphohexose isomerase) converts glucose-6-phosphate to fructose-6-phosphate in glycolysis. This is an isomerization reaction.
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L-glucose
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D-glucose
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D&L-glyceraldehyde
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None of these
C
Correct answer
Explanation
L- and D-amino acid configurations are based on the stereochemical reference compound D- and L-glyceraldehyde, not glucose. Glyceraldehyde is the standard chiral reference molecule in organic chemistry. L-glucose and D-glucose themselves are assigned based on glyceraldehyde configuration.
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Sucrose
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Glucose
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Fructose
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Maltose
C
Correct answer
Explanation
Fructose is the sweetest naturally occurring sugar, approximately 1.7 times sweeter than sucrose (table sugar) and much sweeter than glucose or maltose. This is why fructose is used as a sweetener in many processed foods. Sucrose (common sugar), glucose (blood sugar), and maltose (malt sugar) are all less sweet by comparison.
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Glucose
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Starch
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Cellulose
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Hemoglobin
D
Correct answer
Explanation
Hemoglobin is a protein not a carcbohydrate.
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Glucose
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Fructose
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Sucrose
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Cellulose
D
Correct answer
Explanation
Cellulose is a classic imbibant - it absorbs water and swells without dissolving because it's hydrophilic but insoluble. Glucose, fructose, and sucrose are all soluble sugars that dissolve in water rather than imbibe it and swell.
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Cellulose
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Chitin
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Lignin
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Pectin
B
Correct answer
Explanation
Fungal cell walls are primarily composed of chitin, a tough polysaccharide also found in insect exoskeletons. This distinguishes fungi from plants (cellulose cell walls) and helps identify fungal cells. Pectin and lignin are plant cell wall components, not fungal.
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1, 2 and 4
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1, 4 and 5
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2, 3 and 4
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2, 3 and 5
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3, 4 and 5
D
Correct answer
Explanation
Phenylalanine, threonine and tryptophan: Glucogenic as well as ketogenic amino acids.
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Polysaccharides
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Oligosaccharides
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Disaccharides
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Monosaccharides
C
Correct answer
Explanation
Disaccharides contain 3-10 glucose units. These sugars can be hydrolysed into molecules of monosaccharide by the action of enzymes. They may be considered as glycosides formed by the condensation of two molecules of covalently linked monosaccharide. The empirical formula of disaccharide is C12H22O11.
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Sucrose
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Maltose
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Lactose
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Cellulose
C
Correct answer
Explanation
It is commonly known as milk sugar and is abundantly found in milk. On hydrolysis one molecule of lactose yields one molecule of galactose and a molecule of glucose. It is a reducing sugar.
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formic acid
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formoterol
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fructose
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fumaric acid
C
Correct answer
Explanation
Fructose, or fruit sugar, is a simple monosaccharide found in many foods. It is one of the three important dietary monosaccharides along with glucose and galactose.
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a glycosidic bond
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sigma bonds
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a hydrogen bond
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pi bonds
A
Correct answer
Explanation
A glycosidic bond is formed between the hemiacetal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some organic compound such as an alcohol.It is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate.
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Hemicellulose
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Pectin
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Lignin
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Microfibrils
A
Correct answer
Explanation
A hemicellulose is a heteropolymer present in almost all plant cell walls. It has a random, amorphous structure with little strength. It is easily hydrolyzed by dilute acid or base as well as myriad hemicellulase enzymes.
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xylose
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mannose
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galactose
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rhamnose
A
Correct answer
Explanation
Xylose is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group. It is the precursor to hemicellulose,