Carbohydrates are essential biomolecules comprising polyhydroxy aldehydes or ketones that serve as energy sources, structural components and key pharmaceutical excipients. This concise, pharmacy-focused overview addresses carbohydrate chemistry, natural sources (plant polysaccharides, animal glycogen, microbial), preparation methods (extraction, enzymatic and acid hydrolysis, fermentation), evaluation techniques (qualitative tests, TLC/HPLC, spectroscopy, moisture and purity assays), preservation and storage (water activity, temperature control, preservatives), therapeutic uses (parenteral dextrose, oral rehydration) and commercial utility (sweeteners, excipients, stabilizers). It includes preservation techniques, analytical approaches and practical formulation examples relevant to B.Pharm students. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the basic chemical definition of carbohydrates?
- Polyhydroxy aldehydes or ketones and their derivatives
- Long chain polypeptides composed of amino acids
- Lipids composed of fatty acids and glycerol
- Inorganic salts used in buffering
Correct Answer: Polyhydroxy aldehydes or ketones and their derivatives
Q2. Which of the following lists contains only common monosaccharides?
- Glucose, fructose and galactose
- Sucrose, lactose and maltose
- Starch, cellulose and glycogen
- Lactose, sucrose and starch
Correct Answer: Glucose, fructose and galactose
Q3. Which qualitative test is most general for detecting the presence of carbohydrates?
- Benedict’s test
- Molisch’s test
- Seliwanoff’s test
- Biuret test
Correct Answer: Molisch’s test
Q4. A glycosidic bond is formed between which atoms of two monosaccharides?
- Anomeric carbon of one and hydroxyl oxygen of another
- Carbonyl carbon and nitrogen of another
- Two carboxyl groups forming an ester
- Two amino groups forming an amide
Correct Answer: Anomeric carbon of one and hydroxyl oxygen of another
Q5. Alpha and beta anomers differ in configuration at which position?
- Penultimate carbon
- Anomeric carbon
- Terminal methyl group
Correct Answer: Anomeric carbon
Q6. Which common disaccharide is non-reducing?
- Sucrose
- Lactose
- Maltose
- Cellobiose
Correct Answer: Sucrose
Q7. Starch is composed primarily of which two polymers?
- Amylose and amylopectin
- Cellulose and chitin
- Glycogen and cellulose
- Inulin and pectin
Correct Answer: Amylose and amylopectin
Q8. Which linkage characterizes cellulose?
- Alpha-1,4 glycosidic bonds with branching
- Beta-1,4 glycosidic bonds forming linear chains
- Alpha-1,6 glycosidic bonds only
- Peptide bonds between monosaccharides
Correct Answer: Beta-1,4 glycosidic bonds forming linear chains
Q9. Why can humans digest starch but not cellulose?
- Humans lack enzymes to hydrolyze alpha-1,4 bonds
- Humans lack enzymes to hydrolyze beta-1,4 bonds in cellulose
- Cellulose is soluble and passes unchanged
- Starch is a protein and therefore digestible
Correct Answer: Humans lack enzymes to hydrolyze beta-1,4 bonds in cellulose
Q10. Modified starch in pharmaceuticals is primarily used as:
- Active pharmaceutical ingredient for infections
- Pharmaceutical excipient: binder, disintegrant and stabilizer
- Preservative to prevent microbial growth
- A volatile solvent for extraction
Correct Answer: Pharmaceutical excipient: binder, disintegrant and stabilizer
Q11. The Maillard reaction involves which functional groups and leads to what effect?
- Carboxyl groups and lipids causing rancidity
- Reducing sugars and amino groups causing browning and potential potency loss
- Hydroxyl groups and water causing hydrolysis
- Sulfhydryl groups and oxygen causing oxidation
Correct Answer: Reducing sugars and amino groups causing browning and potential potency loss
Q12. Intravenous dextrose solutions are primarily used clinically to provide:
- Electrolyte replacement only
- Parenteral calories and rapid energy source
- Antibiotic activity against gram-positive bacteria
- Lipid emulsification for fat-soluble drugs
Correct Answer: Parenteral calories and rapid energy source
Q13. High-sugar syrups preserve themselves chiefly because they:
- Have low pH that kills microbes
- Have low water activity that inhibits microbial growth
- Contain natural antibiotics
- Are stored at high temperatures
Correct Answer: Have low water activity that inhibits microbial growth
Q14. Which analytical method is the most accurate for determining trace water content in carbohydrate samples?
- Loss on drying
- Karl Fischer titration
- UV spectroscopy
- TLC
Correct Answer: Karl Fischer titration
Q15. Measurement of specific rotation in a carbohydrate sample helps determine:
- Thermal stability only
- Optical purity and configuration of stereocenters
- Elemental composition
- Particle size distribution
Correct Answer: Optical purity and configuration of stereocenters
Q16. Which chromatographic technique is commonly used for qualitative separation of mono- and disaccharides in routine labs?
- Gas chromatography (GC)
- Thin layer chromatography (TLC)
- Size exclusion chromatography for proteins
- Ion-exchange only for amino acids
Correct Answer: Thin layer chromatography (TLC)
Q17. Which HPLC detector is most suitable for detecting common carbohydrates that lack strong UV chromophores?
- UV-Vis detector at 280 nm
- Refractive index detector (RID)
- Fluorescence detector without derivatization
- Electrochemical detector optimized for peptides
Correct Answer: Refractive index detector (RID)
Q18. Which enzyme is primarily responsible for hydrolyzing starch to maltose and dextrins?
- Cellulase
- Amylase
- Invertase
- Sucrose phosphorylase
Correct Answer: Amylase
Q19. To inhibit fermentation and microbial growth in sugar syrups, which preservative is commonly used?
- Sodium chloride
- Sodium benzoate
- Calcium carbonate
- Magnesium stearate
Correct Answer: Sodium benzoate
Q20. High-fructose corn syrup production converts glucose to fructose using which enzyme?
- Invertase
- Glucose isomerase
- Amylase
- Sucrase
Correct Answer: Glucose isomerase
Q21. Which of the following is a reducing disaccharide?
- Sucrose
- Lactose
- Starch
- Cellulose
Correct Answer: Lactose
Q22. The primary carbohydrate storage polymer in animals is:
- Cellulose
- Starch
- Glycogen
- Inulin
Correct Answer: Glycogen
Q23. The best general storage recommendation to minimize degradative reactions in carbohydrate-containing formulations is:
- Storage in cool, dry conditions (low humidity and temperature)
- Storage in direct sunlight at room temperature
- Storage at high humidity to prevent drying
- Frequent freeze-thaw cycles to maintain structure
Correct Answer: Storage in cool, dry conditions (low humidity and temperature)
Q24. Which colorimetric assay is widely used to determine total carbohydrate content in a sample?
- Benedict’s test
- Phenol–sulfuric acid method
- Biuret assay
- Lowry protein assay
Correct Answer: Phenol–sulfuric acid method
Q25. Which monosaccharide is considered the sweetest naturally occurring common sugar?
- Sucrose
- Glucose
- Fructose
- Lactose
Correct Answer: Fructose
Q26. To promote formation of large, uniform sugar crystals during preparation, which technique is commonly applied?
- Rapid cooling without agitation
- Seeding of a supersaturated solution
- Continuous sonication
- Adding strong acid to induce precipitation
Correct Answer: Seeding of a supersaturated solution
Q27. The antimicrobial effect of concentrated sugar solutions (e.g., jams, syrups) is primarily due to:
- Low pH inhibiting all microbes
- High osmotic pressure causing cellular dehydration
- Presence of natural antibiotics in sugar
- High dissolved oxygen content
Correct Answer: High osmotic pressure causing cellular dehydration
Q28. Which qualitative test is used to distinguish ketoses from aldoses?
- Molisch’s test
- Seliwanoff’s test
- Benedict’s test
- Barfoed’s test
Correct Answer: Seliwanoff’s test
Q29. Which common monosaccharide is a ketose?
- Glucose
- Galactose
- Fructose
- Mannose
Correct Answer: Fructose
Q30. Which carbohydrate is most commonly used as a tablet diluent/filler in solid dosage forms?
- Cellulose (microcrystalline)
- Lactose
- Starch only as sweetener
- Fructose as a binder
Correct Answer: Lactose
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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