Prepare for NEET Biology Biomolecules with MCQs & PYQs on NEET.GUIDE. Get free practice, previous year questions, and expert explanations of carbohydrates, proteins, and more.
Chitin, a structural polysaccharide found in the exoskeleton of insects and crustaceans, is composed of which monomers linked by what type of glycosidic bond?
Glucose; ฮฑ-1,4-glycosidic bond
N-acetylglucosamine; ฮฒ-1,4-glycosidic bond
Fructose; ฮฒ-2,1-glycosidic bond
Galactose; ฮฑ-1,4-glycosidic bond
Which factor significantly contributes to the stability of the DNA double helix, in addition to hydrogen bonding between bases?
Repulsive forces between phosphate groups
Base stacking interactions
Free rotation around the phosphodiester bond
Electrostatic attraction between sugars
Chitin, a structural polysaccharide found in the exoskeleton of arthropods, differs significantly from cellulose in terms of its monomeric unit. This difference primarily stems from:
The presence of an N-acetyl group at C-2 of the monomer
The type of glycosidic linkage between monomers
The degree of polymerization (chain length)
The three-dimensional arrangement of the polymer chains
Inulin, a storage polysaccharide found in some plants, differs from starch in several key aspects. Which of the following statements accurately describes a major difference between inulin and starch?
Inulin is a branched polymer, while starch is strictly linear.
Inulin is primarily found in animals, while starch is found in plants.
Inulin forms a helical structure, while starch forms a sheet-like structure.
Inulin is composed of fructose units linked by ฮฒ(2โ1) glycosidic bonds, while starch primarily consists of glucose units linked by ฮฑ(1โ4) and ฮฑ(1โ6) bonds.
Glycogen, the primary storage polysaccharide in animals, exhibits a highly branched structure. Which of the following best explains the significance of this branching for its function?
Branching increases the structural rigidity of glycogen, enabling it to form strong fibers.
Branching decreases the osmotic pressure exerted by glycogen within cells.
Branching facilitates the transport of glycogen across cell membranes.
Branching allows for rapid hydrolysis by providing multiple sites for enzyme action, crucial for quick energy release.
Agar, a polysaccharide extracted from certain red algae, is widely used as a solidifying agent in microbiological media. Which of the following structural features contributes most to agar's gelling properties?
High degree of branching similar to glycogen.
Presence of ฮฒ(1โ4) glycosidic linkages exclusively.
The presence of sulfated galactose residues and the formation of double helices.
Its ability to form highly crystalline structures similar to cellulose.
The structural polysaccharide peptidoglycan, a key component of bacterial cell walls, possesses a unique feature that distinguishes it from other polysaccharides. This feature is:
The presence of ฮฑ(1โ6) glycosidic linkages.
The exclusive use of glucose as its monomeric unit.
The presence of short peptide chains cross-linking the polysaccharide chains.
Its ability to form triple helices.
Hyaluronic acid, a glycosaminoglycan found in connective tissues, exhibits unique viscoelastic properties. Which combination of structural features contributes most significantly to these properties?
Branched structure with ฮฑ(1โ6) linkages, and high sulfate content.
Repeating disaccharide units containing glucuronic acid and N-acetylglucosamine, along with extensive hydration.
Linear structure with ฮฒ(1โ4) linkages, and hydrophobic interactions.
Presence of fucose residues and formation of triple helices.
A novel protein was discovered containing a unique amino acid with a side chain composed of a selenol group (-SeH). Compared to a cysteine residue (-SH) in a similar protein, this selenol-containing amino acid would MOST likely exhibit which property?
Increased reactivity towards oxidizing agents
Decreased reactivity towards oxidizing agents
Identical reactivity towards oxidizing agents
Formation of stronger disulfide bonds
A protein undergoes denaturation in a high urea concentration. Which of the following interactions is LEAST likely to be disrupted during this process?
Hydrophobic interactions
Hydrogen bonds
Ionic interactions
Peptide bonds
