Biomolecules

Proteins are building blocks of the body but they do not provide energy for metabolism.

Most naturally occurring amino acids have L-configuration.

Cellulose is the chief constituent of the cell wall of plants. Wood contains while cotton contains cellulose.

Answer (c) a-4, b - 3, c-2, d- 1

Only sucrose is a non-reducing sugar as it does not reduce Tollen's reagent or Benedict's solution. (due to the absence of group).

When gluconic acid (a sugar alcohol) is oxidized with nitric acid, the oxidation occurs at the aldehyde group of the molecule, converting gluconic acid to saccharic acid (also known as glucaric acid). - Gluconic acid has a structure where an aldehyde group is oxidized to a carboxyl group upon reaction with nitric acid, leading to the formation of saccharic acid (C6H10O8). - Other options such as glucose or fructose are sugars, and oxidation with nitric acid would not lead to saccharic acid, but rather to other oxidation products. Thus, the correct answer is (E) saccharic acid.

- Cellulose: Cellulose is a polysaccharide found in plants, not in animals. It is the structural component of plant cell walls. - Starch: Starch is a polysaccharide found in plants, primarily used by plants to store energy. - Glycogen: This is the correct answer. Glycogen is the primary storage form of carbohydrates in animals, primarily stored in the liver and muscles. It can be broken down into glucose when needed by the body for energy. - Amylopectin: This is a component of starch, not a storage form of carbohydrates in animals. - Amylase: Amylase is an enzyme that breaks down carbohydrates, not a carbohydrate storage molecule. Thus, the correct answer is (C) glycogen.

Ionic radius tends to decrease as the charge on the ion increases, because the electrostatic attraction between the nucleus and the electrons becomes stronger, causing the electron cloud to contract. For transition metals in particular, the ionic radius decreases as the nuclear charge increases due to the increasing number of protons pulling the electrons closer to the nucleus. Comparing the ions: - Sc³⁺ (Scandium) has a +3 charge, and the electron configuration is [Ar], with only 18 electrons. The ion is highly contracted. - Ti³⁺ (Titanium) has a +3 charge with electron configuration [Ar], but it has a larger ionic radius than Sc³⁺ because of a greater number of protons pulling the electrons. - V³⁺ (Vanadium), Cr³⁺ (Chromium), and Mn³⁺ (Manganese) also have +3 charges but have slightly larger ionic radii as the nuclear charge increases compared to Sc³⁺. Thus, Sc³⁺ has the smallest ionic radius.

An expanded octet occurs when an atom has more than 8 electrons in its valence shell. This typically happens for atoms in the third period or higher, which have available d-orbitals that can accommodate more than 8 electrons. - NH (Ammonia): The nitrogen atom in NH₃ follows the octet rule with 8 electrons in its valence shell. - H SO (Sulfuric acid): The sulfur atom in H₂SO₄ does not have an expanded octet. It follows the octet rule with 8 electrons in its valence shell. - SF (Sulfur tetrafluoride): The sulfur atom in SF₄ has an expanded octet, with 10 electrons in its valence shell. This is possible because sulfur is in period 3 and can use d-orbitals to accommodate more electrons. - BeCl (Beryllium chloride): Beryllium typically does not expand its octet and follows the octet rule, having only 4 electrons in its valence shell. Thus, SF₄ is the correct answer as it has an expanded octet.