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Biology · BIOMOLECULES
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Biology · BIOMOLECULES
Given below are two statements: Statement I: The ash remaining after completely burning a living tissue sample contains inorganic compounds such as sulphate and phosphate in addition to inorganic ions. Statement II: Elemental analysis gives the elemental composition of living tissues, whereas compound analysis gives an idea of organic and inorganic constituents. In the light of the above statements, choose the most appropriate answer from the options given below:
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Which of the following carbohydrates is a polymer of fructose?
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Consider the following statements about protein structure: (A) In a polypeptide chain, the first amino acid is designated as the C-terminal amino acid. (B) In proteins, only right-handed helices are observed in the secondary structure. (C) Collagen is the most abundant protein in the animal world. (D) RuBisCO is the most abundant protein in the entire biosphere. (E) All proteins are homopolymers composed of repeating units of a single amino acid. Choose the correct answer from the options given below:
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During an enzyme-catalysed reaction, the substrate (S) binds to the active site to form an intermediate complex (ES), passing through an 'altered structural state' known as the transition state. Which of the following is true regarding this transition state structure?
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Identify the option that correctly classifies the given secondary metabolites into their respective chemical categories: Abrin, Concanavalin A, Codeine, and Curcumin.
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Consider the following statements regarding polysaccharides: (A) Cellulose is a homopolymer consisting only of glucose monomers. (B) Inulin is a fructosan polymer composed of fructose units. (C) In a polysaccharide chain such as glycogen, the right end is called the non-reducing end and the left end is the reducing end. (D) Starch forms helical secondary structures capable of holding \( \text{I}_2 \) molecules, whereas cellulose lacks complex helices and cannot hold \( \text{I}_2 \). Which of the above statements are correct?
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Match List-I with List-II: List-I (Enzyme Class) List-II (Catalysed Reaction Mechanism) A Transferases I Catalyse hydrolysis of ester, ether, peptide, or glycosidic bonds B Hydrolases II Catalyse transfer of a group (other than hydrogen) between substrates C Lyases III Catalyse linking together of two compounds with bond formation like C-O, C-S, C-N D Ligases IV Catalyse removal of groups from substrates leaving double bonds without hydrolysis Choose the correct answer from the options given below:
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Amino acids are classified based on the nature and chemical properties of their R functional groups. Which of the following correctly pairs an amino acid with its specific classification?
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Inulin is a storage polysaccharide found in certain plants. Structurally, inulin is a polymer of which monomer unit?
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Consider the following statements regarding factors affecting enzyme activity: (A) Every enzyme has an optimum pH and optimum temperature at which its activity is maximum. (B) Low temperature preserves the enzyme in a temporarily inactive state, whereas high temperature destroys enzymatic activity due to heat denaturation. (C) With an increase in substrate concentration, the velocity of the enzymatic reaction keeps rising indefinitely without reaching a maximum velocity (Vmax). (D) Competitive inhibitors closely resemble the substrate in structure and bind to the active site, thereby reducing enzyme activity. How many of the above statements are correct?
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Which of the following represents the correct descending order of biomolecules by percentage of total cellular mass in an average cell?
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In the absence of any enzyme, the reaction between \( \text{CO}_2 \) and \( \text{H}_2\text{O} \) produces approximately 200 molecules of \( \text{H}_2\text{CO}_3 \) per hour. When carbonic anhydrase is introduced, about 600,000 molecules are formed every second. By approximately what factor has the reaction rate been accelerated?
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When the concentration of substrate is progressively increased in an in vitro enzymatic assay, the reaction velocity initially rises and then reaches a plateau (\( V_{\max} \)). Why cannot the velocity be exceeded by further adding more substrate?
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The complex polysaccharide forming the exoskeleton of arthropods is chitin. What is the fundamental building unit of this homopolymer?
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The inhibition of succinic dehydrogenase by malonate is a classic example of competitive inhibition. Which of the following statements explains why this inhibition is competitive?
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The given diagrammatic representation illustrates various structural levels of proteins. Identify the structural level in which the long polypeptide chain is folded upon itself like a hollow woolen ball, which is absolutely necessary for the biological activities of proteins:
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According to the IUBMB classification system, which class of enzymes catalyzes the joining together of C-O, C-S, C-N, or P-O bonds?
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Starch gives a characteristic blue colour with iodine (I2), but pure cellulose does not. Reason (R): Starch forms helical secondary structures that can trap iodine molecules, whereas cellulose lacks complex helices and cannot hold I2. In the light of the above statements, choose the correct answer from the options given below:
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Examine the three graphs (a), (b), and (c) depicting the effect of various factors on enzyme activity. Which of the following correctly describes curve (c)?
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Starch gives a blue colour with iodine (\( \text{I}_2 \)), but cellulose does not give this test. What is the precise structural basis for this difference?
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In solutions of different pH, the electric charge and structure of an amino acid change dynamically. Reason (R): Amino acids possess ionizable functional groups, namely the amino (-NH2) and carboxyl (-COOH) groups. In the light of the above statements, choose the correct answer from the options given below:
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Consider the following statements regarding biomolecules and analytical fractions: (A) The acid-soluble pool represents roughly the cytoplasmic composition with compounds having molecular weights ranging from 18 to around 800 daltons. (B) The acid-insoluble fraction contains proteins, nucleic acids, polysaccharides, and lipids. (C) Lipids are strictly macromolecules having molecular weights exceeding 10,000 daltons. (D) Lipids appear in the acid-insoluble fraction because cell membranes break into water-insoluble vesicles during tissue grinding. Which of the above statements are correct?
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