Macromolecules and Polymeric Structure — NEET Biology
📚 Practice ConceptOnly three types of macromolecules, i.e., proteins, nucleic acids and polysaccharides are found in living systems. Lipids, because of their association with membranes separate in the macromolecular fraction. Biomacromolecules are polymers. They are made of building blocks which are different. Proteins are heteropolymers made of amino acids. Nucleic acids (RNA and DNA) are composed of nucleotides. Biomacromolecules have a hierarchy of structures –
Which of the above statements are correct about biomacromolecules? S1: Biomacromolecules are typically found in the acid-insoluble fraction, also known as the retentate, after chemical analysis of living tissue. S2: All biomacromolecules, including lipids, are polymers with molecular weights generally exceeding 10,000 daltons. S3: Proteins, nucleic acids, and polysaccharides are true polymeric biomacromolecules, with their respective monomers being amino acids, nucleotides, and monosaccharides. S4: The acid-soluble pool primarily contains micromolecules with molecular weights ranging from 18 to approximately 800 daltons. S5: Lipids are unique among the compounds of the acid-insoluble fraction because they are not strictly macromolecules but are included due to their association with disrupted cellular membranes. S6: Ribulose bisphosphate Carboxylase-Oxygenase (RuBisCO) is the most abundant protein in the animal world, exemplifying a functional biomacromolecule.
View solution & NCERT explanation
Correct answer: A — S1, S3, S4 and S5 only
The question evaluates the understanding of the general characteristics of biomacromolecules, their classification in pools, and exceptions. S1: Biomacromolecules, by definition, are the organic compounds found in the acid-insoluble fraction (retentate) during chemical analysis. This statement is correct. (NCERT Page 108, Para 3) S2: This statement is incorrect. While most biomacromolecules (proteins, nucleic acids, polysaccharides) are polymers with high molecular weights, lipids are explicitly stated as an exception. Lipids are not strictly macromolecules and have low molecular weights (not exceeding 800 Da), yet they are found in the acid-insoluble fraction. (NCERT Page 108, Para 3-4; Page 109, Para 1) S3: Proteins are polymers of amino acids, nucleic acids are polymers of nucleotides, and polysaccharides are polymers of monosaccharides. These are indeed true polymeric biomacromolecules. This statement is correct. (NCERT Page 109, Para 2-3; Page 110, Para 2; Page 111, Para 2) S4: The acid-soluble pool (filtrate) contains micromolecules, which are small molecular weight compounds with molecular weights typically ranging from 18 to around 800 daltons. This statement is correct. (NCERT Page 108, Para 3) S5: Lipids are indeed unique in the acid-insoluble fraction because they are small molecular weight compounds, not strict macromolecules, but their presence is due to their aggregation into non-water-soluble membrane vesicles upon cell disruption. This statement is correct. (NCERT Page 108, Para 4; Page 109, Para 1) S6: Ribulose bisphosphate Carboxylase-Oxygenase (RuBisCO) is the most abundant protein in the whole of the biosphere, while collagen is the most abundant protein in the animal world. Therefore, this statement is incorrect. (NCERT Page 110, Para 1) Thus, statements S1, S3, S4, and S5 are correct. Final Answer: The final answer is A. S1, S3, S4 and S5 only
What does NCERT say about Only three types macromolecules?
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