NCERT Exemplar Solutions for Class 11 Biology Chapter 9 Biomolecules
The NCERT Exemplar for Class 11 Biology Chapter 9, Biomolecules, is a key study resource that helps students understand the chemistry of life. This chapter deals with the molecules that form the basis of cellular structure and functions. From carbohydrates and proteins to nucleic acids and enzymes, students get a comprehensive view of how different biomolecules contribute to sustaining life. The NCERT Exemplar questions go beyond simple recall and encourage analytical and application-based thinking, making them vital for board exams and competitive exams like NEET.
The chapter begins with an introduction to the importance of biomolecules in living organisms. It highlights how organic and inorganic compounds together form the chemical basis of life. Exemplar questions test the ability to classify biomolecules, identify their monomers, and connect their structure with their biological functions.
Carbohydrates are studied as the primary source of energy. Students learn about monosaccharides like glucose, disaccharides like sucrose, and polysaccharides like starch and glycogen. Exemplar questions may include identifying reducing sugars, differentiating between storage and structural polysaccharides, and understanding the role of cellulose in plant cell walls.
Proteins are explained as the building blocks of the body, formed from amino acids. The chapter discusses the levels of protein structure—primary, secondary, tertiary, and quaternary. Exemplar questions test knowledge of peptide bonds, functional proteins such as enzymes and hormones, and structural proteins like collagen and keratin.
Lipids are studied for their role in energy storage, insulation, and cell membrane structure. Students are introduced to simple lipids (fats and oils), phospholipids, and steroids. Exemplar problems often ask about the amphipathic nature of phospholipids and their importance in membrane formation.
Nucleic acids—DNA and RNA—form another crucial topic. Students learn about their nucleotide composition, structure, and role in heredity and protein synthesis. Exemplar questions may involve identifying differences between DNA and RNA or understanding Chargaff’s rule in base pairing.
The chapter also focuses on enzymes, which act as biological catalysts. Students are introduced to enzyme-substrate interactions, the lock-and-key hypothesis, and the induced fit model. Exemplar questions often include factors affecting enzyme activity, such as temperature, pH, and concentration, as well as the significance of cofactors and coenzymes. Another important concept covered is metabolism, which includes catabolic and anabolic pathways. Exemplar problems test students’ understanding of metabolic intermediates and the significance of ATP as the energy currency of the cell. For effective preparation, students should carefully study the NCERT textbook tables and flowcharts summarizing biomolecules and their functions. Once the basics are clear, practicing Exemplar questions helps reinforce conceptual clarity and improve problem-solving accuracy. In summary, NCERT Exemplar Solutions for Class 11 Biology Chapter 9 Biomolecules provides a deep insight into the chemical foundation of life. By practicing the wide range of Exemplar questions, students can strengthen their theoretical understanding, build analytical skills, and perform confidently in both board and entrance exams.