Class 11 Biology - HARYANA
Biomolecules
The chapter 'Biomolecules' in Class 11 Biology explores the chemical composition of living tissues, focusing on the organic and inorganic compounds essential for life. Students learn about the structure, classification, and functions of carbohydrates, proteins, lipids, nucleic acids, and enzymes. This chapter is fundamental for understanding cellular metabolism, genetics, and physiology. For Haryana Board (BSEH) exams, it carries significant weightage with questions ranging from direct structural definitions to metabolic roles of enzymes, making it a high-scoring and crucial unit for both board exams and competitive medical entrances.
Start Learning FreeKey Concepts
Chemical Analysis of Tissue
Living tissue is ground in trichloroacetic acid to yield acid-soluble (micromolecules like amino acids) and acid-insoluble (macromolecules like proteins) fractions.
Proteins
Polymers of amino acids linked by peptide bonds, serving structural, transport, and enzymatic functions in living organisms.
Carbohydrates
Polyhydroxy aldehydes or ketones functioning as energy sources (glucose, starch) and structural components (cellulose, chitin).
Nucleic Acids
Polynucleotides including DNA and RNA composed of nitrogenous bases, pentose sugars, and phosphate groups, responsible for heredity and protein synthesis.
Enzymes
Biocatalysts, mostly proteins, that lower activation energy and speed up biochemical reactions without being consumed.
Important Formulas
Board Exam Info
In the Haryana (BSEH) Class 11 Biology board exams, Biomolecules typically carries around 4-6 marks. Common question types include 1-mark objective questions on enzyme action or bond types, 2-mark short answers on the difference between reducing and non-reducing sugars, and 3-mark diagrammatic or descriptive questions on the structure of proteins or nucleic acids.
Frequently Asked Questions
What is the difference between micromolecules and macromolecules?
Micromolecules have a molecular weight less than 1000 Daltons (e.g., amino acids, sugars) and are found in the acid-soluble pool. Macromolecules have a molecular weight greater than 1000 Daltons (e.g., proteins, nucleic acids) and are found in the acid-insoluble fraction.
Why are lipids not strictly considered macromolecules?
Although lipids have a molecular weight greater than 800 Da, their molecular weight does not exceed 1000 Da. When tissues are ground, lipid membranes form vesicles that separate into the acid-insoluble fraction, despite not being true polymers.
How do competitive inhibitors affect enzyme activity?
Competitive inhibitors resemble the substrate in structure and bind to the active site of the enzyme, blocking the actual substrate from binding and thereby decreasing enzyme activity, which can be overcome by increasing substrate concentration.
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