Class 12 Chemistry - PUNJAB
Biomolecules
The chapter 'Biomolecules' in Class 12 Chemistry explores the chemical basis of life, focusing on the structure, classification, and functions of essential organic compounds in living systems. Punjab (PSEB) students will study carbohydrates, proteins, nucleic acids, vitamins, and lipids. Carbohydrates like glucose and fructose are analyzed alongside their ring structures and glycosidic linkages. Proteins are studied through amino acids and peptide bonds, detailing primary, secondary, tertiary, and quaternary structures. Nucleic acids (DNA and RNA) explain heredity and protein synthesis. This chapter is vital for board exams as it features high-scoring direct questions, structural differences, and structural identification problems.
Start Learning FreeKey Concepts
Carbohydrates
Optically active polyhydroxy aldehydes or ketones, classified as monosaccharides, oligosaccharides, and polysaccharides based on hydrolysis behavior.
Amino Acids and Proteins
Proteins are polymers of alpha-amino acids linked by peptide bonds, existing as zwitterions in aqueous solutions due to acidic and basic functional groups.
Nucleic Acids
Polymers of nucleotides consisting of a pentose sugar, a nitrogenous base, and a phosphate group, responsible for genetic information storage and transfer (DNA and RNA).
Enzymes
Biocatalysts, mostly globular proteins, that speed up biochemical reactions in living organisms with high specificity and efficiency.
Vitamins
Organic compounds required in small amounts for normal health, growth, and development, classified into fat-soluble (A, D, E, K) and water-soluble (B-complex, C).
Important Formulas
Board Exam Info
In the Punjab (PSEB) Class 12 Chemistry board exam, Biomolecules typically carries around 4 to 6 marks. Questions usually include short answer questions on zwitter ions, denaturation of proteins, differences between DNA and RNA, classification of carbohydrates, and vitamin deficiency diseases.
Frequently Asked Questions
What is a zwitter ion?
It is a dipolar ion formed when a hydrogen ion moves from the carboxylic acid group to the amino group within an amino acid, resulting in both positive and negative charges.
What is the difference between alpha-helix and beta-pleated sheet structures?
In an alpha-helix, the polypeptide chain coils into a right-handed screw held by hydrogen bonds, whereas in a beta-pleated sheet, chains are stretched out side by side and held together by intermolecular hydrogen bonds.
Why are vitamin C and B-complex vitamins not stored in our bodies?
They are water-soluble vitamins, meaning they dissolve in water and are regularly excreted in urine, so they must be supplied regularly through diet.
Learn Biomolecules with Your AI Tutor
10 different ways to study this chapter. Free for 3 chapters per day.
Lecture
Key Points
Interactive
Quiz
Flashcards