CSIR-NET LIFE SCIENCES

Unit 1: Structure and Function of Biomolecules

Complete Topic-Wise Syllabus

Biomolecules • Biophysical Chemistry • Bioenergetics • Enzymes • Proteins • Nucleic Acids • Metabolism

A. Structure of Atoms, Molecules and Chemical Bonds

1. Structure of Atoms

• Atomic number and mass number
• Protons, neutrons and electrons
• Isotopes, isobars and isotones
• Atomic orbitals
• Quantum numbers
• Electronic configuration
• Valence electrons
• Biologically important elements

2. Chemical Bonds

• Ionic bonds
• Covalent bonds
• Coordinate covalent bonds
• Polar and non-polar covalent bonds
• Single, double and triple bonds
• Bond length and bond strength
• Bond angle
• Electronegativity
• Dipole moment

3. Molecular Structure

• Lewis structures
• Resonance
• Formal charge
• Hybridization: sp, sp², sp³
• Molecular geometry
• VSEPR theory

🎯 CSIR-NET Focus: Electronegativity, polarity, resonance, hybridization, bond strength and molecular geometry.

B. Composition, Structure and Function of Biomolecules

🍬 Carbohydrates

• Monosaccharides, disaccharides and polysaccharides
• Aldoses and ketoses
• D and L configuration
• Fischer and Haworth projections
• Epimers and anomers
• Mutarotation
• Glycosidic bonds
• Reducing and non-reducing sugars
• Starch, glycogen, cellulose and chitin
• Glycosaminoglycans

🧈 Lipids

• Fatty acids
• Saturated and unsaturated fatty acids
• Cis and trans fatty acids
• Triacylglycerols
• Phospholipids
• Glycolipids
• Sphingolipids
• Cholesterol and steroids
• Membrane lipids

🧬 Proteins

• Amino acids
• Essential and non-essential amino acids
• Classification of amino acids
• Peptide bonds
• Primary, secondary, tertiary and quaternary structures
• Fibrous and globular proteins

🧬 Nucleic Acids

• Nucleotides and nucleosides
• Purines and pyrimidines
• DNA structure
• RNA structure
• Phosphodiester bonds
• Base pairing

💊 Vitamins

• Water-soluble vitamins
• Fat-soluble vitamins
• Vitamin B-complex
• Vitamin C
• Vitamin A, D, E and K
• Coenzyme functions
• Vitamin deficiency and toxicity

C. Stabilizing Interactions

Important Molecular Interactions

• 💧 Hydrogen bonding
• ⚡ Electrostatic interactions
• 🔗 Van der Waals interactions
• 💧 Hydrophobic interactions
• Dipole-dipole interactions
• Ion-dipole interactions
• Disulfide bonds
• Non-covalent interactions

Important: Understand how these interactions contribute to protein folding, nucleic acid structure, membrane formation and biomolecular stability.

D. Principles of Biophysical Chemistry

🧪 pH and Acids-Bases

• Acids and bases
• Strong and weak acids
• pH and pOH
• pK_a
• Ionization of weak acids and bases
• Henderson-Hasselbalch equation
• Isoelectric point

🧪 Buffers

• Buffer capacity
• Phosphate buffer
• Bicarbonate buffer
• Protein buffers
• Buffer preparation and calculations

📈 Reaction Kinetics

• Reaction rate
• Order of reaction
• Zero-order reactions
• First-order reactions
• Second-order reactions
• Rate constants
• Half-life
• Activation energy
• Arrhenius equation

🔥 Thermodynamics

• First law of thermodynamics
• Second law of thermodynamics
• Enthalpy
• Entropy
• Gibbs free energy
• ΔG, ΔH and ΔS
• Spontaneous and non-spontaneous reactions
• Equilibrium constant

💧 Colligative Properties

• Osmotic pressure
• Boiling point elevation
• Freezing point depression
• Vapour pressure lowering
• Osmosis

E. Bioenergetics and Biological Energy Transduction

⚡ Bioenergetics

• Free energy
• Standard free energy
• ATP as energy currency
• High-energy phosphate compounds
• Energy coupling
• Redox reactions
• Oxidation-reduction potential

🍞 Glycolysis

• Energy investment phase
• Energy payoff phase
• ATP production
• NADH production
• Substrate-level phosphorylation
• Regulation of glycolysis
• Fate of pyruvate

🔋 Oxidative Phosphorylation

• Electron Transport Chain
• Complex I
• Complex II
• Complex III
• Complex IV
• Ubiquinone
• Cytochrome c
• Proton gradient
• Proton motive force
• ATP synthase
• Chemiosmotic hypothesis

🔄 Coupled Reactions

• ATP hydrolysis
• Phosphoryl group transfer
• Redox coupling
• Thermodynamic coupling

F. Enzymes, Catalysis and Enzyme Kinetics

⚙️ Principles of Catalysis

• Activation energy
• Transition state
• Active site
• Enzyme specificity
• Transition-state stabilization

🧪 Mechanisms of Enzyme Catalysis

• Proximity and orientation
• Acid-base catalysis
• Covalent catalysis
• Metal ion catalysis
• Electrostatic catalysis

📊 Enzyme Kinetics

• Michaelis-Menten equation
• V_max
• K_m
• Turnover number
• Catalytic efficiency
• Michaelis-Menten plot
• Lineweaver-Burk plot

⛔ Enzyme Inhibition

• Competitive inhibition
• Non-competitive inhibition
• Uncompetitive inhibition
• Mixed inhibition
• Irreversible inhibition

🔄 Enzyme Regulation

• Allosteric regulation
• Feedback inhibition
• Covalent modification
• Phosphorylation
• Proteolytic activation

🧬 Isozymes

• Definition
• Structural differences
• Functional differences
• Tissue-specific expression
• Clinical significance

G. Conformation and Structure of Proteins

🧬 Protein Structure

• Primary structure
• Secondary structure
• Tertiary structure
• Quaternary structure

🌀 Secondary Structures

• α-helix
• β-sheet
• β-turns
• Loops
• Hydrogen bonding

📐 Ramachandran Plot

• Phi (φ) angle
• Psi (ψ) angle
• Allowed regions
• Disallowed regions
• Conformational restrictions
• Special properties of glycine and proline

🧩 Domains, Motifs and Folds

• Protein domains
• Functional domains
• Structural motifs
• Supersecondary structures
• Protein folds
• α-helical folds
• β-sheet folds
• α/β folds
• α+β folds

H. Conformation of Nucleic Acids

🧬 A-DNA

• Right-handed helix
• Helical pitch
• Base pairs per turn
• Major and minor grooves
• Biological significance

🧬 B-DNA

• Most common physiological DNA form
• Right-handed helix
• Base pairing
• Major and minor grooves
• Structural characteristics

🧬 Z-DNA

• Left-handed helix
• Zig-zag backbone
• GC-rich sequences
• Biological significance

📊 Comparison of A, B and Z DNA

• Helical direction
• Base pairs per turn
• Helical pitch
• Diameter
• Major and minor grooves
• Sugar conformation
• Glycosidic bond orientation

🧬 RNA Conformation

• RNA secondary structure
• Hairpin loops
• Stem-loop structures
• Bulges
• Internal loops
• RNA tertiary structure
• Non-canonical base pairing
• tRNA structure
• rRNA structure
• mRNA structural features

I. Stability of Proteins and Nucleic Acids

🧬 Protein Stability

• Hydrophobic interactions
• Hydrogen bonds
• Ionic interactions
• Van der Waals interactions
• Disulfide bonds
• Protein folding
• Protein unfolding
• Denaturation
• Renaturation

🌡️ Factors Affecting Protein Stability

• Temperature
• pH
• Ionic strength
• Solvent
• Chaotropic agents
• Urea
• Guanidinium chloride
• Reducing agents

🧬 Nucleic Acid Stability

• Hydrogen bonding
• Base stacking
• GC content
• Ionic strength
• DNA melting
• Melting temperature (T_m)
• DNA denaturation
• DNA renaturation
• DNA hybridization

J. Metabolism of Biomolecules

🍬 Carbohydrate Metabolism

• Glycolysis
• Gluconeogenesis
• Citric acid cycle
• Pentose phosphate pathway
• Glycogenesis
• Glycogenolysis
• Regulation of carbohydrate metabolism

🧈 Lipid Metabolism

• Fatty acid synthesis
• Fatty acid oxidation
• β-oxidation
• Ketone body metabolism
• Triacylglycerol metabolism
• Phospholipid metabolism
• Cholesterol biosynthesis
• Lipoprotein metabolism

🧬 Amino Acid Metabolism

• Transamination
• Deamination
• Decarboxylation
• Urea cycle
• Glucogenic amino acids
• Ketogenic amino acids
• Amino acid biosynthesis
• Amino acid degradation

🧬 Nucleotide Metabolism

• Purine biosynthesis
• Pyrimidine biosynthesis
• Purine degradation
• Pyrimidine degradation
• Salvage pathways
• Nucleotide interconversion
• dNTP synthesis

💊 Vitamin Metabolism

• Vitamin absorption
• Vitamin transport
• Vitamin storage
• Vitamin activation
• Vitamin-dependent enzymes
• Coenzyme functions
• Vitamin deficiency
• Vitamin toxicity

📚 CSIR-NET Unit 1 – Quick Revision Map

A → Atoms & Chemical Bonds

B → Biomolecules

C → Molecular Interactions

D → Biophysical Chemistry

E → Bioenergetics

F → Enzymes

G → Protein Conformation

H → Nucleic Acid Conformation

I → Biomolecular Stability

J → Metabolism

🎯 CSIR-NET Preparation Tip:
Give special attention to numerical problems from pH & buffers, thermodynamics, reaction kinetics and enzyme kinetics, and conceptual questions from protein structure, nucleic acids, bioenergetics and metabolic pathways.