CSIR-NET LIFE SCIENCES

Unit 2: Cellular Organization

Complete Topic-Wise Syllabus

Cell Membrane • Organelles • Cytoskeleton • Genes & Chromosomes • Cell Cycle • Cell Death • Microbial Physiology

A. Cell Wall and Cell Membrane: Structure and Function

🧱 1. Cell Wall

• Structure and composition of bacterial cell wall
• Gram-positive cell wall
• Gram-negative cell wall
• Peptidoglycan structure
• Teichoic acids
• Lipopolysaccharides (LPS)
• Outer membrane
• Periplasmic space
• Archaeal cell wall
• Plant cell wall
• Primary and secondary cell walls
• Cellulose, hemicellulose and pectin
• Middle lamella
• Plasmodesmata

🧫 2. Model Membranes

• Structure of biological membranes
• Fluid mosaic model
• Lipid bilayer
• Membrane asymmetry
• Membrane fluidity
• Membrane thickness
• Effect of temperature on membrane fluidity
• Effect of cholesterol on membrane properties

🧈 3. Membrane Lipids

• Phospholipids
• Glycolipids
• Sphingolipids
• Cholesterol
• Archaeal membrane lipids
• Membrane lipid composition in prokaryotes and eukaryotes

🧬 4. Membrane Proteins

• Integral membrane proteins
• Peripheral membrane proteins
• Transmembrane proteins
• Single-pass and multipass proteins
• Membrane protein domains
• Membrane receptors
• Transport proteins

💧 5. Passive Transport

• Simple diffusion
• Facilitated diffusion
• Concentration gradient
• Electrochemical gradient
• Osmosis
• Water potential
• Channel-mediated transport

🚪 6. Ion Channels

• Ion channel structure
• Ion selectivity
• Voltage-gated channels
• Ligand-gated channels
• Mechanically gated channels
• Ion channel regulation
• Channel opening and closing

⚡ 7. Active Transport

• Primary active transport
• Secondary active transport
• Uniport
• Symport
• Antiport
• Na⁺/K⁺ ATPase
• Ca²⁺ pumps
• H⁺ pumps

🔄 8. Membrane Pumps

• P-type ATPases
• V-type ATPases
• F-type ATPases
• ABC transporters
• Proton pumps
• Ion pumps

📦 9. Intracellular Transport

• Protein targeting
• Signal sequences
• Vesicular transport
• Endocytosis
• Exocytosis
• Clathrin-mediated transport
• COPI and COPII vesicles
• SNARE proteins
• Rab proteins
• Intracellular sorting mechanisms

⚡ 10. Electrical Properties of Membranes

• Membrane potential
• Resting membrane potential
• Electrochemical gradient
• Nernst equation
• Ion equilibrium potential
• Action potential
• Depolarization
• Repolarization
• Hyperpolarization

🎯 CSIR-NET Focus:
Fluid mosaic model, membrane transport, ion channels, Na⁺/K⁺ ATPase, membrane potential, Nernst equation and intracellular protein sorting are highly important.

B. Structural Organization and Function of Intracellular Organelles

🧬 1. Nucleus

• Nuclear envelope
• Outer and inner nuclear membranes
• Nuclear pore complex
• Nuclear transport
• Nuclear localization signals
• Nucleoplasm
• Nucleolus
• Chromatin organization
• Nuclear lamina
• Nucleus dynamics during cell division

⚡ 2. Mitochondria

• Outer mitochondrial membrane
• Inner mitochondrial membrane
• Intermembrane space
• Mitochondrial matrix
• Electron transport chain
• Oxidative phosphorylation
• Mitochondrial DNA
• Mitochondrial protein import
• Endosymbiotic origin
• Mitochondrial dynamics
• Fusion and fission

📦 3. Golgi Apparatus

• Cis-Golgi network
• Medial Golgi
• Trans-Golgi network
• Protein modification
• Protein sorting
• Glycosylation
• Vesicular transport
• Lysosomal enzyme targeting

♻️ 4. Lysosomes

• Lysosomal structure
• Acidic lumen
• Acid hydrolases
• Intracellular digestion
• Endocytosis
• Phagocytosis
• Autophagy

🧪 5. Endoplasmic Reticulum

• Rough ER
• Smooth ER
• Protein synthesis
• Protein folding
• Protein modification
• Lipid synthesis
• Calcium storage
• ER stress
• Unfolded protein response

🔬 6. Peroxisomes

• Peroxisomal structure
• Hydrogen peroxide metabolism
• Catalase
• Fatty acid oxidation
• Plasmalogen synthesis
• Protein targeting to peroxisomes

🌱 7. Plastids

• Chloroplasts
• Chromoplasts
• Leucoplasts
• Amyloplasts
• Plastid genome
• Plastid inheritance

🌿 8. Chloroplast

• Outer membrane
• Inner membrane
• Stroma
• Thylakoid membrane
• Grana
• Stroma lamellae
• Photosystems
• Electron transport
• ATP synthesis
• Calvin cycle
• Chloroplast DNA
• Endosymbiotic origin

💧 9. Vacuoles

• Vacuolar membrane / tonoplast
• Storage functions
• Ion storage
• Water balance
• Cell turgor
• Waste storage
• Plant cell vacuoles

🧵 10. Cytoskeleton

• Microfilaments
• Intermediate filaments
• Microtubules
• Actin
• Myosin
• Tubulin
• Kinesin
• Dynein
• Dynamic instability
• Centrosomes
• Centrioles

🏃 11. Cytoskeleton and Cell Motility

• Muscle contraction
• Cell migration
• Actin-based movement
• Ciliary movement
• Flagellar movement
• Microtubule-based transport
• Motor proteins
• Axonal transport

💡 Remember:
Microfilaments → Actin → Cell movement
Microtubules → Tubulin → Vesicle transport and chromosome movement
Intermediate filaments → Mechanical strength

C. Organization of Genes and Chromosomes

🧬 1. Gene Organization

• Gene structure
• Promoters
• Enhancers
• Silencers
• Regulatory sequences
• Transcription units
• Exons and introns
• 5′ and 3′ untranslated regions

🔬 2. Operons

• Concept of operon
• Prokaryotic gene regulation
• Lac operon
• Trp operon
• Inducible operons
• Repressible operons
• Positive and negative regulation

🧬 3. Unique and Repetitive DNA

• Unique DNA sequences
• Moderately repetitive DNA
• Highly repetitive DNA
• Tandem repeats
• Satellite DNA
• Minisatellites
• Microsatellites
• Interspersed repetitive sequences

🧩 4. Interrupted Genes

• Exons
• Introns
• RNA splicing
• Alternative splicing
• Spliceosome
• Self-splicing introns

👨‍👩‍👧 5. Gene Families

• Definition of gene families
• Gene duplication
• Sequence homology
• Paralogs
• Orthologs
• Globin gene family
• Histone gene families

🧬 6. Chromatin Organization

• Nucleosomes
• Histone proteins
• Histone H2A, H2B, H3 and H4
• Histone H1
• DNA wrapping around histones
• Chromatin remodeling
• Histone modifications
• DNA methylation

🔵 7. Euchromatin

• Less condensed chromatin
• Transcriptionally active regions
• Gene-rich regions
• Open chromatin

⚫ 8. Heterochromatin

• Highly condensed chromatin
• Transcriptionally inactive regions
• Constitutive heterochromatin
• Facultative heterochromatin
• Centromeric DNA
• Telomeric DNA

🧬 9. Transposons

• Mobile genetic elements
• DNA transposons
• RNA transposons
• Retrotransposons
• Autonomous and non-autonomous elements
• Transposase
• Insertion sequences
• Role of transposons in genome evolution

🎯 CSIR-NET Focus:
Lac operon, Trp operon, nucleosome organization, euchromatin vs heterochromatin, repetitive DNA, gene families and transposable elements are important areas.

D. Cell Division and Cell Cycle

🔄 1. Cell Cycle

• G₁ phase
• S phase
• G₂ phase
• M phase
• G₀ phase
• Cell cycle checkpoints

🧬 2. Cell Cycle Regulation

• Cyclins
• Cyclin-dependent kinases (CDKs)
• CDK inhibitors
• Restriction point
• G₁/S checkpoint
• G₂/M checkpoint
• Spindle assembly checkpoint
• p53
• Rb protein

🧬 3. Mitosis

• Prophase
• Prometaphase
• Metaphase
• Anaphase
• Telophase
• Cytokinesis
• Mitotic spindle
• Kinetochore
• Chromosome segregation

🧬 4. Meiosis

• Meiosis I
• Meiosis II
• Prophase I
• Leptotene
• Zygotene
• Pachytene
• Diplotene
• Diakinesis
• Crossing over
• Synaptonemal complex
• Genetic recombination
• Reduction division

☠️ 5. Apoptosis

• Programmed cell death
• Intrinsic pathway
• Extrinsic pathway
• Caspases
• Caspase cascade
• Bcl-2 family
• Mitochondrial pathway
• Cytochrome c release
• Apoptosome

💥 6. Necrosis

• Uncontrolled cell death
• Cell swelling
• Membrane rupture
• Inflammatory response
• Differences between apoptosis and necrosis

♻️ 7. Autophagy

• Macroautophagy
• Microautophagy
• Chaperone-mediated autophagy
• Autophagosome
• Lysosome fusion
• Cellular recycling
• Role during starvation and stress

📌 Important Comparison:
Mitosis: Growth, repair and asexual reproduction
Meiosis: Gamete formation and genetic variation
Apoptosis: Programmed cell death
Necrosis: Cell injury-associated death
Autophagy: Cellular recycling and degradation

E. Microbial Physiology

🦠 1. Microbial Growth

• Microbial growth
• Growth curve
• Lag phase
• Log / exponential phase
• Stationary phase
• Death phase
• Generation time
• Growth rate
• Doubling time
• Batch culture
• Continuous culture

📈 2. Growth Kinetics

• Specific growth rate
• Generation time calculation
• Monod equation
• Substrate limitation
• Chemostat
• Turbidostat
• Biomass production

🦠 3. Strategies of Cell Division

• Binary fission
• Budding
• Multiple fission
• Filamentous growth
• FtsZ and bacterial cytokinesis
• Septum formation
• Cell division regulation

🛡️ 4. Microbial Stress Response

• Heat shock response
• Cold shock response
• Oxidative stress
• Osmotic stress
• Acid stress
• Nutrient limitation
• Starvation response
• Stress proteins
• Heat shock proteins
• Stringent response

💊 5. Antimicrobial Resistance

• Definition of antimicrobial resistance
• Intrinsic resistance
• Acquired resistance
• Mutation-mediated resistance
• Horizontal gene transfer
• Transformation
• Transduction
• Conjugation

🛡️ 6. Mechanisms of Antimicrobial Resistance

• Drug inactivation
• Target modification
• Target protection
• Reduced drug uptake
• Efflux pumps
• Biofilm-mediated resistance
• Enzymatic degradation of antibiotics
• Alteration of metabolic pathways

🎯 CSIR-NET Focus:
Microbial growth curve, generation time, growth kinetics, Monod equation, bacterial cell division, stress responses and mechanisms of antimicrobial resistance should be studied thoroughly.

📚 CSIR-NET Unit 2 – Quick Revision Map

A → Cell Wall & Cell Membrane

B → Organelles & Cytoskeleton

C → Genes & Chromosomes

D → Cell Cycle & Cell Division

E → Microbial Physiology

🎯 High-Yield CSIR-NET Topics

• Fluid mosaic model and membrane transport
• Ion channels and membrane potential
• Na⁺/K⁺ ATPase
• Protein sorting and vesicular transport
• Mitochondria and chloroplast structure
• Cytoskeleton and motor proteins
• Lac operon and Trp operon
• Nucleosome and chromatin organization
• Euchromatin vs heterochromatin
• Transposons and repetitive DNA
• Mitosis and meiosis
• Cell-cycle checkpoints and CDKs
• Apoptosis, necrosis and autophagy
• Microbial growth curve and growth kinetics
• Antimicrobial resistance mechanisms

📖 Study Order Recommendation:
Cell Membrane → Organelles → Cytoskeleton → Genes & Chromosomes → Cell Cycle → Cell Death → Microbial Growth → Stress Response → Antimicrobial Resistance