🧬 Eukaryotic Cytoskeleton – Types, Structure, and NEET Insights

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🔍 1. What is the Cytoskeleton?

The cytoskeleton is a dynamic network of protein filaments found throughout the cytoplasm of eukaryotic cells. It provides shape, support, movement, and internal organization to the cell.


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🧫 2. Components of Cytoskeleton

Component Size Protein Function

Microtubules ~25 nm Tubulin Cell shape, chromosome movement, cilia & flagella
Microfilaments ~7 nm Actin Cell movement, muscle contraction, cytokinesis
Intermediate Filaments ~10 nm Keratin, vimentin, etc. Mechanical strength, cell stability



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📘 Mnemonic to Remember

🧠 “MIC-MIC-IN”

MICrotubules – Largest

MICrofilaments – Smallest

INtermediate – In between



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🌀 3. Functions of Cytoskeleton

🧍 Maintains cell shape and structure

🚶‍♂️ Helps in intracellular transport of organelles

🧬 Chromosome movement during cell division

✂️ Cytokinesis (division of cytoplasm)

🧭 Guides vesicle movement and organelle positioning



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🔍 4. Special Roles

Component Special Function

Microtubules Spindle fibers during mitosis
Microfilaments Amoeboid movement, cleavage furrow
Intermediate Filaments Nuclear lamina formation



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🧪 NEET Focus Points

✅ Microtubules = tubulin + 25 nm
✅ Microfilaments = actin + 7 nm
✅ Intermediate filaments are not involved in motility

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