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🧫 The Cell: Structure & Function 🧫 (VenebleStudyGuide6) - Coggle…
🧫 The Cell: Structure & Function 🧫
(VenebleStudyGuide6)
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🔬 Microscopes
(PreLab Book)
• Light Microscopes 💡
• Brightfield (unstained) → plain view, like looking through clean glass → low contrast
• Brightfield (stained) → adds color contrast 🎨 but kills the cell
• Phase Contrast 🌫️ → live-cell mode → boosts internal detail without staining
• Fluorescence 🌈 → dyes glow under UV → like turning off the lights and seeing the city lights pop
• Confocal 🧠 → laser scans layer by layer → builds a crisp 3D “photo” of the cell
• Electron Microscopes ⚡
• SEM (Scanning) → shows surface texture → like topography for cells 🪩
• TEM (Transmission) → slices through → reveals inner blueprint 🧬
• Downside 🧍♂️ → both destroy samples, but detail = unmatched
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🧪 Cell Fractionation & Size
(VenableLectureNotes)
• Cell Fractionation ⚙️ → process that spins cells in a centrifuge to separate parts by weight
• Heaviest (nuclei) → middle (mitochondria) → lightest (ribosomes)
• Used to isolate organelles → kinda like “unpacking” a cell into pieces
• Example 🧫 → to study bacterial ribosomes, you’d break cells open → spin → collect the ribosome layer → test RNA
• Surface Area : Volume Ratio 📏 → smaller cells = more efficient exchange
• As cells grow, volume increases faster than surface area
• So instead of one big cell, organisms use many smaller ones — multicellular = efficiency + survival
• Think: a single big ice cube melts slow, but crushed ice melts fast = more surface exposed
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🧬 Prokaryotic vs Eukaryotic Cells(VenablePresentation6)
• Prokaryotic Cells 🦠 → small, simple, no nucleus (like a one-room setup — everything out in the open)
• DNA in cytoplasm (no folder, just floating)
• No organelles (bare minimum setup)
• Ex: bacteria, archaea (simple but effective)
• Eukaryotic Cells 🧫 → bigger, organized, has a nucleus (like a place with rooms — each section got a job)
• DNA inside nucleus (stored and protected)
• Has organelles → mitochondria, ER, Golgi, etc. (teamwork setup)
• Ex: plants, animals, fungi, protists (the complex crew)
🌱 Plant vs 🐾 Animal Cells
• Plant Cells → cell wall, chloroplasts, large vacuole (built for energy + storage)
• Animal Cells → no wall, smaller vacuoles, centrioles, lysosomes (built for movement + flexibility)
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🧫 Plasma Membrane & Nucleus
• Plasma membrane 🧱 → thin layer that controls what goes in or out (like a bouncer — only lets certain stuff through)
• Made of phospholipids + proteins (the wall and doors of the cell)
• “Sugar coating” 🍬 → called the glycocalyx → helps cells recognize each other (like a name tag)
• Nucleus 🧠 → cell’s control center (the main office)
• Holds DNA → the cell’s blueprint (the instruction manual)
• Nuclear membrane 🔒 → double layer with pores → controls what enters/exits (guarded door system)
• Allows RNA + small molecules through (important messages + supplies)
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📮 Golgi Apparatus & Lysosomes
• Golgi apparatus 🧳 → the cell’s sorting and shipping center. It takes proteins and lipids from the ER, edits them, then sends them where they need to go (like a warehouse that checks and ships orders)
• Transport vesicles 📦 → small carriers that move those finished products around the cell.
• Lysosomes ⚗️ → handle clean-up and recycling. They break down waste, old parts, or bacteria so the cell can reuse materials (like a repair shop that strips parts instead of tossing them)
• Enzymes inside do the breaking down through hydrolysis reactions.
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🧬 Energy & Maintenance Systems
• Mitochondria ⚡ → make ATP (cell energy) through cellular respiration (like the power plant of the cell)
• Chloroplasts 🌿 → found in plants, use sunlight to make food (solar panels that charge the system)
• Peroxisomes 💨 → break down fatty acids and detox chemicals (like air filters for the cell)
• ER + Golgi 🧳 → ER builds, Golgi modifies and ships materials (like a factory and packaging center working together)
• Lysosomes 🧹 → digest waste, old organelles, or bacteria (the clean-up crew that recycles parts)
• Vesicles 🚚 → transport cargo between organelles (delivery service keeping things moving)
• Endomembrane system 🌋 → all these parts linked together → builds, processes, and recycles materials
• Autophagy & Apoptosis ☠️ → autophagy = recycle old parts, apoptosis = programmed cell death (like cleaning house when it’s time to rebuild)
🕸️ Structure & Movement
• Cytoskeleton 🧵 → internal framework that keeps cell shape and moves stuff around (like the scaffolding + tracks inside a factory)
• Microtubules → thick rods for support and transport (train tracks for vesicles)
• Microfilaments → thin strands for movement (like ropes pulling the cell)
• Intermediate filaments → strong, stable fibers (the beams that hold everything steady)
• Motor proteins 🚴♂️ → move along the cytoskeleton carrying cargo (tiny delivery drivers)
• Centrosomes & Centrioles 🎯 → organize microtubules, key for cell division (like the anchor point when the cell splits)
• Cilia & Flagella 🌊 → hairlike or tail-like structures for movement (cilia = oars, flagella = propeller)
• Extracellular matrix 🧱 → network outside the cell for support + communication (like the pavement connecting buildings)
• Cell junctions 🔗 → hold cells together or let them share materials
• Tight junctions → seal things off (like zippers)
• Desmosomes → anchor cells (like rivets)
• Gap junctions → let small molecules pass (like tunnels)