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A Tour Of The Cell - Coggle Diagram

- - - - Resolution vs magnification
        
        Resolution = minimum distance to distinguish two points
        
        Contrast improved by stains/phase-contrast
      - Light microscope
        
        Live cells possible
        
        ~200 nm limit
      - Electron microscope
        
        TEM: internal ultrastructure (thin sections, heavy-metal stain)
        
        SEM: surface topology (3D-like)
    - - Cell fractionation
        
        Homogenize → centrifuge
        
        Differential centrifugation
        
        Low g: nuclei/debris
        
        Medium g: mitochondria/chloroplasts
        
        High g: microsomes (ER/Golgi)
        
        Very high g: ribosomes
        
        Purpose: isolate parts to infer function
  - - - Prokaryotes: nucleoid, no membrane-bound organelles, smaller
      - Eukaryotes: organelles + compartmentalization, larger
    - - Double membrane; pore complex; nuclear lamina
      - Chromatin → chromosomes
      - Nucleolus = rRNA synthesis, ribosome assembly
    - - Free: cytosolic proteins
      - Bound (RER): secretion/endomembrane proteins
    - - Parts: nuclear envelope, ER, Golgi, lysosomes, vesicles, vacuoles, plasma membrane
      - Rough ER: bound ribosomes, glycoproteins, vesicles
      - Smooth ER: lipid synthesis, detox, Ca²⁺ storage
      - Golgi: cis receive, trans ship; modifies/sorts/tags
      - Lysosomes: acidic lumen; hydrolytic enzymes; autophagy; phagocytosis
      - Vacuoles: food/contractile; central vacuole (plants) for storage, turgor, growth
  - - - Double membrane; inner cristae ↑ area
      - Matrix: enzymes, mtDNA, ribosomes
      - Function: cellular respiration → ATP
    - - Double membrane; stroma
      - Thylakoids → grana; chlorophyll; photosynthesis
    - - Evidence: double membranes, circular DNA, 70S ribosomes, binary fission
  - - - Hollow; largest; centrosome/centrioles
      - Tracks for kinesin/dynein
      - Cilia/flagella with 9+2 arrangement
    - - Cell cortex; microvilli
      - Muscle contraction with myosin
      - Amoeboid movement; cytoplasmic streaming
    - - Fibrous (keratin); tension-bearing
      - Anchor nucleus; nuclear lamina
  - - - Primary wall; middle lamella (pectin); possible secondary wall
      - Cellulose microfibrils in matrix
    - - Collagen + proteoglycans + fibronectin
      - Integrins link ECM ↔ cytoskeleton (mechanotransduction)
    - - Plasmodesmata (plants): cytosol continuity
      - Tight junctions: seal; prevent leakage
      - Desmosomes: anchoring via intermediate filaments
      - Gap junctions: communication channels
  - - - Separates incompatible processes
      - Localizes enzymes/substrates
    - - Endomembrane trafficking → secretion
      - Cytoskeleton + motors → targeted transport
      - ECM/junctions → tissue-level coordination