From: me22over7@gmail.com   
      
   What would it be like to walk around inside a cell? (In this example,   
   and human ovum.) This exercise may help you comprehend/intuit/appreciate   
   its workings better.   
      
      
   *The Scale*   
      
   If a nucleotide were the size of a tennis ball, a canonical amino acid   
   would match a golf ball, averaging 37 and 17 atoms respectively.   
      
   A mature human oocyte (ovum) is 7km diameter sphere, with a nucleus of   
   up to 2km, cell membrane roughly 0.5–0.7 metres thick.   
      
      
   *The City*   
      
   The interior is extremely crowded, but not solid—more like a dense,   
   moving fog of machinery.   
      
   There is no empty space at human scale; movement happens through   
   constantly shifting gaps.   
      
   Objects range from grapefruit-sized to skyscraper-sized, with the   
   overwhelming majority being small-to-medium machines.   
      
      
   *The Inhabitants*   
      
   A. Individual folded proteins (the dominant population), grapefruit →   
   soccer ball size; 100–300 amino acid; ~10¹¹–10¹² of them. They are   
   everywhere: cytoplasm, cortex, perinuclear region, appearing like a   
   dense swarm of autonomous robots, continuously bumping, binding, releasing.   
      
   B. Protein complexes (functional teams), e.g., transcription factors,   
   spliceosomes, signalling hubs; millions to tens of millions. Form   
   temporary clusters, especially near the nucleus, cytoskeletal tracks,   
   membrane regions. They are delivery trucks or small rooms that briefly   
   assemble, disassemble, and reassemble elsewhere.   
      
   C. Ribosomes (protein factories); hundreds of thousands to millions.   
   Dense in cytoplasm, sparse in nucleus; often found in clusters   
   (polysomes). Factories the size of small buildings, many operating in   
   parallel, with raw materials constantly arriving and finished products   
   immediately released into the crowd.   
      
   D. Cytoskeletal assemblies (infrastructure - actin filaments;   
   microtubules); hundreds of metres to kilometres. Forming dynamic   
   highways and scaffolding; continuously assembled and dismantled.   
   Suspension bridges and rail lines that reconfigure in real time while   
   traffic continues. With cargo hauled by motor proteins (themselves ~1 m   
   machines walking hand-over-hand).   
      
   E. Organelles. E.g. Mitochondrion (power & control district); ~1–2 km   
   long, ~300–500 m wide; tens to hundreds; outer wall: 0.6m thick, inner   
   wall: another 0.6 m thick, folded into cristae (folded walls forming   
   canyons and terraces tens of metres high). Enzymes: thousands of   
   soccer-ball-scale machines embedded in the walls; proton gradients   
   become pressure differentials; ATP synthase machines are rotary   
   turbines. Energy is not “stored” but continuously generated and spent. A   
   hydroelectric plant built inside a mountain, with internal tunnels   
   forcing flow in one direction only.   
      
   Or, the endoplasmic reticulum (manufacturing & logistics zone); several   
   kilometres of interconnected sheets and tubes, ~20–50m sheets. A   
   continuous membrane studded with ribosomes (~25m factories). Interior   
   (lumen); oxidising environment, chaperones everywhere, quality-control   
   checkpoints. Proteins are synthesised, folded, checked, rejected or   
   forwarded. A vast industrial park with assembly lines running directly   
   into enclosed inspection halls.   
      
   F. Nuclear interior (1.3–2 km inner sphere; chromatin fibres of 10–30m   
   thickness, thousands of kilometres long, tightly folded. Transcription   
   factories in ~50–100 m clusters, dozens to hundreds active at any time.   
   A dense industrial core, with massive cable bundles routed through   
   specialised production districts.   
      
      
   *The Wall*   
      
   ~0.6m thick lipid bilayer (fluid, deformable), with embedded proteins of   
   many sizes 1–10m. Receptors, channels, pumps, adhesion molecules;   
   thousands per 100m² of membrane. A living wall studded with doors,   
   valves, sensors, antennae, and rotating machines, all subtly drifting   
   laterally. Nothing is fixed in place.   
      
   Just beneath the membrane: the cortical zone, a protein meshwork   
   ~50–100m inward from the membrane. Comprises actin filaments (1–2 m   
   thick, hundreds of metres long); cross-linkers, regulatory proteins   
   Provides mechanical stiffness, shape control, polarity establishment,   
   signal amplification. A dense geodesic lattice pressed up against the   
   city wall, constantly tightening, loosening, and rearranging.   
      
      
   *The Experience*   
      
   Proteins occupy ~30–40% of volume. Water is the remaining “air”. Nothing   
   is dilute. Diffusion is like walking through a packed stadium, not   
   drifting in space. Weak interactions matter; spatial organisation   
   matters; timing and localisation are as important as sequence.   
      
   A living, self-modifying megacity — kilometres wide — built entirely of   
   moving molecular machines, with no central controller. Upon   
   fertilisation, going on to divide and differentiate countless times to   
   assemble a human.   
      
      
   *The Control*   
      
   For example, a city "block" is not executing a single “program.”   
   Instead, thousands of overlapping processes; no master clock; no central   
   dispatcher. Control arises from: concentration gradients, proximity,   
   binding affinities, mechanical constraints. Information is embodied, not   
   broadcast.   
      
      
   *The Conclusion*   
      
   For me, to marvel, and more. And you?   
      
      
   _____   
      
   Source: ChatGPT   
      
      
   Also: The Inner Life of the Cell Animation   
   https://www.youtube.com/watch?v=wJyUtbn0O5Y   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)