17 lines
926 B
Markdown
17 lines
926 B
Markdown
[[Cell Structure and Function]]
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# Summary
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* Selective permeability comes from hydrophobic interior of nuclear membrane since phospholipids have fatty acid tails which are non polar
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* Small non polar molecules ($N_2,O_2,CO_2$) pass through freely
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* Small non charged polar molecules ($H_2O,NH_3$) can slip through in small amounts
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* Ions and and large polar molecules can't cross and require channels or transport proteins.
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* Cell walls in bacteria, archaea, fungi and plants provides structure, protects against osmotic lysis and acts as a permeability layer for some substances.
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![[Pasted image 20260817121113.png]]![[Pasted image 20260817121129.png|526]]
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Cell wall material:
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* Bacteria - peptidoglycan
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* Archaea - various polymers (not peptidoglycan)
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* Fungi - chitin
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* Plants - cellulose
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Cell walls maintain shape and mechanical strength, permeability layer, protection from osmotic lysis (rupture via influx of water).
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