🦠 Structure of Prokaryotic Cells and of Viruses

Prokaryotic cells


Prokaryotes do not have a nucleus like eukaryotes do. Their DNA is not membrane-bound, just free in the cytoplasm. The extra features of prokaryotic cells vs. eukaryotic cells you must learn are:


-the cytoplasm overall does not contain membrane-bound organelles such as mitochondria and endoplasmic reticulum


-prokaryotic ribosomes are smaller than their eukaryotic counterparts


-as previously covered, and their primary defining element, they lack a nucleus; instead, their DNA is a single circular molecule freely present in the cytoplasm and not associated with any proteins such as histones in eukaryotes


-they have a cell wall which contains a special glycoprotein called murein (also known as peptidoglycan)


Some prokaryotes also go further to have some specialised parts, some seen in the diagram:


-one or more plasmids which are also circular DNA loops but much…

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