The cytoplasm of a prokaryote has no membrane-bound organelles (unlike a eukaryote)
It has ribosomes, but these are slightly smaller (70S) than eukaryotic ribosomes (80S)
Some prokaryotes have a flagellum, which is a long, hair-like structure that rotates to make the cell move. Not all have one and some have a few
Doesn't have a nucleus - instead has a strand of circular DNA. Not attached to any histone proteins
Small loops of DNA called plasmids (similar to flagella, not always present) contain genes for antibiotic resistance and can be passed between other prokaryotes
Still has a plasma membrane
A cell wall is present and is made with murein, a glycoprotein
Some prokaryotes have a slime capsule to protect them from attack from the immune system
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Binary Fission
Used by prokaryotes
The circular DNA and plasmid(s) replicate. The main DNA loop is only replicated once, but plasmids can be replicated loads of times
The cell gets bigger and the DNA loops move to opposite poles of the cell
The cytoplasm begins to divide (and new cell walls begin to form)
The cytoplasm divides and two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but can have a variable number of copies of plasmids
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Viruses
Acellular - not a cell
Simply just nucleic acids surrounded by protein
Much smaller than bacteria, HIV is just 1um across
No plasma membrane, no cytoplasm and no ribosomes
They cannot reproduce on their own and need to reproduce inside cells
They use attachment proteins to bind to complementary receptor proteins on the surface of host cells
Different viruses have different attachment proteins and therefore can only hook onto one type of cell (some can infect a lot of different cells)
Because they're not alive, viruses don't undergo cell division - instead they inject their DNA or RNA into the host cell, then the cell uses its own organelles to replicate the viral particles
Viruses contain a core of genetic material - either DNA or RNA
The protein coat around the core is called the capsid
Attachment proteins stick out from the edge of the capsid
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