1. Cytoplasmic (Cell) Membrane
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- Located just inside the peptidoglycan layer.
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- Phospholipid bilayer similar to eukaryotic membranes, but does not contain sterols (except Mycoplasma species).
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- Functions:
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- transport of molecules into cell
- energy generation by oxidative metabolism
- synthesis of cell wall precursors
- secretion of enzymes, toxins, and other proteins
- signal transduction
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2. Mesosome
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- Involved in cell division
3. Cytoplasm
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- contains the nucleoid and ribosomes, nutrient granules, metabolites and plasmids.
- Ribosomes
- Differ in size and composition from eukaryotic ribosomes—selective target of several antibiotics that inhibit bacterial, but not eukaryotic protein synthesis.
- Ribosomes
- contains the nucleoid and ribosomes, nutrient granules, metabolites and plasmids.
2. Granules
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- Several different types; stain characteristically and can be used to help identify some bacteria.
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3. Nucleoid
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- Location of bacterial DNA chromosome (~2000 genes, no introns)
- No nuclear membrane, no nucleolus, no mitotic spindle, no histones.
- Location of bacterial DNA chromosome (~2000 genes, no introns)
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4. Plasmids
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- Extrachromosomal double-stranded, circular DNA molecules.
- Replicate independently of bacterial chromosome.
- Found in Gram-positive and Gram-negative bacteria.
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2. Transposons
Photo by Open.Michigan