 nucleoid
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| In prokaryotes, the nucleoid (meaning nucleus-like and also known as the nuclear region, nuclear body or chromatin body) is an irregularly-shaped region within the cell of prokaryotes where the genetic material is localized. The nucleic acid is a circular, double-stranded piece of DNA, and multiple copies may exist. This method of genetic storage can be contrasted against that of the eukaryotes, where DNA is packed into chromatins and sequestered within a membrane-enclosed organelle called the nucleus.
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| mesosome
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| Mesosomes are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy. Although several functions were proposed for these structures in the 1960s, they were recognized as artifacts by the late 1970s and are no longer considered to be part of the normal structure of bacterial cells.
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| cytoplasm
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| Cytoplasm is a gelatinous, semi-transparent fluid that fills much of the volume of cells. Eukaryotic cells contain organelles, such as mitochondria that are filled with liquid that is kept separate from the cytoplasm by cell membranes.
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| flagellum
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| A flagellum (plural: flagella) is a tail-like structure that projects from the cell body of certain prokaryotic and eukaryotic cells, and it functions in locomotion.
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| ribosome
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| Ribosomes (from ribonucleic acid and "Greek: soma (meaning body)") are complexes of RNA and protein that are found in all cells. Prokaryotic ribosomes from archaea and bacteria are smaller than most of the ribosomes from eukaryotes such as plants and animals. However, the ribosomes in the mitochondrion of eukaryotic cells resemble those in bacteria, reflecting the evolutionary origin of this organelle.
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| plasma membrane
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| The Cell Membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer") is a selectively permeable lipid bilayer found in all cells. It contains a wide variety of biological molecules, primarily proteins and lipids, which are involved in a vast array of cellular processes such as cell adhesion, ion channel conductance and cell signaling. The plasma membrane also serves as the attachment point for both the intracellular cytoskeleton and, if present, the cell wall
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| cell wall
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| A cell wall is a fairly rigid layer surrounding a cell, located external to the cell membrane, which provides the cell with structural support, protection, and acts as a filtering mechanism. The cell wall also prevents over-expansion when water enters the cell. They are found in plants, bacteria, archaea, fungi, and algae. Animals and most protists do not have cell walls.
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| capsule
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| capsule in microbiology refers to a layer that lies outside the cell wall of bacteria. This layer is well organized and not easily washed off. It is usually composed of polysaccharides. Capsules help protect bacteria against phagocytosis. Capsules also contain water which protects bacteria against desiccation. They also exclude bacterial viruses and most hydrophobic toxic materials such as detergents.
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 prokaryote
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| an organism characterized by the absence of a nuclear membrane and by DNA that is not organized into chromosomes.
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| eukaryote
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| Any of the single-celled or multicellular organisms whose cells contain at least one distinct nucleus.
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