Cells160-page6 - • Interior of Prokaryotic Cell • Single DNA molecule(circular concentrated in one area of the cytoplasm called a nucleoid The

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Cell - 6 Features of Prokaryotic Cells Generally very small and relatively simple (less than 5 μ m in diameter. External Features Boundary is the plasma membrane May have membrane infoldings called mesosomes Rigid wall composed of a unique substance, called Peptidoglycan, found only in the walls of the Bacteria (and absent in the Archaebacteria) May secrete a slime sheath or capsule for protection May have motile structures called flagella, but they are different from the flagella of eukaryotic cells. Their motion is caused by basal rotors. Some have tiny protein projections called pili, which help to attach bacteria to surfaces. Some hollow pili are used to transfer genetic material.
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Unformatted text preview: • Interior of Prokaryotic Cell • Single DNA molecule (circular), concentrated in one area of the cytoplasm called a nucleoid. The DNA is not surrounded by protein. Bacteria may have more than one copy of the DNA molecule. • May have plasmids, independent DNA fragments that carry specific pieces of genetic information. Plasmids can be transmitted from one bacterium to another, or from the environment to a bacterium. Plasmids are important in recombinant DNA research. • Cytoplasm • Ribosomes, composed of RNA and protein, of 70s density. • NO internal membrane-bounded structures (organelles)...
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This note was uploaded on 12/29/2011 for the course BIO 151 taught by Professor Edwards during the Spring '10 term at SUNY Stony Brook.

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