prokaryote


prokaryote
prokaryotic /proh kar'ee ot"ik/, adj.
/proh kar"ee oht', -ee euht/, n.
any cellular organism that has no nuclear membrane, no organelles in the cytoplasm except ribosomes, and has its genetic material in the form of single continuous strands forming coils or loops, characteristic of all organisms in the kingdom Monera, as the bacteria and blue-green algae.
Also, procaryote. Cf. eukaryote.
[taken as sing. of NL Prokaryota, earlier Procaryotes (1925); see PRO-1, EUKARYOTE]

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Any cellular organism that lacks a distinct nucleus.

Bacteria (including blue-green algae, or cyanobacteria) are prokaryotes; all other organisms are eukaryotes. Prokaryotic cells lack a nuclear membrane and most of the components of eukaryotic cells. The cytoplasm includes ribosomes that carry out protein synthesis and a double-stranded DNA chromosome, usually circular. Many prokaryotes also contain additional circular DNA molecules called plasmids. The flagella are distinct from those of eukaryotes in design and movement.

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cell
also spelled  procaryote  
 any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes. Bacteria are among the best-known prokaryotic organisms. The lack of internal membranes in prokaryotes distinguishes them from eukaryotes (eukaryote). The prokaryotic cell membrane is made up of phospholipids and constitutes the cell's primary osmotic barrier. The cytoplasm contains ribosomes, which carry out protein synthesis, and a double-stranded deoxyribonucleic acid (DNA) chromosome, which is usually circular. Many prokaryotes also contain additional circular DNA molecules called plasmids (plasmid), with additional dispensable cell functions, such as encoding proteins to inactivate antibiotics. Some prokaryotes have flagella (flagellum). Prokaryotic flagella are distinct in design and movement from the flagella found on some eukaryotes. See also eukaryote; bacteria.

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Universalium. 2010.

Look at other dictionaries:

  • prokaryote — 1925, from Fr. procaryote, from Gk. pro (see PRO (Cf. pro )) + karyon “nut, kernel.” …   Etymology dictionary

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  • Prokaryote — The prokaryotes (pronEng|proʊˈkærioʊts; singular prokaryote IPA|/proʊˈkæriət/) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane bound organelles. They differ from the eukaryotes, which have a cell nucleus. Most… …   Wikipedia

  • prokaryote — also procaryote noun Etymology: New Latin Prokaryotes, proposed subdivision of protists, from 1pro + kary + otes, plural noun suffix, from Greek ōtos more at otic Date: 1963 any of the typically unicellular microorganisms that lack a distinct… …   New Collegiate Dictionary

  • prokaryote — noun a) an organism characterized by the absence of a nuclear membrane and by DNA that is not organized into chromosomes. b) in the of biological taxonomy, an organism of the kingdom (now superseded) …   Wiktionary

  • Prokaryote — Cell lacking a discrete nucleus and other special subcellular compartments. Bacteria and viruses are prokaryotes. Humans are not prokaryotes, but rather eukaryotes. * * * A member of the superkingdom Prokaryotae; an organismic unit consisting of… …   Medical dictionary

  • prokaryote —    A unicellular organism lacking a membranebound nucleus, for example, bacteria. Prokaryotes do not undergo mitosis …   Forensic science glossary

  • prokaryote — n. unicellular organism that does not have a nuclear membrane or cell organelles (such as bacteria and blue green algae) …   English contemporary dictionary

  • prokaryote — [prəʊ karɪəʊt, ɒt] (also procaryote) noun Biology a single celled organism with neither a distinct nucleus with a membrane nor other specialized structures (i.e. a bacterium or archaean). Compare with eukaryote. Derivatives prokaryotic adjective… …   English new terms dictionary

  • prokaryote — pro·kary·ote …   English syllables


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