penicillin

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noun pen·i·cil·lin \ˌpe-nə-ˈsi-lən\

Definition of penicillin

  1. 1 :  any of several relatively nontoxic antibiotic acids of the general formula C9H11N2O4SR that are produced by molds (genus Penicillium and especially P. notatum or P. chrysogenum) or synthetically and are used especially against gram-positive cocci; also :  a mixture of such acids

  2. 2 :  a salt or ester of a penicillin or a mixture of such salts or esters

Recent Examples of penicillin from the Web

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Origin and Etymology of penicillin

New Latin Penicillium

Other Biochemistry Terms


PENICILLIN Defined for English Language Learners

penicillin

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noun

Definition of penicillin for English Language Learners

  • : a medicine that is used to kill harmful bacteria


PENICILLIN Defined for Kids

penicillin

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noun pen·i·cil·lin \ˌpe-nə-ˈsi-lən\

Definition of penicillin for Students

  1. :  an antibiotic that is produced by a mold and is used against disease-causing bacteria


Medical Dictionary

penicillin

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noun pen·i·cil·lin \ˌpen-ə-ˈsil-ən\

Medical Definition of penicillin

  1. 1:  a mixture of relatively nontoxic antibiotic acids produced especially by molds of the genus Penicillium (as P. notatum or P. chrysogenum) and having a powerful bacteriostatic effect against various chiefly gram-positive bacteria (as staphylococci, gonococci, pneumococci, hemolytic streptococci, or some meningococci)

  2. 2:  any of numerous often hygroscopic and unstable amido acids (as penicillin G, penicillin O, and penicillin V) that have a structure in which a four-membered lactam ring shares a nitrogen and a carbon atom with a thiazolidine ring to which it is fused and that are components of the penicillin mixture or are produced biosynthetically by the use of different strains of molds or different media or are synthesized chemically

  3. 3:  a salt or ester of a penicillin acid or a mixture of such salts or esters


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