Definition of "cytochrome" [cytochrome]

• Any of a class of iron-containing proteins important in cell respiration as catalysts of oxidation-reduction reactions. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Researchers found differences in 10 genes around an enzyme called cytochrome P450 1b1, which is known to break down estrogen and tobacco smoke."
• "Humans have an enzyme called cytochrome P450 3A4 that helps to metabolize calcium channel blockers and clear them from the system."
• "They all belong to a major family of enzymes called cytochrome P450 that act as a catalyst for a broad range of chemical reactions and are implicated in pesticide resistance in other insect species."