- any of several carrier molecules in the mitochondria of plant and animal cells, consisting of a protein and an iron-containing porphyrin ring and participating in the stepwise transfer of electrons in oxidation reactions: each cytochrome alternately accepts and releases an electron at a slightly lower energy level in the order designated b, c1, c, a, and a3.
Compare electron transport.
Origin of cytochrome
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- any of a group of naturally occurring compounds, consisting of iron, a protein, and a porphyrin, that are important in cell oxidation-reduction reactions
- Any of a class of iron-containing proteins important in cell respiration as catalysts of oxidation-reduction reactions.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- Any of a class of usually colored proteins that play important roles in oxidative processes and energy transfer during cell metabolism and cellular respiration. Cytochromes are electron carriers. They contain a heme group and are similar in structure to hemoglobin and chlorophyll. The most abundant and stable type is cytochrome c. By comparing different kinds of cytochromes, scientists can trace the evolutionary relationships of the organisms in which they occur.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.