noun Biochemistry.

a deep-red iron-containing blood pigment, C34H32N4O4Fe, obtained from hemoglobin.

Nearby words

  1. hematotympanum,
  2. hematoxylin,
  3. hematoxylin-eosin stain,
  4. hematozoon,
  5. hematuria,
  6. hemel hempstead,
  7. hemelytron,
  8. hemeralopia,
  9. hemerocallis,
  10. hemet

Origin of heme

First recorded in 1920–25; shortened form of hematin

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for heme

  • Heme instantly drew forth a hunting-knife, and cutting Fenwolf's bonds asunder, the latter started to his feet.

    Windsor Castle|William Harrison Ainsworth

Medicine definitions for heme




The deep red, oxygen-carrying, nonprotein, ferrous component of hemoglobin.reduced hematin

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for heme



The deep red, nonprotein, iron-containing component of hemoglobin that carries oxygen. Heme is a porphyrin with an iron atom at its center. One of the free valence electrons of the iron atom of heme is bound to the hemoglobin molecule, while the other is available for binding to an oxygen atom. A hemoglobin molecule contains four hemes. Chemical formula: C34H32FeN4O4.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.