What do a.m. and p.m. stand for?


[heem] /him/
noun, Biochemistry
a deep-red iron-containing blood pigment, C 34 H 32 N 4 O 4 Fe, obtained from hemoglobin.
Origin of heme
1920-25; shortened form of hematin Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for heme
  • What she found instead was evidence of heme in the bones-additional support for the idea that they were red blood cells.
  • With red meat, it may be the high amount of heme iron, he says.
  • Second, the enzyme deficiency prevents them from breaking down toxic protein precursors of heme, called porphyrins.
  • They put a smaller structure inside it called a heme, a large flat molecule that is the active part of hemoglobin.
  • Iron found in foods is either in the form of heme or non-heme iron.
British Dictionary definitions for heme


(biochem) a complex red organic pigment containing ferrous iron, present in haemoglobin
Word Origin
C20: shortened from haematin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
heme in Medicine

heme (hēm)
The deep red, oxygen-carrying, nonprotein, ferrous component of hemoglobin. Also called reduced hematin.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
heme in Science
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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for heme

Most English speakers likely know this word

Word Value for heme

Scrabble Words With Friends