Heme vs. Haem — What's the Difference?
By Fiza Rafique & Urooj Arif — Updated on May 1, 2024
Heme and haem refer to the same iron-containing molecule essential for blood function; "heme" is the preferred spelling in American English, while "haem" is used in British English.
Difference Between Heme and Haem
Table of Contents
ADVERTISEMENT
Key Differences
Heme, as used in American English, denotes an iron-containing porphyrin, crucial for oxygen transport in the blood via hemoglobin. On the other hand, haem, as spelled in British English, represents the same molecular structure and serves identical biological functions.
In scientific contexts, "heme" is often paired with American terminology in medical and biological sciences, such as in the naming of heme-related enzymes and proteins. Whereas, "haem" is associated with the same concepts but aligns with British nomenclature like "haemoglobin" instead of "hemoglobin".
The pronunciation of "heme" typically follows the American English phonetic pattern, emphasizing a direct and concise pronunciation. Conversely, "haem" may be pronounced slightly differently in British English, reflecting its orthographic tradition.
The usage of "heme" versus "haem" can also indicate the origin of scientific literature or the educational background of a speaker or author. Whereas, the use of "haem" suggests adherence to British standards and may influence the spelling of related compounds and processes.
Both terms are used interchangeably in international scientific literature, depending on the audience and publication standards. However, "haem" is often used in commonwealth countries, reflecting broader linguistic variations.
ADVERTISEMENT
Comparison Chart
Spelling
American English
British English
Pronunciation
/hiːm/
/hiːm/
Usage Context
American literature
British literature
Educational Influence
American schools
British schools
Associated Terms
Hemoglobin, heme oxygenase
Haemoglobin, haem oxygenase
Compare with Definitions
Heme
Can be synthesized artificially for medical uses.
Synthetic heme is used in some types of treatments for anemia.
Haem
A component of haemoglobin that contains iron.
Haem is essential for oxygenation of the body's tissues.
Heme
Found in the blood of animals.
The heme levels in his blood were tested to assess his health.
Haem
Gives haemoglobin its red color.
The red color of haemoglobin is due to the haem group.
Heme
Crucial for various biological processes.
Heme is involved in the process of cellular respiration.
Haem
Involved in oxidative metabolic pathways.
Haem plays a part in oxidizing enzymes within the electron transport chain.
Heme
An iron-containing molecule in hemoglobin.
Heme plays a critical role in transporting oxygen through the blood.
Haem
Synthetic forms are used in supplements and drugs.
Haem iron supplements are popular for their high bioavailability.
Heme
Associated with the coloration of blood.
Heme gives blood its characteristic red color.
Haem
Present in vertebrate and some invertebrate animals.
They studied the haem content in different species of mollusks.
Heme
Heme, or haem (spelling differences) is a substance precursive to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver.In microbiological terms, heme is coordination complex "consisting of an iron ion coordinated to a porphyrin acting as a tetradentate ligand, and to one or two axial ligands." The definition is loose, and many depictions omit the axial ligands.
Haem
Variant of heme.
Heme
A deep red, iron-containing compound, C34H32FeN4O4, that constitutes the nonprotein component of hemoglobin and certain other proteins.
Haem
Standard spelling of from2=Canada
Heme
(biochemistry) The component of hemoglobin (and other hemoproteins) responsible for binding oxygen. It consists of an iron ion that binds oxygen and a porphyrin ring that binds the globin molecules; one molecule binds one molecule of oxygen.
Haem
A complex red organic pigment containing iron and other atoms to which oxygen binds
Heme
A complex red organic pigment containing iron and other atoms to which oxygen binds
Common Curiosities
What is the function of heme/haem in the body?
Heme or haem functions primarily to bind oxygen in the bloodstream through hemoglobin.
Can the spelling of heme/haem affect its interpretation in scientific research?
The spelling does not affect the scientific interpretation but can indicate the regional origin of the research.
Why are there two different spellings for heme/haem?
The difference in spelling reflects variations between American and British English.
Are heme and haem chemically different?
No, heme and haem are chemically identical, differing only in spelling.
Is one form of spelling more correct than the other?
Neither spelling is "more correct"; the choice depends on regional and institutional preferences.
What dietary sources are rich in heme/haem?
Heme iron, found in animal products, is more readily absorbed than non-heme iron from plant sources.
What is the importance of heme/haem in cellular respiration?
Heme is vital for cellular respiration as it helps transport oxygen necessary for energy production.
Are there environmental impacts associated with synthetic heme/haem production?
Synthetic heme production can have environmental impacts, depending on the industrial processes used.
How is heme/haem produced in the body?
Heme is synthesized through a multi-step process in the liver and bone marrow.
What role does heme/haem play in plant life?
Plants do not contain heme, but they have similar compounds, such as chlorophyll, for oxygen-related processes.
What diseases are associated with heme/haem?
Disorders such as porphyria and anemia can involve problems with heme production or function.
How is synthetic heme/haem used in medicine?
Synthetic heme is used in treatments for anemia and as a dietary supplement.
Is heme/haem visible to the naked eye?
Heme is not individually visible; it is visible due to its incorporation in hemoglobin, which colors blood red.
What advancements are being made in heme/haem research?
Advances include developing synthetic heme for vegetarian diets and studying its role in disease mechanisms.
Can heme/haem levels be too high or too low?
Yes, abnormal heme levels can indicate various health issues, including liver problems and blood disorders.
Share Your Discovery
Previous Comparison
Marten vs. Sable
Next Comparison
Subscribe vs. PrescribeAuthor Spotlight
Written by
Fiza RafiqueFiza Rafique is a skilled content writer at AskDifference.com, where she meticulously refines and enhances written pieces. Drawing from her vast editorial expertise, Fiza ensures clarity, accuracy, and precision in every article. Passionate about language, she continually seeks to elevate the quality of content for readers worldwide.
Co-written by
Urooj ArifUrooj is a skilled content writer at Ask Difference, known for her exceptional ability to simplify complex topics into engaging and informative content. With a passion for research and a flair for clear, concise writing, she consistently delivers articles that resonate with our diverse audience.
