methaemoglobin: meaning, definition, pronunciation and examples
Very Low (C2+)Specialised Technical / Medical
Quick answer
What does “methaemoglobin” mean?
A form of haemoglobin in which the iron is oxidised (Fe³⁺), rendering it incapable of binding oxygen.
Audio
Pronunciation
Definition
Meaning and Definition
A form of haemoglobin in which the iron is oxidised (Fe³⁺), rendering it incapable of binding oxygen.
A pathological, non-functional derivative of haemoglobin present in the blood, often as a result of certain drugs, chemicals, or genetic disorders, leading to impaired oxygen transport and potential cyanosis.
Dialectal Variation
British vs American Usage
Differences
Spelling: British English prefers 'methaemoglobin' (ae), while American English uses 'methemoglobin' (e).
Connotations
Identical in both varieties; purely technical with negative clinical connotations.
Frequency
Extremely rare in non-specialist contexts in both varieties. The American spelling 'methemoglobin' is the global standard in most scientific literature.
Grammar
How to Use “methaemoglobin” in a Sentence
The [noun] caused an increase in methaemoglobin.Methaemoglobin [verb] oxygen transport.A diagnosis of methaemoglobinaemia was confirmed.Vocabulary
Collocations
Examples
Examples of “methaemoglobin” in a Sentence
adjective
British English
- The methaemoglobin fraction was alarmingly high.
American English
- The methemoglobin level required immediate treatment.
Usage
Meaning in Context
Business
Not used.
Academic
Core term in biochemistry, pharmacology, and clinical medicine.
Everyday
Virtually never used.
Technical
Essential term in toxicology, haematology, and emergency medicine; used in lab reports and diagnosis.
Vocabulary
Synonyms of “methaemoglobin”
Strong
Neutral
Weak
Vocabulary
Antonyms of “methaemoglobin”
Watch out
Common Mistakes When Using “methaemoglobin”
- Misspelling: 'methaemoglogin', 'methaemaglobin'.
- Using it as a verb, e.g., 'The blood methaemoglobined.'
- Confusing it with carboxyhaemoglobin (bound to carbon monoxide).
FAQ
Frequently Asked Questions
No. Methaemoglobin has oxidised iron (Fe³⁺) and cannot bind oxygen. Carbon monoxide poisoning involves carboxyhaemoglobin, where haemoglobin binds tightly to CO instead of O₂.
The standard treatment is intravenous methylene blue, which acts as a reducing agent to convert methaemoglobin back to functional haemoglobin.
Yes, normally 1-2% of total haemoglobin is in the methaemoglobin form due to spontaneous oxidation; enzymatic systems (like cytochrome b5 reductase) constantly reduce it back.
British English retains the 'ae' digraph: 'methaemoglobin'. American English simplifies it to 'e': 'methemoglobin'.
A form of haemoglobin in which the iron is oxidised (Fe³⁺), rendering it incapable of binding oxygen.
Methaemoglobin is usually specialised technical / medical in register.
Methaemoglobin: in British English it is pronounced /mɛtˌhiːməˈɡləʊbɪn/, and in American English it is pronounced /mɛtˌhiməˈɡloʊbɪn/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: METHod ruined the HAEMOGLOBIN. The iron got oxidised (like rust) and now it can't carry oxygen.
Conceptual Metaphor
A corrupted file in the oxygen-delivery system.
Practice
Quiz
What is the primary functional consequence of methaemoglobin formation?