hemoglobin

play
noun he·mo·glo·bin \ ˈhē-mə-ˌglō-bən \

Definition of hemoglobin

1 :an iron-containing respiratory pigment of vertebrate red blood cells that consists of a globin composed of four subunits each of which is linked to a heme molecule, that functions in oxygen transport to the tissues after conversion to oxygenated form in the gills or lungs, and that assists in carbon dioxide transport back to the gills or lungs after surrender of its oxygen
2 :any of numerous iron-containing respiratory pigments of various organisms (such as invertebrates and yeasts)

Recent Examples of hemoglobin from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hemoglobin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

When filled with oxygen, the hemoglobin in your blood is bright red; returning to the lungs without its oxygen, it loses its brightness and becomes somewhat bluish. Hemoglobin levels can change from day to day, and may be affected by such factors as a lack of iron in the diet, a recent loss of blood, and being pregnant. When you give blood, a nurse first pricks your finger to test your hemoglobin level; a low hemoglobin count indicates anemia and may mean that you shouldn't give blood that day. Mild anemia is generally of little importance, but some types can be very serious.

Origin and Etymology of hemoglobin

International Scientific Vocabulary, short for earlier hematoglobulin

Other Biochemistry Terms


HEMOGLOBIN Defined for English Language Learners

hemoglobin

play
noun

Definition of hemoglobin for English Language Learners

  • : the part of blood that contains iron, carries oxygen through the body, and gives blood its red color


HEMOGLOBIN Defined for Kids

hemoglobin

play
noun he·mo·glo·bin \ ˈhē-mə-ˌglō-bən \

Definition of hemoglobin for Students

:a protein of red blood cells that contains iron and carries oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs

Medical Dictionary

hemoglobin

noun he·mo·glo·bin
variants: or chiefly British haemoglobin play \ˈhē-mə-ˌglō-bən\

medical Definition of hemoglobin

1 :an iron-containing respiratory pigment of vertebrate red blood cells that functions primarily in the transport of oxygen from the lungs to the tissues of the body, that consists of four polypeptide chains of which two are of the type designated alpha and two are of one of the types designated beta, gamma, or delta and each of which is linked to a heme molecule, that combines loosely and reversibly with oxygen in the lungs or gills to form oxyhemoglobin and with carbon dioxide in the tissues to form carbaminohemoglobin, that in humans is present normally in blood to the extent of 14 to 16 grams in 100 milliliters expressed sometimes on a scale of 0 to 100 with an average normal value (as 15 grams) taken as 100, and that is determined in blood either colorimetrically or by quantitative estimation of the iron present — see fetal hemoglobin, hemoglobin a — compare carboxyhemoglobin, methemoglobin
2 :any of numerous iron-containing respiratory pigments of various organisms (as invertebrates and yeasts)

hemoglobinic

or chiefly British haemoglobinic play \ˌhē-mə-glō-ˈbin-ik\ adjective

hemoglobinous

or chiefly British haemoglobinous play \-ˈglō-bə-nəs\ adjective


Seen and Heard

What made you want to look up hemoglobin? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

to curse or denounce

Get Word of the Day daily email!

Test Your Vocabulary

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

  • young-plant-shoots
  • Which of the following is a new sense of the word bunny?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Citation

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!