heme

Definitions

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.

countable, uncountable

Equivalents

Examples

“The binding of oxygen to the iron⟳ molecule causes the hemoglobin molecule to undergo⟳ conformational changes that affect⟳ the binding of oxygen to other heme sites.”

“Impossible's breakthrough was in discovering that meat's essence comes from heme—the iron-rich molecule in blood that carries oxygen and is responsible for the deep-red color.”

CEFR level