granum

[ grey-nuhm ]

noun

, plural gra·na [grey, -n, uh].

1. (in prescriptions) a grain.
2. Botany. one of the structural units of a chloroplast in vascular plants, consisting of layers of thylakoids.

granum

/ grā′nəm /

, Plural grana grā′nə

1. A stacked membranous structure within the chloroplasts of plants and green algae that contains the chlorophyll and is the site of the light reactions of photosynthesis. The saclike membranes that make up grana are known as thylakoids.
2. See more at chloroplast

Word History and Origins

Origin of granum¹

From Latin

Example Sentences

Imperial Granum is an example of this group, and there are several others with similar compositions.

From Project Gutenberg

The Spanish name grana, confounded with granum, may have given rise to this contest.

From Project Gutenberg