granum definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
noun pl. grana
any of the stacks of thylakoids in a chloroplast
granum definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
noun pl. gra·na
A stacked membranous structure within a chloroplast that contains the chlorophyll and is the site of the light reactions of photosynthesis.
Origin: Latin grānum, seed; see grain.
granum - Science Definition
Plural grana grana
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. See more at chloroplast.