Grana function?

It seems like you may be referring to the term "grana" in biology, specifically in relation to plant cells. Grana are stacks of thylakoid discs found in the chloroplasts of plant cells. They are the sites of photosynthesis, where light energy is converted into chemical energy in the form of glucose. The grana function to increase the surface area available for photosynthetic reactions to occur, allowing plants to produce energy efficiently.

What is Authority