Question

what are pyrenoids? and they are made up of?

Answer 1

any of several transparent structures found in the chloroplast of certain algaeetc.; they are responsible for the fixation of carbon dioxideand the formation of starch

Answer 2

Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae,[1] and in a single group of land plants, the hornworts.[2] Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2 rich environment around the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria.