Can photosynthesis occur when the stomata are closed?

Question

For one of the disadvantages of closed stomata to a plant when water is in short supply - can i say that because there isn't gas exchange, that photosynthesis would stop?

or would that mean that the plant would die without photosynthesis?

in that case is photosynthesis slowed down at all? it doesn't occur at the same rate as it would in an environment with water..?!?!

thanks for all your help!

Answer 1

Yes photosynthesis can occur when stomata are closed.   During CAM Photosynthesis, after the plant family in which it was first found (Crassulaceae) and because the CO2 is stored in the form of an acid before use in photosynthesis.

Stomata open at night (when evaporation rates are usually lower) and are usually closed during the day. The CO2 is converted to an acid and stored during the night. During the day, the acid is broken down and the CO2 is released to RUBISCO for photosynthesis.  Plants using CAM pathways live in arid climates and must conserve water.