EVERYDAY SCIENCE

Detailed explanation-1: -The Fucus is marine brown alga and mannitol is the stored food in these organisms. Gracilaria and Porphyra are red algae and food reserves are stored outside of the chloroplasts as Floridean starch. Chara is green algae and most of the members have one or more storage bodies called pyrenoids located in the chloroplast.

Detailed explanation-2: -Mannitol is a form of complex carbohydrates stored as food in some definite algae. The members of Phaeophyceae, also known as brown algae, stored food as mannitol. Mannitol represents the major end product in theses algae and is the main form of carbon storage. It is formed by reduction of fructose-6-phosphate.

Detailed explanation-3: -Gracilaria belongs to Rhodophyceae (Red algae) and stores reserve food in the form of floridean starch.

Detailed explanation-4: -The members of Phaeophyceae (brown algae) store mannitol as a reserve food material.

Detailed explanation-5: -Because of their unique evolutionary history and of their habitat, brown algae feature several peculiarities in their metabolism. One of these is the mannitol cycle, which plays a central role in their physiology, as mannitol acts as carbon storage, osmoprotectant, and antioxidant.