EVERYDAY SCIENCE

Detailed explanation-1: -Mannitol and laminarin are considered as reserve food material in many brown algae species. These are complex carbohydrates. Mannitol is a sugar alcohol form of mannose, while laminarin is a linear polysaccharide of mannitol-containing -1, 3-linked glucose.

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: -In Phaeophyceae, laminarin is the stored food and major pigments are chlorophyll a and b.

Detailed explanation-4: -Solution: Ectocarpus is a brown alga belongs to the class Phaeophyceae. Members of this class have mannitol and laminarin as stored 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.