Marine Algae & Hydrocolloids — NEET Biology
✅ Asked in NEET 2022Algae are useful to man in a variety of ways. At least a half of the total carbon dioxide fixation on earth is carried out by algae through photosynthesis. Being photosynthetic, they increase the level of dissolved oxygen in their immediate environment. They are of paramount importance as primary producers of energy-rich compounds which form the basis of the food cycles of all aquatic animals. Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine algae used as food. Certain marine brown and red algae produce large amounts of hydrocolloids (water holding substances), e.g., algin (brown algae) and carrageen (red algae) which are used commercially. Agar, one of the commercial products obtained from Gelidium and Gracilaria are used to grow microbes and in preparations of ice-creams and jellies. Chlorella, a unicellular alga rich in proteins, is used as food supplement even by space travellers. The algae are divided into three main classes: Chlorophyceae, Phaeophyceae and Rhodophyceae.
NTA tests your knowledge of hydrocolloids—water-holding substances produced by marine brown and red algae. Algin (from brown algae) and carrageen (from red algae) are commercially important hydrocolloids with industrial applications. Students often confuse which algae produce which hydrocolloid or mix up hydrocolloids with agar. Remember: algin = brown algae, carrageen = red algae, and agar comes from red algae (Gelidium and Gracilaria) but is technically a carbohydrate polymer, not a traditional hydrocolloid. This concept tests your understanding of algal classification and their economic importance.
Hydrocolloid carrageen is obtained from: [NEET 2022 Phase 1]
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