1. Red Algae

2. What is Red Algae? • It is the largest phyla of algae • Its scientific name is rhodophyta • It is made up of eukaryotic cells without flagella and centrioles, unstacked thylakoids, and no chloroplast ER. • Unstacked thylakoids in plastids

3. Some red algae have very little phycoerythrin, and may appear green or bluish. Pigment • Red algae is red because of the presence of red phycoerythrin. It is often the dominant pigment. • It reflects red light and absorbs blue light.

4. Depth • Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at greater depths than most other algae.

5. Food • In Asia, red algae is an important source of food. • It has a high vitamin and protein content. • It is easy to cultivate, which began in Japan more than 300 years ago. • Red algae can be dried up to make nori

6. Products • One type of red algae, coralline, secretes a calcium carbonate skeleton in the same way that corals do. They have contributed to reef structure even more so than corals. • A closer look at coralline algae: http://www.youtube.com/watch?v=ITW023ZU7Zo&feature=related

7. Review Questions • Why is red algae red? • What is the significance of coralline red algae? • What does coralline red algae secrete? • Red algae reflects what and absorbs what? • Why is red algae able to grow at greater depths than other algae? • What about red algae makes it a valuable food source? • Answers on next slide...

8. Review Question Answers • Because of the presence of red phycoerythrin • It contributes a lot to reef structure • Calcium carbonate • Red algae reflects red light and absorbs blue light. • Because blue light penetrates water to a greater depth than light of longer wavelengths • It has a high vitamin and protein content and also easy to cultivate