Question

1) What is the pigment that is present in Eurkaryotes GENUINELY (without plastid endosymbiosis, and even in animals like us), which was used for photosynthesis in some relatives of Eukaryotes?
2) What is the name for those PHOTOYNTHETIC relatives of Eukaryotes? Genus or informal name that is specific enough.

Answer 1

1.Carotenoids are pigments that absorb blue and green light and reflect yellow, orange, or red. Phycocyanins absorb green and yellow light and reflect blue or purple. These accessory pigments absorb light energy and transfer it to chlorophyll. They are found in plant cells and algae.The thylakoid membrane contains a number of integral membrane proteins to which are bound several important prosthetic groups and light-absorbing pigments, most notably chlorophyll. Carbohydrate synthesis occurs in the stroma, the soluble phase between the thylakoid membrane and the inner membrane.Chlorophylla-a is the primary pigment for photosynthesis in plants, but the range of light absorption is extended by chlorophyll-b, beta-carotene and other accessory pigments. The nucleus is particularly important among eukaryotic organelles because it is the location of a cell's DNA. Two other critical organelles are mitochondria and chloroplasts, which play important roles in energy conversion and are thought to have their evolutionary origins as simple single-celled organisms.There are several kinds of chlorophyll, the most important being chlorophyll "a". This is the molecule which makes photosynthesis possible, by passing its energized electrons on to molecules which will manufacture sugars. All plants, algae, and cyanobacteria which photosynthesize contain chlorophyll "a".Chlorophyll a is the core pigment that absorbs sunlight for light dependent photosynthesis. Accessory pigments such as cholorphyll b, carotenoids, xanthophylls and anthocyanins lend a hand to chlorophyll a molecules by absorbing a broader spectrum of light waves.The importance of pigment in photosynthesis is that it helps absorb the energy from light. During photosynthesis these high-energy electrons transfer their energy to other molecules, or these electrons themselves get transferred to other molecules. Hence, they release the energy they had captured from light.

2.The appearance of photosynthetic eukaryotes (algae and plants) dramatically altered the ecosystem, making possible all vertebrate life on land, including humans.Algae like plants, these organisms are eukaryotic and their cells contain organelles (nucleus, mitochondria, chloroplasts, endoplasmic reiticulum, golgi bodies etc.). Photosynthesis in these organisms takes place in their chloroplasts just as in plants.Eukaryotes like plants and green algae contain membrane bounded organelles which aid them to perform photosynthesis. The process of photosynthesis is basically divided into two steps i.e Light reactions and dark reactions (known as Calvin cycle or C3 pathway). In eukaryotic cells that can do photosynthesis, it takes place in organelles called chloroplasts, or more generically, plastids