Hydrogen fuel cells power the shuttle's electrical systems, producing a clean byproduct-pure water, which the crew drinks. A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge.
Chlorophyll b is a form of chlorophyll. Chlorophyll b helps in photosynthesis by absorbing light energy. It is more soluble than chlorophyll a in polar solvents because of its carbonyl group. Its color is yellow, and it primarily absorbs blue light.n land plants, the light-harvesting antennae around photosystem II contain the majority of chlorophyll b. Hence, in shade-adapted chloroplasts, which have an increased ratio of photosystem II to photosystem I, there is a lower ratio of chlorophyll a to chlorophyll b.
All plants, algae, and cyanobacteria which photosynthesize contain chlorophyll a. A second kind of chlorophyll is chlorophyll b, which occurs only in green algae and in the plants.A third form of chlorophyll which is common is (not surprisingly) called chlorophyll c, and is found only in the photosynthetic members of the Chromista as well as the dinoflagellates.ore important than their reflection of light is the ability of pigments to absorb certain wavelengths. Because they interact with light to absorb only certain wavelengths, pigments are useful to plants and other autotrophs --organisms which make their own food using photosynthesis.