Lecithin is (organic chemistry) the principal phospholipid in animals; it is particularly abundant in egg yolks, and is extracted commercially from soy. It is also a major constituent of cell membranes, and is commonly used as a food additive (as an emulsifier). While cephalin is (biochemistry) a phospholipid found particularly in the cells of nervous tissue; it is also the primary phospholipid in bacteria.
The principal function of thyroxine is to stimulate the consumption of oxygen and thus the metabolism of all cells and tissues.
Thyroxine is termed T4. It travels through the blood to the target cells and becomes converted to triiodothyronine or T3.
T3 is the active form of thyroxine. T3 enters the target cell's nucleus binding to genes responsible or involved in the metabolism of sugar in the body. T3 stimulates these genes and in so doing metabolism (conversion of oxygen and calories to energy) is carried out by the cell, which also results in generation of body heat.
"How does carbon enter water?" : Carbon<span> dioxide from the atmosphere dissolves in the surface waters of the ocean. Some of the </span>carbon<span> dioxide stays as dissolved gas, but much of it gets turned into other things. Photosynthesis by tiny marine plants (phytoplankton) in the sunlit surface waters turns the </span>carbon<span> into organic matter.
"How does aquatic plants get carbon" : </span><span>The only difference between photosynthesis in </span>aquatic<span> and land </span>plants<span> is where in their environments they </span>get<span> these nutrients. Land </span>plants get<span> water from the ground through their extensive root system, </span>carbon<span> dioxide from the air through their stomata (tiny holes in a </span>plant's<span> leaves), and energy from the sun.</span>
