Is the symbol S reactant

In facilitated diffusion what are the special channels that help substances cross the cell membrane made of? What is an iron nail reactive with when forming rust? What is following is not an assumption of kinetic theory of gases? What minerals are in stainless steel utensils? Why are there more stomata on the lower side of a leaf? The core is probably solidified? What are the 4 main minerals Like gems and precious stones? What did the study of commercial geography started? What does the ventricular system produce? Nearest city to equator? What organ in the human body uses 40 percent of the oxygen in your blood? How does cycling of matter occur in earth's mantle? What term describes a polypeptide that is folded in 3-d structure and serve a purpose in living organisms? What occurs outside the Calvin cycle? How is standard Na2S2O3 solution carried out? What are the two types of crystallization? What may store water needed chemicals wastes pigments in a plant cell? What is the 4 planet? What enzyme is responsible for aerobic respiration? What companies have heat resistant glass experiment containers?