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Biological roles of the elements. A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms.It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of cell biology, Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology ...
Mineral (nutrient) Carbonic anhydrase, an enzyme that requires zinc (gray sphere near the center of this image), is essential for exhalation of carbon dioxide. In the context of nutrition, a mineral is a chemical element. Some "minerals" are essential for life, but most are not. [1] [2] [3] Minerals are one of the four groups of essential ...
The main elements that comprise the human body (including water) can be summarized as CHNOPS . About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
G ὑπέρ Βορέᾱ ( hupér Boréā) from the Arctic region ( Hyperborea) glaucous gull, Larus hyperboreus; tundra fleabane, Erigeron hyperboreus. tangle or cuvie, Laminaria hyperborea; estuary beggarsticks, Bidens hyperborea. boreal bur-reed, Sparganium hyperboreum; boreal haircap moss, Polytrichum hyperboreum.
It is the least dense of all elements that are solids at room temperature; the next lightest solid element (potassium, at 0.862 g/cm 3) is more than 60% denser. Apart from helium and hydrogen, as a solid it is less dense than any other element as a liquid, being only two-thirds as dense as liquid nitrogen (0.808 g/cm 3). [15]
The periodic table is a tabular arrangement of the chemical elements, organized by their atomic number, electron configuration, and chemical properties. It is a useful tool for understanding the patterns and trends of the elements and their interactions. Learn more about the history, structure, and significance of the periodic table on Wikipedia.
A protein is a polyamide. Secondary structure: regularly repeating local structures stabilized by hydrogen bonds. The most common examples are the α-helix, β-sheet and turns. Because secondary structures are local, many regions of different secondary structure can be present in the same protein molecule.