zwierzęta: Glucose

Evidence: 100 • authority: 72

Glucose is a sugar with the molecular formula C6H12O6. It is the most abundant monosaccharide, a subcategory of carbohydrates. It is made from water and carbon dioxide during photosynthesis by plants and most algae. It is used by plants to make cellulose, the most abundant carbohydrate in the world, for use in cell walls, and by all living organisms to make adenosine triphosphate (ATP), which is used by the cell as energy. Glucose is often abbreviated as Glc. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as amylose and amylopectin, and in animals as glycogen. Glucose circulates in the bl…

Evidence: 64 • authority: 72

Evidence: 64 • authority: 72

Evidence: 54 • authority: 72

Evidence: 45 • authority: 72

In chemistry, a substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. Chemical substances can exist in several different physical states or phases (e.g. solids, liquids, gases, or plasma) without changing their chemical composition. Substances transition between these phases of matter in response to changes in temperature or pre…

Evidence: 45 • authority: 92

Three Water Molecules Mediate Ring Opening of d‑Glucose in Aqueous Solutions.. The mechanism of d-glucose ring opening has long been debated, particularly with regard to whether proton transfer occurs through a concerted or stepwise pathway and how many water molecules participate in the process. Here, we employ ab initio molecular dynamics combined with metadynamics to investigate both possibilities. Our results identify a lower-energy concerted pathway in which proton transfer is mediated by a three-water hydrogen-bond network. Indeed, the transition state features a cyclic hydrogen-bonded water bridge linking OH 1 and O 5 . This bridge promotes proton transfer from OH 1 to O 5 , thereby…