All articles starting with P

Phosphorus anode

A phosphorus anode is a battery negative electrode of red or black phosphorus that stores lithium or sodium ions by alloying, offering 2,596 mAh g⁻¹ theoretical capacity.

The phosphorus cycle is the biogeochemical cycle that moves phosphorus among rocks, soils, water, and organisms through weathering, river transport, and sediment burial, with no significant gaseous phase.

Oct 22, 2026

Phosphorus donor qubit in silicon

A phosphorus donor qubit in silicon is a quantum bit formed from a single phosphorus-31 atom in silicon, encoding information in its electron or nuclear spin.

Phosphorus limitation

Phosphorus limitation is the control of biological production by phosphorus supply, the principle that phosphorus, not nitrogen or carbon, governs algal blooms and eutrophication in lakes.

Phosphorus loading

Phosphorus loading is the quantity of phosphorus delivered to a water body per unit time, either from the watershed and atmosphere or released from lake sediments.

Oct 22, 2026

Phosphorus nitride

Phosphorus nitride refers to binary compounds of phosphorus and nitrogen, chiefly the diatomic PN molecule, first detected in interstellar space, and solid phosphorus(V) nitride, P3N5, first obtained in 1862.

Phosphorus pentachloride

Phosphorus pentachloride (PCl₅) is a pale-yellow, fuming solid of phosphorus and chlorine used as a chlorinating agent, existing as trigonal bipyramidal molecules in gas and an ionic lattice in the solid.

Phosphorus pentoxide

Phosphorus pentoxide, also known as phosphoric anhydride, is a white, hygroscopic oxide of phosphorus with the molecular formula P4O10, made by burning phosphorus in dry air and used as a powerful drying and dehydrating agent.

Phosphorus sorption

Phosphorus sorption is the attachment of dissolved phosphate to sediment and soil particle surfaces, a process that buffers phosphorus concentrations in streams, lakes, and estuaries and drives eutrophication.

Phosphorus trichloride

Phosphorus trichloride, also known as PCl3 or trichlorophosphine, is a colorless fuming liquid used industrially as a reactive chlorinating agent that reacts violently with water.

Phosphorus-32

Phosphorus-32 is a radioactive isotope of phosphorus with a half-life of about 14.3 days that decays by beta emission, used to label DNA and proteins in research.

Phosphoryl chloride

Phosphoryl chloride, also called phosphorus oxychloride, is a colorless fuming liquid with the formula POCl₃, used as a chlorinating agent and to dope silicon solar cells.

Phosphorylated adapter RNA export protein

PHAX (phosphorylated adapter RNA export protein, gene PHAX/RNUXA, UniProt Q9H814) is a 394-amino-acid metazoan phosphoprotein adapter for CRM1/XPO1-mediated U snRNA nuclear export, activated by nuclear CK2 phosphorylation and inactivated by cytoplasmic PP2A dephosphorylation.

Phosphorylation

Phosphorylation is the addition of a phosphate group to a molecule such as a sugar or protein, the reversible kinase-phosphatase switch discovered by Fischer and Krebs, 1992 Nobel Prize, central to cell signaling.

Phosphorylcholine

Phosphorylcholine, also called phosphocholine, is a small zwitterionic molecule that serves as the polar head group of phosphatidylcholine and an intermediate in its biosynthesis via the Kennedy pathway.

Phosphoserine aminotransferase

Phosphoserine aminotransferase (PSAT), encoded by the PSAT1 gene, is the middle enzyme of the three-step human L-serine biosynthesis pathway; inherited defects cause a treatable neurometabolic disease.

Phosphoserine phosphatase

Phosphoserine phosphatase (PSP, EC 3.1.3.3, SerB) is the Mg2+-dependent HAD-superfamily enzyme catalyzing the final step of L-serine biosynthesis, forming a phospho-aspartate intermediate; deficiency causes L-serine deficiency disorders.

Phosphothreonine

Phosphothreonine, or O-phospho-L-threonine, is the phosphorylated derivative of the amino acid L-threonine, first isolated from bovine casein in 1953 and the second most abundant protein phosphorylation.

Phosphotransferase system, IIA component fructose subfamily

Fructose-subfamily IIA component (IIA^Fru) of the bacterial PTS, a cytoplasmic histidine phospho-carrier feeding fructose transport; tetrameric in S. mutans, encoded by fruB/fruA operons, most widely distributed sugar-specific Enzyme II.

Phosphotransferase system, mannitol-specific enzyme IIC

Mannitol-specific enzyme IIC (IICmtl, MtlA) is the membrane domain of the E. coli PTS mannitol transporter: a homodimer with one ~100 nM mannitol-binding site, phosphorylating mannitol to mannitol-1-phosphate.

Phosphotransferase system, sugar-specific permease EIIA type 1

Phosphotransferase system, sugar-specific permease EIIA type 1 (InterPro IPR001127, Pfam PF00358 PTS_EIIA_1): a bacterial protein domain of enzyme IIA in the glucose-superfamily PTS permeases, carrying phosphoryl groups from HPr to EIIB and regulating carbon metabolism in enteric bacteria.

Phosphotriesterase

Phosphotriesterase (PTE, organophosphate hydrolase, EC 3.1.8.1) is a zinc-dependent bacterial TIM-barrel enzyme from Brevundimonas diminuta that hydrolyzes organophosphate insecticides and nerve agents; engineered variants detoxify VX and sarin.

Phosphotungstic acid

Phosphotungstic acid, also called 12-tungstophosphoric acid, is a heteropoly acid (H3PW12O40) used as a strong acid catalyst and as a negative stain in electron microscopy.

Phosphotyrosine protein phosphatase domain

Phosphotyrosine protein phosphatase domain (PTP domain): conserved C(X)5R-motif catalytic domain of protein tyrosine phosphatases, over 100 human members, cysteine-based two-step dephosphorylation mechanism, prototype PTP1B.

Phossy jaw

Phossy jaw (phosphorus necrosis of the jaw) was an occupational osteonecrosis of match-factory workers exposed to white phosphorus fumes; about 11% of the exposed developed it, it killed roughly 20%, and it ended after the 1906 Berne Convention.

Photek

Photek is the alias of British producer Rupert Parkes of St Albans, a pioneer of intelligent drum & bass and jungle. Known for aliases like Studio Pressure and Aquarius, his 1997 debut Modus Operandi on Virgin's Science imprint defined precision drum programming.