All articles starting with P

Phosphate glass

Phosphate glass is a glass in which phosphorus pentoxide, not silica, forms the network, allowing compositions used in high-power lasers, hermetic seals, nuclear waste hosts, and resorbable biomedical implants.

Phosphate minerals

Phosphate minerals are naturally occurring crystalline compounds built around the phosphate anion, forming a major mineral class dominated by apatite and supplying nearly all phosphorus used in fertilizers.

Oct 22, 2026

Phosphate mining in Nauru

Phosphate mining in Nauru is the extraction of rock phosphate from the Pacific island of Nauru, an industry begun in 1906 that stripped roughly 80 percent of the island's land.

Phosphate propanoyltransferase

Phosphate propanoyltransferase (PduL) is a bacterial phosphotransacylase encoded by pduL that converts propanoyl-CoA to propanoyl-phosphate inside Pdu bacterial microcompartments during 1,2-propanediol degradation, recycling CoA and enabling ATP production; it is structurally unrelated to Pta.

Phosphate regulon sensor protein PhoR, N-terminal domain

PhoR N-terminal domain: membrane-anchoring and PAS signal-sensing region of the PhoR histidine kinase sensor of the bacterial phosphate regulon; E. coli PhoR is 431 residues, 49,666 Da, partner to PhoB.

Phosphate rock

Phosphate rock is a natural rock containing apatite, a calcium phosphate mineral mined as the primary source of phosphorus for phosphate fertilizers vital to agriculture.

Phosphate transporter

Phosphate transporter: membrane protein moving inorganic phosphate across membranes. Plant PHT1-PHT5 families (plasma membrane to vacuole) and mammalian SLC20/SLC34 Na+-Pi cotransporters; regulated by PTH, FGF23, vitamin D.

Phosphate-buffered saline

Phosphate-buffered saline (PBS) is a pH 7.4 salt solution of NaCl, KCl, and phosphate salts used to wash cells and tissue and dilute reagents; standard 1X mix is 137 mM NaCl, 2.7 mM KCl, 10 mM Na2HPO4, 1.8 mM KH2PO4.

Phosphatidate phosphatase

Phosphatidate phosphatase, or PAP, is an enzyme that converts phosphatidic acid to diacylglycerol, a precursor of triglycerides and membrane phospholipids; in mammals the lipins carry this activity.

Phosphatidic acid

Phosphatidic acid (PA, PtdOH, 1,2-diacyl-sn-glycerol-3-phosphate) is the simplest glycerophospholipid: precursor of all other phospholipids, a second messenger, pH-sensing anionic lipid, and mTORC1 activator.

Phosphatidyl-N-methylethanolamine/Phosphatidylethanolamine N-methyltransferase

PEMT (phosphatidylethanolamine N-methyltransferase) is an ER and mitochondria-associated membrane enzyme that methylates phosphatidylethanolamine to phosphatidylcholine using SAM, the only endogenous choline source in mammals, mainly hepatic, linked to NAFLD, obesity, and HCV steatosis.

Phosphatidylcholine

Phosphatidylcholine (PC, lecithin) is the most abundant mammalian membrane phospholipid, about 50% of cellular phospholipid, made via the Kennedy CDP-choline and PEMT pathways, essential for VLDL secretion, bile micelles, and lung surfactant.

Phosphatidylethanolamine

Phosphatidylethanolamine (PE), a zwitterionic cone-shaped glycerophospholipid, is the second most abundant cellular phospholipid (15-25% of lipids), made via the ER Kennedy pathway and mitochondrial PS decarboxylation, and essential for membrane fusion, mitochondria, and autophagy.

Phosphatidylethanolamine transferase Mcr-1

MCR-1, product of the mcr-1 gene, is a plasmid-encoded Zn2+-dependent phosphoethanolamine transferase that modifies lipid A, giving Gram-negative bacteria transferable resistance to the last-resort antibiotic colistin; discovered in China in 2015.

Phosphatidylethanolamine-binding protein

Phosphatidylethanolamine-binding protein (PEBP1, RKIP), a conserved 23 kDa cytosolic protein, inhibits Raf-MEK-ERK and NF-κB signaling, yields the peptide HCNP, and acts as a cancer metastasis suppressor.

Phosphatidylglycerol

Phosphatidylglycerol (PG) is a negatively charged glycerophospholipid found across all domains of life, a major component of bacterial membranes, chloroplast thylakoid membranes, and lung surfactant, where its absence signals fetal respiratory distress syndrome.

Phosphatidylinositol 3,4,5-trisphosphate

Phosphatidylinositol 3,4,5-trisphosphate (PIP3, also written PtdIns(3,4,5)P3) is a minor membrane phospholipid that acts as a second messenger: PI3K makes it, PTEN removes it, and it recruits proteins like AKT to control cell growth, survival, and metabolism.

Phosphatidylinositol 4-kinase, Pik1, helix hairpin, fungi

Pik1 is the type III phosphatidylinositol 4-kinase of budding yeast and the homolog of mammalian PI4KIIIβ, producing PtdIns4P at the Golgi; its Frq1-regulated two-helix binding segment is essential for fungal secretion and growth.

Phosphatidylinositol 4,5-bisphosphate

Phosphatidylinositol 4,5-bisphosphate (PIP₂) is a signaling phospholipid concentrated on the inner leaflet of the plasma membrane, where it regulates ion channels and the actin cytoskeleton.

Oct 20, 2026

Phosphatidylinositol transfer protein

Phosphatidylinositol transfer proteins (PITPs, PITPα/β, RdgB proteins) are conserved eukaryotic lipid exchangers that bind and transfer PI or PC between membranes, sustaining phosphoinositide signaling, PLC signalling, and Golgi trafficking.

Phosphatidylinositol-4-phosphate 4/5-kinase, core

Phosphatidylinositol-4-phosphate 4/5-kinase core (PIPKc, IPR002498) is the conserved catalytic kinase domain of PIPK lipid kinases (PIP5K, PIP4K, PIKfyve), defined by a KDD catalytic site, specificity loop, and monophosphate binding site.

Phosphatidylserine

Phosphatidylserine (PS), an anionic aminophospholipid, is the most abundant negatively charged phospholipid in eukaryotic membranes, kept in the inner plasma-membrane leaflet by flippases; its surface exposure signals apoptosis and blood clotting.

Phosphene

A phosphene is the perception of light without light entering the eye, caused by pressure, electrical, or magnetic stimulation of the retina or visual cortex.

Phosphine

Phosphine, also called hydrogen phosphide, is a colorless, flammable, highly toxic gas with a garlic-like odor, used mainly to fumigate stored grain and as a dopant in semiconductor manufacturing.

Oct 22, 2026

Phosphine in the atmosphere of Venus

Phosphine in the atmosphere of Venus is a claimed 2020 detection of the gas phosphine in Venus's clouds, led by Jane Greaves, which remains debated.

Phosphine oxide

A phosphine oxide is an organophosphorus compound of the structure R₃P=O, whose strong phosphorus–oxygen bond makes it a stable by-product of Wittig, Mitsunobu, Appel, and Staudinger reactions.

Oct 22, 2026

Phosphinidene

A phosphinidene is a monomeric phosphorus(I) compound of formula R−P, the phosphorus analog of a nitrene or carbene, usually stabilized by a metal, a carbene, or another donor.

Phosphite

Phosphite is the divalent inorganic anion HPO₃²⁻, obtained from phosphorous acid; its salts and esters act as systemic fungicides against oomycetes but supply no usable phosphorus to plants.

Phospho-L-tyrosine

Phospho-L-tyrosine, also known as O-phospho-L-tyrosine, is a non-proteinogenic amino acid formed by phosphorylating L-tyrosine; as the phosphotyrosine residue it is a central eukaryotic signaling mark.