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An IP3 receptor is an intracellular ligand-gated ion channel, rather than the extracellular signal's cell-surface receptor. Its opening is regulated by both IP3 and cytosolic calcium: IP3 binding is not a command that fixes one constant release rate. Mammalian IP3 receptors have three subtypes, with possible mixed assemblies and splice variants; these need not have identical regulation or cellular roles. The 2010 authored account distinguishes established channel behavior from then-unresolved structural explanations.^[ref]

Phospholipase C catalyzes hydrolysis of membrane PIP2, producing soluble IP3 and membrane-associated diacylglycerol. This consumes a phospholipid substrate, rather than manufacturing calcium. G protein-regulated and receptor tyrosine kinase-regulated forms of PLC provide different routes to this reaction.^[ref]

Two conjugate optical planes are object and image planes related by an imaging system: points in one are imaged onto corresponding points in the other in the paraxial approximation. For a converging thin lens forming a real image in air, their distances $u,v>0$ obey $1/u+1/v=1/f$. Exchanging $u$ and $v$ preserves this relation; this symmetry gives the two settings of the Bessel lens displacement method.

The hydrodynamic radius is the radius of a hypothetical no-slip sphere with the same translational diffusion coefficient as the dissolved species. In the dilute continuum regime the Stokes–Einstein relation giveswhere $k_B$ is the Boltzmann constant, $T$ the absolute temperature, $\eta$ the dynamic viscosity of the solvent, and $D$ the translational diffusion coefficient. This effective radius need not equal the radius of gyration or a geometric molecular radius. It is a useful descriptor for SEC molar mass calibration, rather than a complete specification of how every shape enters every pore.

Toluene is methylbenzene, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_3$. It combines an aromatic ring with a benzylic methyl group, which creates reaction sites with different electronic environments.

It is a common organic solvent. Oxidation and substitution can affect either the side chain or the ring depending on reagents and mechanism, so identifying the reacting position is central to describing a toluene transformation.

Para-terphenyl contains three benzene rings connected in a line through para positions, with formula ${\mathrm{C}}_{18}{\mathrm{H}}_{14}$. The rings are linked by single bonds rather than fused along shared edges.

Inter-ring torsion affects conjugation and optical behavior, making it distinct from fused polycyclic aromatic hydrocarbons. Specifying para connectivity distinguishes it from the ortho and meta terphenyl isomers.

Pentacene is a linearly fused five-ring aromatic hydrocarbon, ${\mathrm{C}}_{22}{\mathrm{H}}_{14}$. Its extended conjugation and crystal packing make it relevant to organic-semiconductor research.

Charge transport in a solid depends on interactions between molecules as well as the electronic structure of an isolated molecule. Pentacene therefore connects molecular orbital ideas with the properties of an ordered molecular material.

An intersection graph has one vertex for each member of a family of sets. Two distinct vertices have an edge exactly when their associated sets have a nonempty intersection. A clique therefore describes pairwise intersections; it need not give a single element common to all those sets.