Telomere
Definition
The repetitive DNA cap at the end of a chromosome, which shortens a little with each division. Telomere length is a popular and heavily disputed marker of biological ageing.
What this means for research sourcing
Cell-biology terms provide context for interpreting peptide research at the cellular level. See how these concepts apply to compounds Volta supplies for study.
Related Terms in Cell Biology
Active Site
The region of an enzyme where substrate binds and catalysis occurs. Inhibitors that occupy it compete directly with substrate, which is a different mechanism from binding elsewhere and changing the shape.
Biochemical Pathway
A linked series of reactions converting one molecule into another, each step usually enzyme-catalysed. Describing a compound as acting on a pathway says where it intervenes, not what the whole system does in response.
Homeostasis
The maintenance of internal conditions within a narrow range by opposing regulatory mechanisms. It is why a system perturbed in one direction usually produces a compensating response rather than a simple linear change.
Epigenetics
Changes in gene expression that do not alter the DNA sequence, such as methylation and histone modification. They are heritable through cell division and are one route by which a transient exposure has a lasting effect.
Biosynthesis
Production of a molecule by a living system rather than by chemical synthesis. Recombinant expression in bacterial or mammalian cells is the biosynthetic route to peptides too long to assemble stepwise.
Receptor
A protein, on the cell surface or inside it, that binds a specific molecule and converts that binding into a change in what the cell does. Which receptors a peptide binds, and how tightly, decides nearly everything about its behaviour.
Ligand
Any molecule that binds a defined site on a protein and changes what the protein does. A receptor's natural ligand is the endogenous signal; an agonist and an antagonist are both ligands with different consequences.
Enzyme
A protein that catalyses a reaction, raising its rate without being consumed. Enzymes build peptides and also destroy them, which is why proteases appear on both sides of peptide science.