The directed movement of a dipeptide across a membrane by means of some agent such as a transporter or pore. A dipeptide is a combination of two amino acids linked together by a peptide (-CO-NH-) bond.

The directed movement of oligopeptides into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Oligopeptides are molecules that contain a small number (2 to 20) of amino-acid residues connected by peptide linkages.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

The component of the plasma membrane consisting of the gene products and protein complexes having at least some part of their peptide sequence embedded in the hydrophobic region of the membrane.

A complex for the transport of metabolites into the cell, consisting of 5 subunits: two ATP-binding subunits, two membrane spanning subunits, and one substrate-binding subunit. In organisms with two membranes, the substrate-binding protein moves freely in the periplasmic space and joins the other subunits only when bound with substrate. In organisms with only one membrane the substrate-binding protein is tethered to the cytoplasmic membrane and associated with the other subunits. Transport of the substrate across the membrane is driven by the hydrolysis of ATP.