calcium pump. the mechanism of active transport of calcium (Ca 2+) across a membrane, as of the sarcoplasmic reticulum of muscle cells, against a concentration gradient; the mechanism is driven by hydrolysis of ATP.
A rental agreement differs from a lease agreement in that it is not a long-term contract and usually occurs on a month-to-month basis. This month-to-month lease agreement expires and then renews each month upon agreement of the parties involved.
A lease is a contractual arrangement calling for the lessee (user) to pay the lessor (owner) for use of an asset. Broadly put, a lease agreement is a contract between two parties, the lessor and the lessee. The lessor is the legal owner of the asset, the lessee obtains the right to use the asset in return for rental payments. The narrower term rental agreement can be used to describe a lease in which the asset is tangible property. Language used is that the user rents the land or goods let or rented out by the owner.