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 rental agreement sets up a contract between the landlord and the resident for a short period of time, usually one month. Such a month-to-month rental agreement is automatically renewed each month unless either the landlord or the resident gives the other proper notice â usually 30 days.