Cattle : âBeefâ cattle slaughtered at 18 months young; dairy cows slaughtered at 4 to 5 years young; Natural life span: 18 to 25+ years. Veal Calves: Slaughtered at 16 weeks young; Natural life span: 18 to 25+ years. Goats: Slaughtered at 3 to 5 months young; Natural life span: 12 to 14 years.
Definition of Ion channel. Ion channel: A protein that acts as a pore in a cell membrane and permits the selective passage of ions (such as potassium ions, sodium ions, and calcium ions), by means of which electrical current passes in and out of the cell.
The cell membrane is permeable to a number of ions, the most important of which are Na+, K+, Ca++ and Cl-. These ions pass across the membrane through specific ion channels that can open (become activated) and close (become inactivated). Therefore, these channels are said to be gated channels.