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.
Because ions are charged and water-soluble, they must move through small tunnels or channels (specialized proteins) that span the cell membrane's lipid bilayer. Each channel is specific for only one type of ion. There are specific channels for sodium ions, potassium ions, calcium ions and chloride ions. These channels make the cell membrane selectively permeable to various ions and other substances (like glucose).