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.
Cells in higher organisms may express more than 100 different types of ion channel, each with different selectivity and different gating properties. Function and structure. The flow of charged ions through open channels represents an electrical current that changes the voltage across the membrane by altering the distribution of charge.