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.
Receptors that activate transmembrane ion channels. These channels are called 'ligand-gated ion channels'. Receptors that use as their transducer the 'G-protein'. Often these receptors can couple promiscuously with several different G-proteins, who are in turn not particularly faithful to a single receptor.