a These levels are based on Estimated Energy Requirements (EER) from the Institute of Medicine Dietary Reference Intakes macronutrients report, 2002, calculated by gender, age, and activity level for reference-sized individuals.
The definition of a channel is a waterway, a means of communication and a specific television or radio frequency. An example of channel is the English Channel. An example of channel is writing. An example of channel is Fox News.
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.