These ion channels are protein molecules that act as a passageway which span across the cell membrane allowing the movement of ions from one side of the membrane to the other. They possess the ability to open and close in response to either chemical or mechanical signals.They possess a fluidic pore, which becomes available to ions after a conformational change in the protein structure has been activated causing the ion channel to open. Based on the stimulus to which they respond, ion channels are divided into three groups: voltage-gated, ligand-gated and mechano-sensitive ion channels. Channels responding to electrical (voltage-dependent ion channels), mechanical, or chemical (ligand-gated ion channels) stimuli open and allow rapid ion movement into or out of the cell, and this movement creates an electrical signals.
This means all living organisms must obtain and use energy to live. Energy is the power to do things. ... A living organism can either make its food or depend on others to make food for them. For example, green plants produce their food from a process called photosynthesis.