protein molecules and ion channels are embedded in membrane.
protein molecules and ion channels are embedded in membrane.
where are protein molecules and ion channels embedded?
membrane
like all animal cells, the cell body of every neuron is enclosed by a plasma membrane, a bilayer of lipid molecules with many types of protein structures embedded in it. a lipid bilayer is a powerful electrical insulator, but in neurons, many of the protein structures embedded in the membrane are electrically active. these include ion channels that permit electrically charged ions to flow across the membrane and ion pumps that chemically transport ions from one side of the membrane to the other. most ion channels are permeable only to specific types of ions. some ion channels are voltage gated, meaning that they can be switched between open and closed states by altering the voltage difference across the membrane. others are chemically gated, meaning that they can be switched between open and closed states by interactions with chemicals that diffuse through the extracellular fluid. the ion materials include sodium, potassium, chloride, and calcium.the interactions between ion channels and ion pumps produce a voltage difference across the membrane, typically a bit less than 1/10 of a volt at baseline. this voltage has two functions: first, it provides a power source for an assortment of voltage-dependent protein machinery that is embedded in the membrane; second, it provides a basis for electrical signal transmission between different parts of the membrane.
neuron
light-gated ion channel









































light-gated ion channels are a family of ion channels regulated by electromagnetic radiation. other gating mechanisms for ion channels include voltage-gated ion channels, ligand-gated ion channels, mechanosensitive ion channels, and temperature-gated ion channels. most light-gated ion channels have been synthesized in the laboratory for study, although two naturally occurring examples, channelrhodopsin and anion-conducting channelrhodopsin, are currently known. photoreceptor proteins, which act in a similar manner to light-gated ion channels, are generally classified instead as g protein-coupled receptors.









































section::::mechanism.
light-gated ion channel