Change in the voltage across the membrane, ligand binding, and mechanical stress.
The three types of gated channels are voltage-gated channels, ligand-gated channels, and mechanically-gated channels. Voltage-gated channels open or close in response to changes in membrane potential, while ligand-gated channels respond to the binding of specific molecules (ligands). Mechanically-gated channels open in response to physical changes in the environment, such as pressure or stretch. Each type plays a crucial role in cellular signaling and communication.
Gated channels open in response to specific stimuli, which can be classified into three main types: voltage-gated channels respond to changes in membrane potential, ligand-gated channels open when a specific neurotransmitter or other molecule binds to them, and mechanically gated channels respond to physical deformation, such as stretching or pressure. Each of these channels plays a crucial role in cellular signaling and communication.
The gates on the ion channel may open or close to three kinds of stimuli: 1. Stretching of the cell membrane 2. electrical signals 3. Chemicals in the cytosol or external environment
The three major types of stimuli for endocrine glands are: Humoral stimuli, which respond to changes in blood levels of ions or nutrients. Neural stimuli, which are initiated by the nervous system. Hormonal stimuli, which are triggered by other hormones from the hypothalamus or anterior pituitary gland.
All action of neurotransmitter is eventually (mostly) manifest in the regulation of ion in nerve cell, to decide when to fire or not an action potential. Regulation of ion utilize the ion channel, and there are three (known) mechanism which affect the opening and closing of an ion channel : 1) direct influence - ion channel which is directly activated by neurotransmitter attached to them, this one is called ¨Transmitter Gated Channel¨ 2) shortcut pathways - ion channel which is activated by G-protein, this is called the ¨G-protein-gated ion channels¨ 3) second messenger cascades - G-protein trigger a chain reaction of chemical through enzyme or other class of protein and finally affect the opening and closing of ion channels
Three.
Resting membrane potential is determined by K+ concentration gradient and cell's resting permeability to K+, N+, and Cl-.Gated channels control ion permeability. Three types of gated channels are mechanically gated, chemical gated, voltage gated. Threshold voltage varies from one channel type to another.The Goldmann- Hodgkins-Katz Equation predicts membrane potential using multiple ionsThe resting potentialBecause the plasma membrane is highly permeable to potassium ions, the resting potential is fairly close to -90mV, the equilibrium potential for K+Although the electrochemical gradient for sodium ions is very large, the membrane's permeability to these ions is very low. Consequently, Na+ has only a small effect on the normal resting potential, making it just slightly less negative than it would be otherwise.The sodium-potassium exchange pump ejects 3 Na+ ions for every 2 K+ ions that it brings into the cell. It thus serves to stabilize the resting potential when the ratio of Na+ entry to K+ loss through passive channels is 3:2.At the normal resting potential, these passive and active mechanisms are in balance. The resting potential varies widely with the type of cell. A typical neuron has a resting potential of approx -70mV
Three examples of stimuli that skin can respond to are temperature changes (hot or cold), touch or pressure, and exposure to chemicals or irritants.
The three different types of stimuli are physical, chemical, and biological stimuli. Physical stimuli include changes in the environment, such as light, sound, and temperature. Chemical stimuli involve the presence of specific molecules, like odors or taste substances, that can trigger sensory responses. Biological stimuli refer to living organisms or their activities, such as the presence of predators or mating calls that elicit reactions from other organisms.
Gated channels are important in transporting ion and other necessary molecules. Cells need to maintain a balance with their environment. If ions could freely diffuse through the plasma membrane, the right ionic environment required for cellular reactions is not met. In the absence of the right ionic environment, many cellular reactions might stop. Therefore, there is a requirement for gates through which ions can travel into and out of the cell. A typical example is the sodium-potassium channel. Here, the entry of three sodium ions is balanced out by the exit of 2 potassium ions. This is how the gate is designed. Another example includes gates for the entry and exit of glucose molecules, a necessary nutrient for mammalian cells
light and sound hunger
There are three main events that are considered stimuli for erythropoiesis. These are aerobic exercises, living in an environment with a high altitude, and hemorrhages.