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# Membrane Potential The image displays a diagram of a cell membrane, focusing on ion channels and their roles in maintaining the membrane potential. **Components and Processes:** * **Extracellular fluid:** contains ions like chloride (Cl⁻). * **Intracellular fluid (Cytosol):** contains ions lik...

# Membrane Potential The image displays a diagram of a cell membrane, focusing on ion channels and their roles in maintaining the membrane potential. **Components and Processes:** * **Extracellular fluid:** contains ions like chloride (Cl⁻). * **Intracellular fluid (Cytosol):** contains ions like potassium (K⁺) and phosphate (likely a phosphate ion). * **Membrane:** A phospholipid bilayer, shown in light green, forming a barrier between the extracellular and intracellular environments. * **Ion Channels:** Different types of channels are depicted, allowing specific ions to pass through the membrane. Passive channels for K⁺ and Na⁺ (yellow and orange in image respectively) are shown. * **Na⁺/K⁺ ATPase:** This is visualized as a large pink pump actively transporting ions against their gradient. Specifically, it pumps 3 Na⁺ ions out and 2 K⁺ ions into the cell. ATP (adenosine triphosphate) is required for this active transport process. * **Ligand-gated ion channels:** These gated channels are activated when a ligand binds to a receptor site. (The specific ligand and mechanisms are not explicit in the diagram). * **Ionotropic Channels:** These channels are directly coupled to the binding site. Shown as a larger channel, it opens a nearby ion channel in response to an incoming ligand molecule. * **Metabotropic Channels:** This type of channel is indirectly coupled to the binding site. Involves a signaling cascade. * **Calcium (Ca²⁺):** shown moving across the membrane, indicating the role of calcium as a signaling ion, and affecting enzymes. The presence of an enzyme is also indicated. * **Depolarization:** The influx of Na⁺ is shown as causing depolarization (PPE). * **Hyperpolarization:** The efflux (outward movement) of K⁺, and the influx of Cl⁻, are shown as causing hyperpolarization (PPI). **Summary:** The diagram illustrates the different types of ion channels involved in maintaining and changing the membrane potential across a cell membrane. It highlights the concepts of passive diffusion (through channels), active transport (using ATPase), and the roles of specific ions like sodium, potassium, and chloride in these processes. **Ionotropic vs metabotropic:** The diagram explicitly labels both ionotropic and metabotropic types of channels to show distinction in the methods employed for activation.