C2

A cell that can actively change its membrane potential.

The difference in electrical potential between the inside and outside of a cell.

The membrane potential of a cell when it is not actively signaling.

A device used to measure the electrical potential across a cell's membrane.

The typical resting membrane potential of most cells, about -70mV.

The unequal distribution of ions across the cell membrane, creating a potential difference.

Proteins embedded in the cell membrane that allow specific ions to pass through.

Proteins that transport ions across the cell membrane, often against the concentration gradient.

A type of ion channel that is always open, allowing ions to continuously pass through the membrane.

A type of ion channel that can be either open or closed, controlled by specific factors like ligands, phosphorylation, voltage, or stretch.

A molecule that binds to a specific site on a gated channel and triggers its opening, allowing ions to flow across the membrane.

A natural ligand that specifically binds to a gated channel and opens it.

A molecule that resembles an endogenous agonist and binds to the same site on a gated channel, either mimicking or blocking its action.

A molecule that resembles an endogenous agonist and binds irreversibly to a gated channel, permanently blocking its function.

The ability of an ion channel to preferentially allow the passage of one type of ion over another.

A measure of how easily ions can flow across the membrane through a channel, determined by the number of open channels and the channel's properties.

The movement of ions across a membrane driven by differences in concentration.

The force that drives ion movement due to the difference in electrical charge across a membrane.

A state where there is no net movement of ions across a membrane, even though individual ions may still be moving.

The movement of ions across a membrane driven by differences in concentration and electrical charge.

The movement of ions across a membrane from a region of high concentration to a region of low concentration.

The movement of ions across a membrane against their concentration gradient, requiring energy.

The process where the electrical gradient opposes the chemical gradient, slowing down or stopping ion movement.

The force that drives an ion across a membrane, influenced by both the concentration difference and the electrical potential difference.

The potential difference across a membrane when the net movement of a specific ion is zero, meaning the electrochemical driving force is balanced.

The difference between the actual membrane potential and the equilibrium potential of an ion.

The process of moving ions across a membrane through channels or pores, without requiring energy.

The movement of electrically charged ions across the cell membrane, creating electrical currents.

The ability of the membrane to allow certain ions to pass through more easily than others. This is crucial for establishing the membrane potential.

A protein embedded in the cell membrane that actively pumps sodium ions out of the cell and potassium ions into the cell, against their concentration gradients.

The Na-K pump does not directly determine the membrane potential. It plays a crucial role in maintaining the ion gradients that underlie the membrane potential.

The efficiency of the Na+/K+ pump is higher when the substrate concentration is higher. This is because increased substrate concentration increases the probability of chemical reactions, leading to a faster reaction rate.

Removing external potassium (K+) or using metabolic inhibitors reduces the efflux of sodium (Na+) from the cell, indicating a decrease in the pump's efficiency.

Sodium efflux (Na+ moving out) is easier to measure than potassium influx (K+ moving in) because extracellular sodium levels are more readily accessible.

The membrane's low permeability to ions due to limited leak channels helps maintain the separation of ionic species, creating a potential difference between the inside and outside of the cell.

The resting membrane potential, a cell's baseline electrical charge, is determined by the membrane's selective permeability to different ions. This permeability can be quantified by considering both the concentration gradient and electrical gradient of each ion.

An electrical equivalent circuit is a model used to understand how different ions contribute to the membrane potential over time. It uses components like resistors (representing ion channels), capacitors (representing the membrane), and batteries (representing Na-K pumps).

The resting potential is considered the 'default' state for all cells, while the active potential is specific to excitable cells. The active potential is a change in membrane potential from the resting state.

Blood tests can provide insights into interstitial fluid as they are in close communication. Blood tests are useful because they can give information about the interstitial fluid.