Neurobiology and Ion Channels Lecture Flashcards

Vocabulary flashcards focusing on cellular neurobiology, axonal transport mechanisms, membrane biophysics, and the functional properties of ion pumps and channels.

Action potential

A specific type of electrical stimulation that conducts down a neuron's axon to convey signals to other cells.

Skeletal muscle cells

Elongated continuous cells containing multiple nuclei, allowing for localized protein synthesis throughout the cell.

Axonal protein transport

A slow, catalyzed cellular process that transports proteins synthesized in the cell body down the axon to locations like the synapse over several hours to tens of hours.

Clathrate structure

A dynamic cage-like arrangement of water molecules formed around neutral, non-ionic molecules in aqueous solution.

Sodium-Potassium Pump

An ATP-driven transmembrane protein mechanism that continuously pumps sodium out of the cell and potassium into the cell against their chemical gradients.

Transmembrane protein

A protein that inserts across the cell membrane, possessing hydrophilic regions facing aqueous environments on either side and a hydrophobic middle section embedded in the lipid bilayer.

Ion channel

A fast-acting, energetically neutral protein complex with a water-filled core that allows specific ions to pass across the cell membrane passively without using ATP.

Water shell (Hydration shell)

A transient conglomerate of water molecules bound to an ion, which alters its effective physical size as it passes through membrane channels.

Alpha helix

A spiral protein secondary structure commonly found in transmembrane protein segments that presents hydrophobic amino acid groups to the lipid bilayer interior.

Ligand-gated channel

An ion channel that alters its conformation to open or close upon the binding of a specific chemical signal to its receptor site.

Acetylcholine-gated channel

A ligand-gated channel whose probability of opening increases significantly when bound by the neurotransmitter acetylcholine.

Glass electrode

A micro-instrument created by heating and pulling a glass capillary tube into a microscopic needle with an open channel, used to measure cellular electrical potential and channel currents.

Voltage-gated channel

An ion channel whose opening or closing is triggered by changes in the electrical potential difference across the cell membrane.

Inactivated state

A specific closed conformation of a gated ion channel in which the channel cannot immediately reopen, even under conditions that normally favor opening.