lecture 5: Neurophysiology and Protein Transport

Flashcards covering key vocabulary related to neurophysiology and protein transport mechanisms.

Transmitter-gated ion channels

Channels that open in response to neurotransmitter binding, converting chemical signals into electrical signals at synapses.

Acetylcholine receptors

Transmitter-gated cation channels at the neuromuscular junction that mediate muscle contraction upon acetylcholine binding.

Signal sequences

A short peptide sequence that directs the transport of a protein to a specific location within the cell.

Protein translocation

The process of moving proteins across membranes into specific cellular compartments. specifically proteins from the cytosol into a compartment

Automatic inactivating mechanism

A regulatory process that quickly prevents further signaling by degrading or removing neurotransmitters or receptors after activation, ensuring that nerve signals do not persist unnecessarily.

Traveling action potential

A rapid change in electrical charge that propagates along the membrane of a neuron, transmitting signals across long distances. traveling only away from the site of depolarization

Gated transport

proteins and RNA molecules move between the cytosol and the nucleus through nucleus pore complexes, which function as selective gates

Vesicular transport

membrane enclosed transport intermediates ferry proteins between compartments

Engulfment

such as in autophagy, double membrane sheets wrap around portions of the cytoplasm, often including fragments or entire organelles

ER lumen

the internal space of the endoplasmic reticulum where protein folding and processing occur.

Rough ER

due to the abundance of ribosomes engaged in protein synthesis bound to the surface of this part of ER

Smooth ER

regions lack ribosomes and are dedicated to other ER functions, such as the biosynthesis and metabolism of lipids

Phosphoinositides

a specific class of lipids that serve as signaling molecules and are involved in cellular processes such as membrane trafficking and cytoskeletal organization.

Microsomes

are vesicle-like artifacts derived from fragmented endoplasmic reticulum, containing various proteins and lipids essential for studying membrane functions. still capable of protein glycosylation , protein translocation, and Ca uptake and release

Equilibrium density centrifugation

is a technique used to separate cellular components based on their density by layering a sample over a density gradient and centrifuging it.

Signal peptidase

is an enzyme that cleaves signal peptides from nascent polypeptides during protein translocation into the endoplasmic reticulum.

Signal recognition particle

is a ribonucleoprotein complex that recognizes and binds to the signal peptide of a nascent polypeptide, facilitating its translocation to the endoplasmic reticulum.

Sec61 complex

is a protein translocation channel in the endoplasmic reticulum that facilitates the insertion of nascent polypeptides into the membrane or their translocation into the lumen.

Cryo electrom microscopy

is a technique used to visualize the structures of biological specimens at very low temperatures, allowing for high-resolution imaging of proteins and complexes in their native state.