BIO 325 - Molecular Biology of the Cell - Chapter 12 - Membrane Transport

These flashcards cover key concepts from the lecture on membrane transport, including transport mechanisms, ion channels, and the processes related to neuronal signaling.

What are the two types of membrane transport proteins?

Channels and transporters.

What does passive transport mean?

Transport of molecules across a membrane without the use of energy, typically following a concentration gradient.

What role does the Na+-K+ pump play in membrane potential?

It pumps Na+ out of cells and K+ into cells, maintaining low Na+ and high K+ concentrations, contributing to the resting membrane potential.

What is the resting membrane potential for an average human cell?

About -73 mV.

How do ligand-gated ion channels function?

They open in response to the binding of a ligand, allowing specific ions to enter the cell.

What is facilitated diffusion?

A form of passive transport that uses transport proteins to help move molecules across the membrane.

What is the purpose of action potentials in neurons?

To transmit electrical signals along the axon and initiate neurotransmitter release at synapses.

What factors influence ion channel selectivity?

Size and charge of ions.

What happens during depolarization in action potentials?

Positive ions, primarily Na+, rush into the cell, causing the membrane potential to become more positive.

What triggers the release of neurotransmitters at synapses?

The influx of Ca2+ ions due to the opening of voltage-gated Ca2+ channels.

What are the three types of coupled transporters?

Uniporters, symporters, and antiporters.

What is the significance of the GLUT family of transporters?

They are tissue-specific glucose transporters that vary in affinity and play roles in glucose uptake.

How do action potentials propagate along axons?

They propagate in one direction due to the inactivation of Na+ channels and the sequential opening of voltage-gated channels.