Lecture 20: The Endomembrane System, Sorting and Vesicular Transport

Practice flashcards based on the key concepts from Lecture 20 regarding the endomembrane system, transport mechanisms, and associated organelles.

Endoplasmic Reticulum (ER)

An organelle involved in the synthesis of proteins destined for secretion or delivery to membrane-enclosed organelles.

Golgi Apparatus

An organelle that modifies proteins and lipids received from the ER and sorts them for transport to their destinations.

Nuclear Transport

The process of moving proteins and RNA into and out of the nucleus through nuclear pore complexes.

SRP (Signal Recognition Particle)

A protein-RNA complex that recognizes and binds to a signal peptide on nascent proteins, guiding them to the ER.

Co-translational Import

The process by which proteins are synthesized and translocated into the ER simultaneously.

Ran-GTPase

A GTP-binding protein that is involved in the transport of proteins across the nuclear pore by binding to importin.

Vesicular Transport

The process by which proteins and lipids are transported between different compartments of the endomembrane system via vesicles.

COPII Vesicles

Vesicles that transport proteins from the ER to the Golgi apparatus, involved in anterograde transport.

Clathrin-Coated Vesicles

Vesicles that transport proteins from the Golgi to lysosomes and from the plasma membrane to endosomes.

Lysosomes

Organelles that digest macromolecules and contain hydrolytic enzymes functioning optimally at a low pH.

Glycosylation

The process of adding carbohydrate moieties to proteins, critical for their proper function and localization.

vesicle budding

The process in which a vesicle forms from a membrane, typically assisted by a protein coat.

Lumen

The interior space of the endoplasmic reticulum or vesicles where proteins are folded and modified.

Autophagy

The process by which cells recycle damaged organelles and proteins in lysosomes.

Signal Peptide

A short peptide sequence that specifies the destination of a protein within the cell, crucial for targeting.

Translocators

Proteins that span membranes, facilitating the movement of other proteins across these membranes.

Cytosol

The fluid portion of the cytoplasm where many metabolic reactions occur and proteins are synthesized.

Endocytosis

The process by which cells internalize fluids and molecules from their environment.

Exocytosis

The process of vesicle fusion with the plasma membrane to release contents into the extracellular environment.

Rab GTPases

Proteins that provide specificity in vesicular transport by interacting with tethering proteins on target membranes.

Secretory Vesicles

Vesicles that transport substances to be secreted out of the cell.