Organelles II: Protein Sorting and Membrane Trafficking

These flashcards cover the key vocabulary and concepts related to protein sorting and membrane trafficking as discussed in the organelles lecture.

Protein Sorting

The process by which proteins are directed to their appropriate destinations within a cell.

Signal Theory

A theory proposed by Günter Blobel stating that proteins have intrinsic signals that govern their transport and localization within the cell.

Membrane Trafficking

The process that governs the transport of proteins and lipids to and from different membranes within the cell.

Cytosol

The liquid found inside cells, outside the organelles, which is the site for many metabolic processes.

Vesicle Formation

The process of creating membrane-bound sacs that can carry cargo (proteins, lipids) within the cell.

Vesicle Fusion

The merging of a vesicle with a target membrane to deliver its contents.

Chaperonins

Proteins that assist in the proper folding of other proteins post-translation.

Endoplasmic Reticulum (ER)

An organelle involved in the synthesis of proteins and lipids, consisting of rough (ribosome-studded) and smooth (lipid-synthesizing) regions.

Lysosome

An organelle containing digestive enzymes that break down waste materials and cellular debris.

Clathrin-coated vesicles

Vesicles that form around regions of the membrane, coated with clathrin, used for transporting molecules into cells.

Receptor-Mediated Endocytosis (RME)

A process in which cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane.

COPII-coated vesicles

Vesicles that transport proteins from the ER to the Golgi apparatus.

COPI-coated vesicles

Vesicles that transport proteins from the Golgi back to the ER.

Dynamin

A GTPase enzyme that is involved in the budding off of vesicles from membranes.

Rab Proteins

Small GTPases that play key roles in vesicle transport and membrane tethering.

Endosome

An intracellular membrane-bound compartment involved in the transport of materials brought into the cell.

Phagocytosis

The process by which cells engulf and digest large particles, such as bacteria.