Protein Sorting and Transport: The Endoplasmic Reticulum, Golgi Apparatus, and Lysosomes

These flashcards cover key vocabulary and concepts related to protein sorting and transport within eukaryotic cells, focusing on the roles of the endoplasmic reticulum, Golgi apparatus, and lysosomes.

Endoplasmic Reticulum (ER)

Membrane-bound organelle involved in protein synthesis and processing; has rough (with ribosomes) and smooth (without ribosomes) regions.

Rough ER

Part of the endoplasmic reticulum that is studded with ribosomes and is involved in the synthesis of proteins destined for secretion or for membranes.

Smooth ER

Part of the endoplasmic reticulum that is involved in lipid metabolism and lacks ribosomes.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Vesicular Transport

The process by which proteins and lipids are transported within vesicles from one cellular compartment to another.

Cotranslational Transport

The simultaneous translation and translocation of proteins into the endoplasmic reticulum.

Protein Glycosylation

The process of adding carbohydrate chains to proteins, which often occurs in the Golgi apparatus.

Signal Sequence

A short peptide sequence that directs the transport of a newly synthesized protein to its proper location.

Disulfide Bonds

Covalent bonds formed between cysteine residues in proteins, important for protein folding.

Unfolded Protein Response (UPR)

A cellular stress response related to the endoplasmic reticulum that aims to restore cellular homeostasis.

Lysosome

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

Autophagy

The process by which cells degrade and recycle their own components, often involving lysosomes.

SNARE proteins

Proteins that mediate the fusion of vesicles with their target membranes.

Translocon

A protein complex in the endoplasmic reticulum membrane that facilitates the translocation of polypeptides.