CELS191 Lecture 4: Endomembrane System & Bulk Transport Processes

Vocabulary flashcards covering the components and functions of the endomembrane system, as well as bulk transport processes including endocytosis and exocytosis.

Endomembrane system

A membrane system interconnected by direct physical contact or transfer by vesicles, including the nuclear envelope, endoplasmic reticulum, Golgi apparatus, vesicles, lysosomes, vacuoles, and plasma membrane.

Smooth Endoplasmic Reticulum (sER)

A region of the ER involved in carbohydrate metabolism, lipid synthesis for membranes, detoxification of drugs and poisons, and the storage of calcium ions.

Rough Endoplasmic Reticulum (rER)

A region of the ER that appears rough due to ribosomes and is involved in the synthesis of secreted and membrane-bound proteins.

Lumen

The interior of the rough endoplasmic reticulum (rER) where secreted and membrane-bound proteins enter for processing.

Golgi Complex

A series of membrane sacs and associated vesicles that receives, modifies, sorts, and ships proteins arriving from the rER.

Cis face

The polarity side of the Golgi apparatus where vesicles from the endoplasmic reticulum arrive.

Trans face

The polarity side of the Golgi apparatus from which processed vesicles leave.

Glycosylation

The addition or modification of carbohydrates to proteins, which is important for secreted or cell surface proteins.

Mannose 6-phosphate

A special phosphorylated sugar that identifies proteins destined to become lysosomal enzymes.

Liposomes

Artificial vesicles used for the delivery of drugs and vaccines.

Exocytosis

The process of transporting material, such as glycoproteins, out of the cell or delivering them to the cell surface.

Constitutive exocytosis

A form of exocytosis that releases extracellular matrix proteins.

Regulated exocytosis

A form of exocytosis that releases hormones and neurotransmitters.

Endocytosis

The process by which the cell takes in molecules and particulate matter at the plasma membrane.

Phagocytosis

A type of endocytosis referred to as cell 'eating,' involving the uptake of 'food' particles to form a phagocytic vacuole.

Pinocytosis

A non-selective type of endocytosis referred to as cell 'drinking,' involving the uptake of extracellular fluid containing various solutes.

Receptor-mediated Endocytosis

A specialized form of pinocytosis using receptor proteins to selectively capture bulk quantities of specific substances.

Lysosomes

Membrane-bound organelles containing hydrolytic enzymes with an acidic interior used to degrade proteins, lipids, carbohydrates, and nucleic acids.

Autophagy

The lysosomal process of digesting and recycling unwanted cellular materials to maintain cell health.

Vacuoles

Large vesicles derived from the rER and Golgi; in plants, the large central vacuole absorbs water to allow cell growth.