Endomembrane System, Golgi, Lysosomes, Phagocytosis, Autophagy – Practice Flashcards

A set of practice flashcards covering the Golgi apparatus, vesicle traffic, lysosomes, phagocytosis, autophagy, vacuoles, and the plant/fungal endomembrane system based on the lecture notes.

What are the three main functions of the Golgi apparatus?

Modify products of the ER; manufacture certain macromolecules; sort and package materials into transport vesicles.

What is the structure of the Golgi apparatus?

Flattened membranous sacs called cisternae.

What are the cis face and trans face of the Golgi, and what does each do?

Cis face is the receiving side that receives vesicles from the ER; Trans face is the shipping side that sorts and dispatches vesicles for secretion.

What is cisternal maturation in the Golgi?

Golgi cisternae move in a cis-to-trans direction, maturing as they progress through the Golgi.

From where do vesicles arrive to enter the Golgi, and in which direction do cisternae progress?

Vesicles arrive from the ER to the Golgi; cisternae progress cis to trans.

What is the trans-Golgi network?

A region at the trans face where vesicles bud off and are directed to their final destinations (e.g., plasma membrane, lysosome).

What is retrograde transport in the Golgi?

Some proteins are transported backward to newer Golgi cisternae or back to the ER.

What is a vesicle?

A small membrane-bound sac that transports materials within or outside the cell.

What do the abbreviations CCV, COPI, and COPII refer to?

CCV: clathrin-coated vesicles; COPI and COPII: coat proteins I and II that mediate vesicle transport in the endomembrane system.

What is a lysosome?

A membranous sac containing hydrolytic enzymes that digest proteins, fats, polysaccharides, and nucleic acids; also involved in autophagy.

What processes involve lysosomes?

Digestion of macromolecules and autophagy (recycling of organelles and macromolecules).

What is phagocytosis?

Cellular process by which a cell uses its plasma membrane to engulf large particles (≥0.5 μm) forming a phagosome.

What is a phagosome?

Internal compartment formed by phagocytosis that fuses with a lysosome for digestion.

What is autophagy?

Conserved degradation of cellular components via lysosome-dependent mechanisms to remove unnecessary or dysfunctional components.

What is a vacuole?

A membrane-bound sac with varied functions; plant and fungal cells may have one or more vacuoles.

What is the central vacuole in plant cells?

Stores water and organic compounds and helps maintain turgor pressure.

What types of vacuoles are described in the notes?

Food vacuoles (formed by phagocytosis), contractile vacuoles (pump out excess water), central vacuole (storage of water and nutrients).

What is the endomembrane system?

A complex, interconnected network including the nuclear envelope, ER, Golgi apparatus, lysosomes, vesicles, and plasma membrane that coordinates transport and secretion.

How do vesicles contribute to the secretion pathway from the Golgi to the plasma membrane?

Vesicles bud from the trans-Golgi network and fuse with the plasma membrane to secrete contents (exocytosis).

What is the role of the rough endoplasmic reticulum in the endomembrane system?

Synthesizes proteins destined for the Golgi, lysosomes, plasma membrane, or secretion.

What major components form the endomembrane system and how are they connected?

Nuclear envelope, nucleus, rough ER, smooth ER, transport vesicles, cis Golgi, trans Golgi, and plasma membrane, connected by vesicular transport.