Study Guide – CB Lecture 15 Golgi Apparatus – Structure and Function

A series of flashcards to assist in studying the key concepts related to the Golgi Apparatus, its structure, function, and the processes involved in protein sorting and modification.

What is the Golgi Apparatus?

A folded, membrane-bound organelle composed of stacked cisternae, functioning as the primary site for protein sorting, modification, and packaging.

What is the Cis Face of the Golgi Apparatus?

The 'receiving' side of the Golgi, facing the Rough Endoplasmic Reticulum (RER).

What is the Trans Face of the Golgi Apparatus?

The 'shipping' side of the Golgi, facing the plasma membrane.

What does Cisternal Maturation/Progression refer to?

The model where Golgi cisternae themselves mature, moving from cis to trans, carrying and processing proteins along the way.

What is a Vesicle?

A small, membrane-bound sac used to transport materials within the cell.

What is Anterograde Transport?

Forward movement of materials, for example, from RER to the Golgi.

What is Retrograde Transport?

Backward movement of materials, for example, from the Golgi to the RER.

Why is the polarity of the Golgi essential for its function?

The polarity (cis vs. trans) allows for proper sorting and processing of proteins; disruptions can lead to misallocation of proteins.

What type of vesicle coat is involved in the journey of a protein from the RER to the cis-Golgi?

COP-II vesicle coat.

What is the difference between COP-II and COP-I coats?

COP-II is involved in anterograde transport (RER to Golgi), while COP-I is involved in retrograde transport (Golgi to RER).

What are the three primary destinations for proteins that leave the trans-Golgi network?

1. Secretory vesicles 2. Lysosomes 3. Cell membrane.

What is the role of clathrin in the Golgi process?

Clathrin helps form vesicles that transport proteins to their correct locations.

What is the purpose of 'trimming' sugar residues during N-linked glycosylation?

Trimming modifies glycan structures to aid in proper protein folding and signaling.

What is the critical role of mannose phosphorylation?

It helps determine a protein's ultimate destination and fate by acting as a sorting signal.

Describe the pathway for recycling a worn-out membrane protein.

Endocytosis takes the membrane protein into an endosome, which fuses with a lysosome, and then proteins are directed back to the Golgi.

How does the recycling pathway demonstrate the Golgi's role as a central hub?

It integrates both the secretory and endocytic pathways, showing how the Golgi manages material flow in the cell.