Q.Describe the structural organisation of the Golgi apparatus, referring to its cisternae and its cis and trans faces, and briefly outline its role in the endomembrane system.

[!TLDR]

The Golgi is a stack of cisternae with a receiving cis face and dispatching trans face, processing ER-derived material for its endomembrane role. …

The Golgi apparatus is built from a stack of flattened, membrane-bound sacs called cisternae, arranged one above another like a pile of hollow discs, often curved into a shallow cup. The stack has a convex cis (forming) face, positioned closest to the endoplasmic reticulum, where transport vesicles arriving from the ER fuse and deliver their contents; and an opposite, concave trans (maturing) face, from which mature vesicles eventually bud off to carry their finished cargo to its destination -- another organelle, the plasma membrane, or release outside the cell. As material moves from the cis to the trans face, it is chemically modified (notably by glycosylation) by enzymes in the different cisternae. Within the broader endomembrane system, the Golgi apparat …

Describe the cisternae stack structure, then explain the cis-to-trans direction of material flow and …

Reversing the cis and trans faces -- the cis face receives from the ER, and the trans face is where finis …