AP BIOLOGY

Detailed explanation-1: -Proteins and lipids are carried from the ER to the Golgi in transport vesicles that bud from the membrane of the ER and then fuse to form the vesicles and tubules of the ER-Golgi intermediate compartment (ERGIC).

Detailed explanation-2: -The modified proteins are encapsulated into transport vesicles that bud off from the ER. These vesicles are covered by a coating protein COPII (coat protein complex II) and are moved to the cis face of the Golgi (the Golgi is discussed in detail later in Chapter 17, Section 4).

Detailed explanation-3: -Correctly folded and assembled proteins in the ER are packaged into COPII-coated transport vesicles that pinch off from the ER membrane. Shortly thereafter the coat is shed and the vesicles fuse with one another to form vesicular tubular clusters, which move on microtubule tracks to the Golgi apparatus.

Detailed explanation-4: -Vesicles form by budding from membranes of ER, Golgi and the plasma membrane. Micrograph. Each bud has a distinctive coat protein on cytosol surface. The coat protein shapes the membrane into a bud.