Question

Which of the models below suggests that the Golgi cisternae are transient structures that form at the cis face of the stack by fusion of membranous carriers from the ER and ERGIC and that each cisterna travels through the Golgi complex from the cis to the trans end of the stack, changing in composition as it progresses?

1) Model A: The Golgi cisternae are static structures that do not change in composition as they progress through the Golgi complex.
2) Model B: The Golgi cisternae are dynamic structures that form at the trans face of the stack and move backwards through the Golgi complex.
3) Model C: The Golgi cisternae are transient structures that form at the trans face of the stack by fusion of membranous carriers from the ER and ERGIC.
4) Model D: The Golgi cisternae are static structures that form at the trans face of the stack and do not change in composition as they progress through the Golgi complex.

Answer 1

None of the models (A, B, C, D) provided perfectly matches the description of the Golgi cisternae as transient structures that form at the cis face and mature as they move towards the trans face. The cisternal maturation model, not listed among the options, better describes this concept where the cisternae change in composition as proteins move through the Golgi apparatus.

Step-by-step explanation:

The model that suggests the Golgi cisternae are transient structures that form at the cis face of the stack by fusion of membranous carriers from the ER and ERGIC and that each cisterna travels through the Golgi complex from the cis to the trans end of the stack, changing in composition as it progresses, is not explicitly listed among the options provided. However, based on the descriptions, none of the models A to D perfectly match this description. The closest model representing this process would ideally state that the Golgi cisternae constantly form at the cis face, mature as they move towards the trans face, undergoing alterations such as glycosylation or phosphorylation, and eventually be packaged and sent to their destination.

The provided models depict static cisternae (A and D) and dynamic cisternae forming at the trans face, either without changing composition (D) or moving backwards (B), or transient structures forming at the trans face (C). Therefore, to answer your question, none of the provided models (A, B, C, D) accurately describes the process you outlined. For better clarity on the Golgi apparatus and its dynamic nature, consult a current biology textbook that includes the concept of cisternal maturation, which aligns with your description.