Question

What structure is denoted by the number 5, and what is its function in the cell? Number 5 is pointing to the entire structure, not the dot.

Answer 1

The pointed structure is known as rough endoplasmatic reticulum (RER), what's more, we can see that it is covered by dots that represent ribosomes. RER is covered of ribosomes that unite amino acids forming proteins, these proteins enter the RER and there are modified and later sent to the Golgi apparatus for final modifications and packaging.