Final answer:
Large molecules such as proteins and nucleic acids cannot pass through gap junctions due to size constraints, as gap junctions allow only water and small solutes to pass between adjacent cells.
Step-by-step explanation:
The type of molecule that does not pass through a gap junction is typically a large molecule, such as proteins or nucleic acids. Gap junctions are composed of proteins called connexins which form a channel allowing the passage of water and small solutes between cells. However, due to size constraints, large molecules like proteins and nucleic acids are unable to pass through these channels. Consequently, gap junctions facilitate cellular communication by permitting the transfer of ions and small molecules, but prevent macromolecules from moving between cells, which helps maintain cell specificity and function.
Gap junctions are protein-lined pores that allow water and small molecules to pass between adjacent animal cells. However, larger molecules like proteins and nucleic acids cannot pass through the gap junctions. The charge of ions and the size of larger polar molecules prevent them from freely diffusing through the gap junctions. Instead, these molecules require other means of transport across the plasma membrane.