Question

Compare and contrast a gap junction and a tight junction from both a structural

Answer 1

gap junction	tight junction
1.it provide cytoplasmic channels to one cell to the neighboring cells. 2. they Directly connect the cytoplasm of two cells.	1.it prevents leakage of the extracellular fluids across epithelial cells 2. prevent the passage of molecules through cells.
3.it is similar to plasmodesmata of plant cells	3.they are formed by Transmembrane proteins that are claudins and occludins.
4. they are constructed by channel proteins, connexins and innexins	4. there are at least 4 proteins that compose this junction.
5.pannexin is a newly found protein that Function as single membrane channel that communicate with extracellular environment.	5.JAM molecules helps in maintaining polarity.
6.the gap between two intercellular space is 2-4 nm.	6. preventing the ion passage by forming of strands.