Question

Multicellular organisms have a complex organization of cells into tissues. Discuss the roles of cell-cell adhesion and cell communication in forming these structures. Be sure to address these processes in molecular detail.

Answer 1

Multicellular organisms organization is quite complex. Multicellularity in eukaryotes cause cell differentiation which make them organized into groups (tissue) .When these tissues perform specialized function together in groups ,they form organs. Certain cell properties such as rapid cell division and differntiation help a single cell (zygote) to nearly 100 trillion cells ( human body).

These occurs with the cells ability to contact tightly and interact specifically with neighbouring cells . This is facilitated by various integral proteins like CELL ADHESION MOLECULES (CAMs)
Function: make cells to adhere tightly with cells of similar type specifically this helps in segregate cells into tissue to perform distinct functions.CELL JUNCTIONS between them stabilize the connection and modulate local communication between adjacent cells followed by aggregation. EXTRA CELLULAR MATRIX ( contain many hormones that helps in cell growth and differentiation and act as lattice for cell movement )along with proteins and carbohydrates creates special surrounding in gaps between cells .Extra cellular matrix components are proteoglycan - cushions cell; collagen - provide strength and resilience ; multi adhesive proteins - binding function , all together they function as an imaginary frame that supports cell .It communicates with intracellular signalling pathway for carrying out specific functions.As they form organs with specialized function the cells get remodeled, degraded and resynthesized in life time.

Cell adheshion molecules and cell junction helps maintain structure in overall process without any malfunctioning that can lead to maldevelopment, it helps cell to organize into tissue level and further into organ level