Cells have proteins called receptors that bind to signaling molecules and initiate a physiological response. Different receptors are specific for different molecules. Dopamine receptors bind dopamine, insulin receptors bind insulin, nerve growth factor receptors bind nerve growth factor, and so on.hosphate groups can be added to multiple sites in a single protein, and a single protein may in turn be the substrate for multiple kinases and phosphatases. At any one time, a cell is receiving and responding to numerous signals, and multiple signal transduction pathways are operating in its cytoplasm.
Definition of macropore. : a pore (as in coal) of comparatively large size; especially : a pore in soil of such size that water drains from it by gravity and is not held by capillary action.
rainfall or irrigation, under other conditions they are filled with air.Macropore or bypass ï¬ow may increase nutrient leaching following thesurface application of fertilizers, because a solution with high nutrientconcentration then inï¬ltrates rapidly into the soil with little contact withthe soil matrix.