Dialysis is defined as the separation of small particles from large particles across a selectively permeable membrane. Figure 8 shows that small particles cross a sausage casing to leave the original solution while the large particle do not cross due their large size and stay in the sausage casing. This is the basic concept behind renal dialysis. Considering that we synthesize about 4 pounds of ATP per day, that comes to 1.6 pounds of ATP a day we use in these movements. The first active movement to be discussed is endocytosis.
Pinocytosis is similar to phagocytosis.
The substance to be internalized is called a substrate. The receptor is recycled to the membrane for re-use while the ligand in its endosome fuses with a lysosome to cause the destruction of the particle. The first is a mechanism that requires 2 sodium ions to go the opposite direction for every calcium ion that goes into or out of the cell, respectively. The calcium ion channel we can control is the receptor-mediated calcium ion influx mechanism. Uniports are transporters that transport a single molecule across a membrane.