Amino Acids to Proteins Amino acids are absorbed through the basal membrane of the cell by several specific amino acid transport systems. Newly synthesized proteins are transferred from the RER to the Golgi apparatus where they are processed for transport out of the cell. Caseins and other proteins undergo post-translational processing in the Golgi. The secretory vesicles do not transfer to the basolateral membrane. At the apical membrane, the membrane of the secretory vesicle fuses with the inner surface of the apical membrane, resulting in an opening through which the vesicle contents are discharged into the alveolar lumen .
Some glucose is converted to galactose.
The formation of lactose in the Golgi results in drawing water into the cell, into the Golgi, and ultimately becoming part of milk. Note that the Golgi apparatus is involved in processing of milk proteins, synthesis of lactose, and the osmotic draw for water. The Golgi apparatus is very important to the synthesis of skim milk components. These precursors are absorb through the basolateral membrane. In addition, preformed fatty acids, glycerol, and monoacylglycerides are absorbed at the basolateral membrane.