Question

Which transport process is the main mechanism for the movement of most macromolecules by body cells?

Answer 1

Which transport process is the main mechanism for the movement of most macromolecules by body cells?

A. receptor-mediated endocytosis

B. pinocytosis

C. phagocytosis

D. secondary active transport

Answer:

A. receptor-mediated endocytosis

Explanation:

Receptor-mediated endocytosis is a highly selective type of endocytosis.  It is a process by which the cells take up specific ligands which in turn bind to specific receptors. This is followed by the formation  of a vesicle once a specific macromolecule in the extracellular fluid bind to its receptors. This process allows cells to take up LDLs, iron-transporting transferrin protein, antibodies, etc. The vesicles enter into the cell by the process of endocytosis.