[Campbell Biology P.156] How are hydrolytic enzymes and the lysosomal membrane's inner surfa... | Practice Question

How are hydrolytic enzymes and the lysosomal membrane's inner surface proteins protected from autodigestion within the lysosome, and where are these components primarily synthesized?

  • A: They are protected by a thick lipid bilayer, and synthesized exclusively in the smooth ER.
  • B: Their three-dimensional shapes protect vulnerable bonds, and they are made in the rough ER before transfer to the Golgi apparatus.
  • C: They are continuously degraded and replaced, and primarily formed by budding from the plasma membrane.
  • D: The low pH environment inactivates them until needed, and they are spontaneously assembled in the cytosol.

Explanation

Hydrolytic enzymes and lysosomal membrane proteins are protected from the acidic environment and autodigestion by their specific three-dimensional shapes, which protect vulnerable bonds from enzymatic attack. These proteins and membrane components are primarily synthesized in the rough ER and then transferred to the Golgi apparatus for further processing and sorting, from where lysosomes arise by budding from the trans face.