Lysosomes are the Principal Site of Cellular Digestion

Question

Lysosomes are the principal site of cellular digestion. They …
A) normally maintain a pH of about 2.0 to 2.5.
B) contain F-type ATPases that pump protons into the organelles.
C) contain heavily glycosylated membrane proteins.
D) are homogeneous in size and shape.
E) All of the above.

Accepted Answer

Lysosomes vary greatly in size and shape, reflecting their various functions. They maintain a low interior pH of about 4.5-5.0 using lysosomal V-type ATPases. Their own membrane proteins are highly glycosylated to protect them from digestion by the proteases in the lumen.