Question

All of the proteins below should be retained by the ER instead of being sent to the Golgi except:

a) Integral membrane proteins
b) Soluble proteins
c) Lysosomal enzymes
d) Peroxisomal enzymes

Answer 1

Peroxisomal enzymes are the proteins that are not typically retained by the ER to be sent to the Golgi, as they are usually directed to peroxisomes.

Step-by-step explanation:

All of the proteins listed are typically processed through the endoplasmic reticulum (ER) and the Golgi apparatus, except for peroxisomal enzymes. To answer the question, peroxisomal enzymes should not be retained by the ER to be sent to the Golgi; instead, they are usually directed to peroxisomes. The process for others is as follows: Integral membrane proteins are synthesized and initially processed in the rough endoplasmic reticulum (RER), then transported to the Golgi for further modification before being incorporated into the plasma membrane. Soluble proteins can also be transferred to the Golgi where they may be secreted or directed to other locations in the cell. Lysosomal enzymes are specifically tagged for transport to lysosomes, and this tagging typically happens within the Golgi.