Final answer:
Proteins to be incorporated into lysosomes are not made on free ribosomes; they are synthesized on bound ribosomes in the rough ER.
The correct answer is 4.
Step-by-step explanation:
The question pertains to the site of protein synthesis and where different types of proteins are made in a cell. Specifically, it deals with the distinction between free ribosomes and ribosomes bound to the endoplasmic reticulum (ER). Proteins synthesized on bound ribosomes on the rough ER are those destined for secretion, incorporation into the plasma membrane, or inside various organelles. These bound ribosome-synthesized proteins do not end up in the cytosol but are rather sequestered inside membrane-bound compartments. In contrast, proteins made on free ribosomes are usually those that function within the cytosol.
Given the four options listed in the question:
- proteins to be incorporated into peroxisomes
- proteins to be incorporated into chloroplasts
- proteins to be incorporated into mitochondria
- proteins to be incorporated into lysosomes
Proteins destined for the lysosomes are synthesized on bound ribosomes in the rough ER and not on free ribosomes. Proteins for peroxisomes, chloroplasts, and mitochondria are typically synthesized on free ribosomes in the cytosol.
The correct answer is (4) proteins to be incorporated into lysosomes