🏥 USMLE Exam Prep

Which of the following cellular structures is primarily responsible for synthesizing and packaging proteins destined for secretion or insertion into membranes?

A Smooth endoplasmic reticulum
B Mitochondria
C Rough endoplasmic reticulum
D Lysosomes

✓ Correct Answer: Option C

The rough endoplasmic reticulum (RER), studded with ribosomes, is the primary site for the synthesis, folding, and initial modification of proteins destined for secretion, membrane insertion, or delivery to other organelles like lysosomes.

💡 Why is C) the correct answer?

The correct answer to the question "Which of the following cellular structures is primarily responsible for synthesizing and packaging proteins destined for secretion or insertion into membranes?" is Option C: Rough endoplasmic reticulum.

The other options — A) Smooth endoplasmic reticulum, B) Mitochondria, D) Lysosomes — are incorrect for this USMLE Exam Prep question. As explained above: The rough endoplasmic reticulum (RER), studded with ribosomes, is the primary site for the synthesis, folding, and initial modification of proteins destined for secretion, membrane insertion, or deli…

📚 About This USMLE Exam Prep Practice Question

This 1-level USMLE Exam Prep question from the Step 1 – Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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