Question

question 1
which of the following is a membranous organelle containing ribosomes that functions in the synthesis and modification of proteins?

mitochondria

smooth endoplasmic reticulum (ser)

rough endoplasmic reticulum (rer)

golgi apparatus

Explanation:

• Mitochondria: Mainly for energy (ATP) production, not primary protein synthesis with ribosomes on its membrane.
• Smooth Endoplasmic Reticulum (sER): Lacks ribosomes, involved in lipid synthesis, detoxification, etc.
• Rough Endoplasmic Reticulum (rER): Has ribosomes attached to its membranes. Ribosomes synthesize proteins, and rER modifies these newly synthesized proteins (e.g., folding, adding sugars).
• Golgi Apparatus: Modifies, sorts, and packages proteins (and lipids) received from ER, but it does not have ribosomes and is not the site of initial protein synthesis with ribosomes.

Answer:

C. Rough Endoplasmic Reticulum (rER)