Prokaryotic 70S ribosomes are composed of which of the following subunits?

• A. 40S and 40S
• B. 40S and 50S
• C. 30S and 50S
• D. 30S and 40S
• E. 50S and 50S

Answer: (C)

Verified step by step guidance

1. Understand that ribosomes are the molecular machines responsible for protein synthesis in cells. They are composed of two subunits.
2. Recognize that prokaryotic ribosomes are referred to as 70S ribosomes, where 'S' stands for Svedberg units, a measure of sedimentation rate during centrifugation.
3. Identify the subunits of prokaryotic ribosomes: the smaller subunit is 30S and the larger subunit is 50S.
4. Note that the combination of the 30S and 50S subunits forms the complete 70S ribosome in prokaryotic cells.
5. Review the options given in the problem and match them with the correct subunit composition of prokaryotic ribosomes, which is 30S and 50S.