Which type of ribosome is typically smaller, found in prokaryotic cells?

In prokaryotic cells, ribosomes are classified as 70S ribosomes. This size designation reflects their sedimentation rate, which is a measure that relates to both their size and shape. The 'S' stands for Svedberg units, a way of measuring how quickly particles sediment when spun in a centrifuge.

The smaller size of 70S ribosomes in prokaryotes is an important factor because it allows for more efficient protein synthesis in these simpler cells, which lack membrane-bound organelles. In contrast, eukaryotic cells have larger ribosomes classified as 80S, which are more complex and play a role in the more intricate cellular processes found in these organisms.

Understanding the difference in ribosomal sizes is critical in biology, as it informs us about the cellular structures and functions that differentiate prokaryotic and eukaryotic organisms. This information is foundational for comprehending the broader biological principles of gene expression and protein synthesis across different life forms.