key term - 70s

Definition

The term '70s refers to the ribosomal subunits found in prokaryotic cells, specifically 70S ribosomes. These ribosomes play a crucial role in protein synthesis within prokaryotic organisms like bacteria, consisting of two subunits: a small 30S subunit and a larger 50S subunit. The 'S' stands for Svedberg units, which indicate the rate of sedimentation during centrifugation, reflecting their size and shape rather than mass.

5 Must Know Facts For Your Next Test

1. 70S ribosomes are primarily found in prokaryotes, such as bacteria, and are essential for their ability to produce proteins.
2. The small 30S subunit of the 70S ribosome contains 16S rRNA and several proteins, while the large 50S subunit consists of 23S rRNA, 5S rRNA, and more proteins.
3. Prokaryotic ribosomes are smaller and structurally different from eukaryotic ribosomes, which is significant for antibiotic targeting without harming eukaryotic cells.
4. The assembly of 70S ribosomes occurs in the cytoplasm of prokaryotic cells and is vital for translating mRNA into proteins efficiently.
5. Differences in ribosomal structure between prokaryotes and eukaryotes can be exploited in medical treatments, as some antibiotics specifically inhibit the function of 70S ribosomes.

Review Questions

• How does the structure of the 70S ribosome differ from that of the 80S ribosome, and what implications does this have for protein synthesis?
  • The structure of the 70S ribosome consists of a small 30S subunit and a larger 50S subunit, making it smaller than the 80S ribosome, which is composed of a 40S small subunit and a 60S large subunit. This difference in size and composition affects how each type of ribosome interacts with mRNA and tRNA during protein synthesis. The smaller size of the 70S ribosome allows it to efficiently translate mRNA in prokaryotic cells, while the larger 80S ribosome accommodates more complex eukaryotic protein synthesis processes.
• What role do the components of the 70S ribosome play in translation, particularly in relation to rRNA and protein interactions?
  • The components of the 70S ribosome play vital roles in translation by providing structural support and facilitating interactions between mRNA and tRNA. The rRNA within the small 30S subunit helps recognize the start codon on mRNA, while the large 50S subunit catalyzes peptide bond formation between amino acids. Proteins associated with these rRNA molecules assist in stabilizing the structure and ensuring proper function during protein synthesis, highlighting the critical interplay between rRNA and proteins within the ribosome.
• Evaluate how understanding the differences between prokaryotic and eukaryotic ribosomes could lead to advancements in antibiotic development.
  • Understanding the differences between prokaryotic 70S ribosomes and eukaryotic 80S ribosomes is crucial for antibiotic development because it allows scientists to design drugs that selectively target bacterial protein synthesis without affecting human cells. For instance, certain antibiotics bind specifically to the bacterial 70S ribosome, inhibiting its function and halting bacterial growth while leaving human cells unharmed due to their different ribosomal structure. This targeted approach not only enhances treatment efficacy but also helps reduce side effects associated with broader-spectrum antibiotics.

Related terms

80S Ribosome: A type of ribosome found in eukaryotic cells, consisting of a 60S large subunit and a 40S small subunit, which is larger than the prokaryotic 70S ribosome.

Ribosomal RNA (rRNA): The RNA component of a ribosome, crucial for its function in protein synthesis, with different types present in both prokaryotic and eukaryotic ribosomes.

Translation:

The process of synthesizing proteins from messenger RNA (mRNA) by ribosomes, involving decoding the mRNA sequence into a polypeptide chain.