Ribosomes
Definition: a cellular structure composed of proteins and RNA at which new proteins are synthesized; can be either attached to the endoplasmic reticulum or free in the cytoplasm
Function: Ribosomes synthesize proteins with their catalytic ability. They are found freely in cytoplasm (to make soluble proteins) or attached to the rough ER (to make membrane proteins). They are also found inside chloroplasts and mitochondria. Polysomes consist of several ribosomes bound to an mRNA, and they make proteins simultaneously. A prokaryotic cell contains a few thousand ribosomes, and a eukaryotic cell contains a few million. Each Ribosome is made up of one small subunit and one large subunit, which contain different types of ribosomal RNA (rRNA) and proteins. Scientist named the different subunits 60-S (large) and 40-S (small). mRNA is created in the nucleus when a protein needs to be made, and following that is sent into the cell and the ribosomes. The two subunits come together and combine with the mRNA when it is time to undergo protein synthesis. The subunits lock onto the mRNA and start the protein synthesis.
The 60-S/ 40-S model works fine for eukaryotic cells. Although in Prokaryotic cells, ribosomes are made of 50-S and 30-S subunits. Scientists have used the difference in ribosome size to develop drugs that can kill prokaryotic microorganisms that cause disease. They do this by targeting the base sequences specific to the RNAs and proteins of bacterial ribosomes. This explains how antibiotics such as tetracycline and streptomycin inactivate bacterial ribosomes but not eukaryotic.
The 60-S/ 40-S model works fine for eukaryotic cells. Although in Prokaryotic cells, ribosomes are made of 50-S and 30-S subunits. Scientists have used the difference in ribosome size to develop drugs that can kill prokaryotic microorganisms that cause disease. They do this by targeting the base sequences specific to the RNAs and proteins of bacterial ribosomes. This explains how antibiotics such as tetracycline and streptomycin inactivate bacterial ribosomes but not eukaryotic.