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4. Cells And Tissues eLearn.Punjab
Ribosomes
Ribosomes are tiny granular structures that are either floating freely in cytoplasm or are bound
to endoplasmic reticulum (ER). Each ribosome is made up of almost equal amounts of proteins
and ribosomal RNA (rRNA). Ribosomes are not bound by membranes and so are also found in
prokaryotes. Eukaryotic ribosomes are slightly larger than prokaryotic ones.
Ribosomes are the sites of protein synthesis. Protein synthesis is extremely important to cells, and
so large numbers of ribosomes are found throughout cells. When a ribosome is not working, it
disassembles into two smaller units (Figure 4.12) .
Figure 4.12: Ribosome
Animation 4.4: Ribosomes V: 1.1
Source and Credit: Nature
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