Ribosomes are important cell organelles. A ribosome is a large complex of RNA and protein. It does RNA translation, building proteins from amino acids using messenger RNA as a template. Ribosomes are found in all living cells.
A ribosome is a mixture of protein and RNA that starts its formation in the nucleolus of a cell. The nucleolus is found in the center of the nucleus. The nucleus is protected by the nuclear envelope, and lets things out through the nuclear pores.
The job of the ribosome is to make new proteins. It does this by moving along a strand of RNA and building a protein based on the code it reads. Making a protein this way is called translation. Ribosomes are usually found in the rough endoplasmic reticulum, but can also be found throughout the cytoplasm.