what do rRNA do? (what is their role)?

Answer 1

While most of the things a cell makes are proteins, there are a few things that are made directly out of RNA itself. In these cases, the RNA folds up and performs functions inside the cell in much the same way as a protein might, but without an extra step in the middle to make the protein. Because of this and the fact that these structures often are almost identical in almost all life we know of, many scientists think that these are some of the oldest preserved coding sequences that still exist.

rRNA specifically is what ribosomes are made of. Once they are transcribed, they fold up, are connected together, and they're ready to make actual proteins. Handy. Most ribosomes are made up of two different rRNA subunits, and most cells have dozens of copies of the genes that produce these subunits. If a cell has no rRNA, all its mRNA is useless and it isn't going to have any proteins it didn't inherit from its parents.

Another example of an RNA-only cell component is tRNA. You may note that tRNA is ALSO used in making proteins along with the rRNA. Probably not a coincidence.

Answer 2

rRNA means ribosomal RNA. This is a polymer of bases (a mix of A,U,C,G) that is coiled up onto itself and this "blob", if you will, makes up two ribosomal subunits, a larger one and a smaller one. rRNA is interspersed with a few proteins that help this rRNA "blob" to maintain its shape. rRNA, like many other types of RNAs is formed in the nucleolus (a small area in the nucleus of the cell) and then it is shipped outside the nucleus where it can perform its specific function. rRNA is responsible for processing the mRNA (messenger RNA) molecule in order to produce the proteins needed by the cell. This process is called TRANSLATION and to visualize this process you could picture a conveyer belt (mRNA) passing between two rollers (the ribosomal subunits). Through this process the ribosomal RNA "reads" the messages encoded in the bases of the mRNA and translates every ensemble of three letters (the ensemble is called a codon, for example one codon is AUG) into a specific amino acid. Also the rRNA joins every amino acid to each other to form a protein (a protein is sort of like a pearl necklace where each pearl is an amino acid; the whole necklace is the protein). You might be asking "where does mRNA get those instructions that are encoded in it?" mRNA copies the info from DNA in a process called TRANSCRIPTION. So, mRNA is sort of like a single-stranded carbon copy of the DNA molecule with the only difference that mRNA has the base Uracil instead of the base Thymine found in DNA. The genes in the DNA are responsible for dictating what kind of protein is needed by the cell at any given time in an organism's life.

Answer 3

Stands for ribosomal RNA. responsible for ribosome production

Answer 4

It's a sub-part of DNA and genius down there is right to.