• Question: Hello! Can RNA be on its own without being a part of mRNA or tRNA? if so, what is RNA alone?

    Asked by anon-244767 on 29 Apr 2020.
    • Photo: Alena Pance

      Alena Pance answered on 29 Apr 2020:

      What a wonderful question! this is one of the emerging fields in biological research.
      There are many types of RNA coded for in our genome that do not get translated into a protein. This is the main traditional role of RNA: transcribe the bit of DNA that codes for a protein, so that this RNA can go to the cytoplasm of the cell where the message can be translated into the effector molecule and this is where tRNAs come into the picture. Just to clarify, the things that cells do, the functions they perform, how they surviva and replicate is all part of the functions performed by the proteins each cell makes at specific moments in time.
      BUT we now know there are thousands of microRNAs, long non-coding RNAs, among others, that do not code for proteins but serve to control cellular function. As the human genome is better understood, we are finding more and more of these non-coding ‘regulatory’ RNAs that are quite happy to ‘float’ around the cell and tweak how things work here and there.

    • Photo: Leanne Milton-Harris

      Leanne Milton-Harris answered on 30 Apr 2020:

      The short answer is yes! RNA is a lot like DNA, with a couple of differences. Firstly, one of the bases changes, so instead of containing the base thymine (T), it has uracil (U) in its place. Secondly, there is a change to the sugar molecule. In DNA, you find deoxyribose but in RNA we have ribose – they’re the same sugar except for one extra OH group in ribose. All RNA has the same features, but we give different bits names because they do different jobs in the cell.

      Because of these differences, DNA and RNA have specific jobs. DNA is a lot more stable, that’s why it’s used to store all the information in your genome. It exists as a really long, double-stranded helix that gets folded up to fit in the nucleus. RNA is less stable, but really important for accessing all the information in the DNA. It acts as an intermediate, letting us copy the bits of DNA we need and transfer that message to make protein – that’s where the mRNA and tRNA come in.

      The more scientists study RNA, the more important they find it! As well as the mRNA and tRNA, there are lots of small RNA pieces (microRNAs) and longer pieces that control cellular processes. Plus we can use small pieces of RNA in the lab to artificially control gene expression, using things called siRNA (small interfering RNA) and shRNA (short hairpin RNA). People are still discovering new things about RNA now!

    • Photo: David Yuan

      David Yuan answered on 30 Apr 2020:

      The short answer is yes. An interesting example is that the Corona Virus, keeping us all at home, is using RNA on its own. It uses RNA as the way to store its all genetic information when it leaves our bodies if we caught the disease. When it gets into a cell, it releases this RNA molecule and then start tricking our bodies to make its children.
      In addition to mRNA, tRNA frequently mentioned, there are many other RNAs with special names such as rRNA, snRNA. These are just convenient names for people to refer to groups of similar RNA molecules. They all have times to be on its own. They all have times to be combined with proteins or lipids during their life cycles.

    • Photo: Angela Downie

      Angela Downie answered on 30 Apr 2020:

      RNA stands for RiboNucleic Acid, and it is one of many types of molecules that we have in our cells (and if you ask me it is one of the coolest ones!). As other people have said it is almost identical in structure to DNA except for a tiny -OH chemical group, but that small group makes a big difference (Fun fact: RNA came into existence before DNA!) The small change in structure, makes DNA much more stable than RNA which is why it is so good at storing genomic information. Basically, DNA is in charge of keeping your cells information safe, and this is it’s main and often only function. RNA, however has many, many jobs within our cells and the letters that you see in front of it such as m-RNA or t-RNA are indicating the job that it does. mRNA is the most common type of RNA and the m stands for messenger RNA. As its name says it is a messenger, carrying the information found in DNA from the saftey of the nucleus out onto the cell protein producing machinery. tRNA stands for transfer RNA and they are part of the cells machinery where they read the message carried by mRNAs and use it to build proteins, to do this they team up with even yet another type of RNA called ribosomal RNA, or rRNA which helps bring the mRNA and tRNA together. Aside from these three main types of RNA we now know there is a long list of jobs that RNA can do so we have created new names for them such such as miccro RNA (miRNA), picoRNA (piRNA), short interfering RNA (siRNA), long non-coding RNA (lncRNA), small nucleolar RNA (snoRNA) etc… And they all do different things! And we are still finding out what these things are! As we do, you will probably see more and more letters appear in front of RNA, telling just how many jobs this one molecule can do!

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