If you’ve ever watched the whodunnit TV series CSI you have probably heard of DNA (deoxyribonucleic acid). DNA is found in every cell of your body and has the grand title of “The Building Blocks of Life.” This is because it contains the genes that make you who you are. Everyone's DNA is unique and helps the good guys solve crimes.
RNA Carries Your Genetic Code to the Cells
DNA also writes the instructions for the body to produce all the proteins it needs to stay alive. However, Grisham and Horatio (or whichever CSI series you prefer) have probably not introduced you to DNA’s lesser-known helper, RNA (ribonucleic acid).Without this second type of nucleic acid, DNA could not perform its life-giving job.
You have RNA in every one of your billions of cells and your body needs it to function everyday. Without the much more humble RNA, DNA could not express it’s genetic code to tell your body what to do. Each gene contains a bar code for making a particular protein. RNA is needed to act as a bar code scanner to decipher what your genes are saying. Without it your body would not be able to read its own genetic code to make important proteins such as hormones and blood cells.
What is RNA Transcription?
DNA only hangs out in the round nucleus, the central “brain” of the cell and does step foot outside into the rest of the cell where everything else happens. Instead it sends hard-working RNA to take its message outside of the nucleus to the cytoplasm where proteins are manufactured. But first, DNA must copy or transcribe its code by making RNA. This is where RNA transcription comes in.
First an enzyme called RNA polymerase (enzymes always end in -ase) is used to unzip or unravel the DNA helix. Then base-match pairing is used to make a new strand of RNA. It contains the same building blocks that DNA is made of, except that uracil is used in RNA instead of thymine which is used to make DNA. Thymine is not found in RNA.
Unlike the double-stranded DNA helix, RNA is produced as a lonely, single strand. It is called messenger RNA (mRNA) because it carries the message out of the nucleus to the cell’s cytoplasm where everything except for DNA is contained. Here, the copied code on the mRNA is read and translated to synthesize protein with the help of two other types of RNA, transfer RNA (tRNA) and ribosomal RNA (rRNA).
Noreen Kassem - Noreen Kassem is a hospital doctor based in London, UK. She has extensive experience in clinical research and an undergraduate honors ...
