Transcription and Translation: Turning DNA Recipes into Proteins

DNA transcription occurs in the cell nucleus, where genetic information is stored.The process begins with a DNA double helix, consisting of two complementary strands held together by base pairs.The DNA double helix begins to unzip, separating the two strands to expose the template strand.RNA polymerase enzyme attaches to the DNA template strand and begins moving along it.As RNA polymerase moves, it assembles a complementary RNA strand, following specific base-pairing rules.In RNA, uracil replaces thymine when pairing with adenine. Cytosine and guanine continue to pair with each other.The resulting messenger RNA strand carries the genetic instructions that will be used to build proteins.After transcription, the pre-messenger RNA undergoes several important modifications in the nucleus.The first modifications involve adding protective structures: a five-prime cap at the beginning and a poly-A tail at the end.The pre-messenger RNA contains both coding regions called exons, shown in blue, and non-coding regions called introns, shown in red.A complex called the spliceosome removes the introns and joins the exons together.The result is a mature messenger RNA molecule, ready for transport to the cytoplasm.The mature messenger RNA then passes through nuclear pores in the nuclear membrane to reach the cytoplasm.In the cytoplasm, the messenger RNA will interact with ribosomes, which will read its genetic instructions to build proteins.In the cytoplasm, the large and small ribosome subunits come together around the messenger RNA.The ribosome reads the mRNA code in three-letter segments called codons. The first codon, AUG, is the start codon.When the ribosome reaches the stop codon UAA, the completed protein chain is released.The protein chain then folds into its final three-dimensional shape, ready to perform its specific function in the cell.And that's how cells transform genetic instructions into functional proteins!Thanks for learning about protein synthesis with Spark.E!