How does DNA transcription and translation work?
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Your cells keep the DNA locked away in a vault that only a certain set of proteins get access to. These proteins are called transcription factors and their role is to unfold the DNA at a specific point. See, your DNA is neatly folded and cannot be read everywhere, it would take up too much space if just laying in its unfolded form. So these transcription factors scan over the DNA and open it so much that other proteins now can find their binding sites. This will initiate the production of a copy, which is chemically a bit different than the DNA. Mostly, the copy is produced to be used outside the vault, and it’s not as stable as DNA for a reason we’ll see later. Only if the copy is processed correctly, it is transported outside the vault where a machinery will catch it. This huge protein complex is called ribosome and is located close to the vault. The ribosome has a channel into which translators can enter: the translators recognize three consecutive base pairs on your copy, and carry the amino acid that is coded by this base pair triplet. The translators enter the channel and if they fit onto the triplet, the ribosome then moves the amino acid brought by the translators onto the growing chain of the protein that is built from the DNA copy. It’s important that the copy is not living for ages around the ribosomes, so that you keep a timely control. Once the ribosome is done, the protein is released and modified further. Then, the copy can bind a new empty ribosome and produce another protein.
Something that goes beyond your question: the ribosome actually plays a crucial role where your protein ends up: the ribosome is anchored at a facility close to the vault called endoplasmic reticulum, or ER. The ER and the ribosome will look at the first snippet of your growing protein chain and will decide if the protein is pulled into the ER or placed into the membrane of the ER. Like this, membrane proteins are grown right into the membrane, proteins that end up in the lumen of the cell are released into the watery inside of the ER. Like this the ER can traffick the proteins to their final location.
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