Final answer:
RNA synthesis, or transcription, occurs in the nucleus by RNA polymerase II. However, before RNA can produce proteins, it must undergo processing steps such as splicing and post-processing modifications, including adding a 5' cap and poly-A tail.
Step-by-step explanation:
RNA synthesis, also known as transcription, occurs before protein formation. It takes place in the nucleus and is carried out by an enzyme called RNA polymerase II. However, before the RNA can be used to produce proteins, it undergoes several processing steps.
One important step is called splicing, where the pre-mRNA is modified to remove non-coding regions called introns and join together the coding regions called exons. Once the RNA has been spliced, it becomes mature mRNA that can be translated into protein.
Other post-processing modifications, such as adding a 5' cap and a poly-A tail to the mRNA, are also necessary for efficient translation.