What are the three main steps involved in the processing of pre-mRNA in eukaryotic cells? Phosphorylation, elongation, initiation 5' capping, splicing, 3' polyadenylation Glycosylation, elongation, translocation Splicing, translocation, translation Degradation, phosphorylation, translocation

The three main steps involved in the processing of pre-mRNA in eukaryotic cells are 5' capping, splicing, and 3' polyadenylation.

1. 5' capping: This is the first modification that happens during pre-mRNA processing. The 5' end of the pre-mRNA molecule is modified by the addition of a cap, which is a specific type of nucleotide. This cap is important for the stability of the mRNA and its subsequent transport out of the nucleus and into the cytoplasm.

2. Splicing: This is the process by which introns, or non-coding regions, are removed from the pre-mRNA molecule. The remaining exons, or coding regions, are then joined together. This process is carried out by a complex of proteins and RNA molecules known as the spliceosome.

3. 3' polyadenylation: This is the final modification to the pre-mRNA molecule. A long chain of adenine nucleotides, known as the poly(A) tail, is added to the 3' end of the molecule. This tail is important for the stability of the mRNA and its transport from the nucleus to the cytoplasm, as well as for the initiation of protein synthesis.