Final answer:
The ribosome is responsible for translation, reading the code provided by mRNA to synthesize polypeptides. The spliceosome and RNA polymerase II function in processing pre-mRNA and transcription, respectively.
Step-by-step explanation:
The enzyme complex responsible for translation is the ribosome. The ribosome is not actually an enzyme but a complex of RNA and proteins critical for protein synthesis. During translation, the messenger molecule (mRNA) provides the code, which is read by the ribosome to synthesize polypeptides. In contrast, the spliceosome is the protein complex responsible for removing introns from pre-mRNA, and RNA polymerase II is the enzyme that transcribes genes into pre-mRNA in the nucleus.
It is important to note that translation occurs in the cytoplasm, where ribosomes are either free-floating or attached to the endoplasmic reticulum. The RNA components of ribosomes are synthesized in the nucleolus within the nucleus.