Final answer:
The enzyme alpha likely refers to DNA polymerase III, which operates in the cell nucleus or cytoplasm, adding nucleotides in the 5' to 3' direction and having a 3' to 5' exonuclease activity for proofreading.
Step-by-step explanation:
The enzyme alpha referred to in the question is likely DNA polymerase III in prokaryotic DNA replication or a similar DNA polymerase in eukaryotes involved in DNA synthesis. The location of this enzyme would be within the cell nucleus for eukaryotes, and within the cytoplasm for prokaryotes, as they do not have a nucleus. Its primary function is to add nucleotides in the 5' to 3' direction, essential for the synthesis of new strands of DNA. In terms of 3' to 5' exonuclease activity, this refers to the ability of the enzyme to remove RNA primers and replace them with newly synthesized DNA, which is crucial for both the initiation and the proofreading aspects of DNA replication to ensure accuracy and repair potential errors.