Answer:
Please note: on the answer below, Spanish Jews were not affected by the Spanish Inquisition at all. The only Jews that were affected were those who claimed to have converted to the Catholic religion. The Inquisition had no authority, whatsoever, over non-Catholics, and no interest in them. The investigation that is talked about below is about Christians who were following the Jewish faith NOT the Christian faith-but they were baptized Christians. Further, very few of these insincere Christians were actually sentenced to death, that is all propaganda by anti-Catholics which has been propagated in the last several centuries, NOT historical fact.
Since the purpose of the Spanish Inquisition was to investigate whether or not people living in Spain were sincere Catholics or not, anyone who was not a sincere catholic stood to be adversely affected. The Catholic Kings, (or Los Reyes Católicos), Ferdidand and Isabel, wanted Spain to be a wholly Christian nation, and in Europe at the time, that meant being a catholic. Soldiers and Inquisitors were sent to closely watch anyone who did not appear to follow normal catholic behavior and customs. Because Jews had their own religious rituals, it was not always easy for them to appear to behave as Catholics. They were watched closely as they tried to continue their normal religious routines in secret. If an Inquisitor caught a Jew observing religious customs that were not those of Catholicism and decided to prosecute, the Jew would be jailed and punished. The Inquisitor would sometimes use torture to attempt to make the Jew swear to be a sincere catholic and to follow catholic customs. If the Jew refused, they could be exported, along with their family. In some severe cases where Jews refused to convert to Catholicism and held to their Jewish customs, they were burned at the stake in a public ceremony.