When you say "Arabic" I am assuming that you mean Arabic script and not the language as the Ottoman Empire never adopted a single language for all official purposes. Instead, various languages were used for different situations.

If you are referring to the language Persian would be used for matters of science and art as it had been since the time of the Seljuks, Arabic (Classic Arabic) would be used for matters of religion, Turkish would be spoken for day-to-day matters or when addressing commoners. But on top of all that other languages like Hebrew, Latin and later French would be used in courtly matters aswell (Mehmed II spoke 5 languages). After the 15'th century this combination of languages would lead to a "Ottoman Turkish" being formed which generally used Arabic Script and resembled all of the aforementioned languages to an extent.

When it comes to outside the court tens of languages and their variations were spoken, including Ottoman Turkish written in the Latin script.

When it comes to the relationship between Turks and Arabic the sources are less clear but Divan-ı Lügat written in the 1080's was the oldest known Turkish-Arabic dictionary.