Don't write a general list of your interests. Discuss the specifics on what you want to get out of the internship. If you want to tie your interests in, that is great, but focus on your goals. Usually the point of an internship is to gain skills or knowledge.
Write the things you want to learn from an internship as your internship objectives. Objectives are a wider scope of goals where you acquire knowledge on a specific field with the allocated resources within a specific time frame.