This can only be answered correctly if you look at your own experiences, as this requires a very personal answer. However, I can give you an example that might help as inspiration.
I was once at a doctor's office and a woman was very stressed out because her daughter was sick. She was desperate to see a doctor and would not stop complaining, even though there were other people ahead of her. When the doctor finally came, he was Indian, and the woman began to ask for an American doctor who spoke English (even though the doctor spoke English perfectly).
This is an example of discrimination because the doctor is being treated in an unfair and unequal way because of his race. This takes precedence over his abilities and qualifications. This type of racial discrimination is one of the most common types of prejudices that we find in people. Although this is not a form of institutionalized racism, it can certainly have the effect of increasing such bad treatment in other contexts.