Since you don't understand, quotes denote emphasis or specificity, not emotion.
Actually quotes denote quotations. When used casually around an individual word or short phrase they generally indicate that the writer is emphasizing that these are someone else's words, and that the writer would have chosen a different description. As in: These people are described as "teens" but are probably not only/mostly teenagers. That may not be what you meant, but it's how that text will be read.
If you just want emphasis you might consider using bold or italics rather than quotes.