I teach in a journalism program, so I'm often answering this question from the opposite perspective, helping students make the transition from academic prose to journalistic writing. Here are what I see as the major differences:
Journalistic: Short, simple declarative sentences. Attention to length and rhythm. Active voice.
Academic: Longer sentences with clauses often necessary to get across more complicated ideas.
Journalistic: In news stories, a sentence or two long. Direct quotations get their own paragraphs. One-sentence transitions to change topics.
Academic: First sentence introduces the topic (topic sentence). This is followed by several sentences that explore the topic.
Journalistic: Attribution is included in the same sentence as the direct or indirect quotation (Smith said, she acknowledged), usually at the end of the sentence. Quotations are rarely longer than two sentences.
Academic: Source of information is always included in footnotes, endnotes or works cited page. In-text parenthetical citation or super-script notation. Source may or may not be included in the text itself. Longer quotations indented as a text block.
Journalistic: Several forms depending on the type of story. Hard news is usually written with a summary paragraph at the top and then information in order of decreasing importance (inverted pyramid). Feature and longer explanatory stories might start with a vignette or scene-setter. Text organized by topic or chronologically.
Academic: Five-paragraph essay or an extended version of the essay: Introduction and context, middle organized by topic, acknowledgement of counter-argument, conclusion.
Journalistic: Presentation of facts or explanations for a general audience. Opinions come from people quoted in the story, not the writer. Points of view from different perspectives.
Academic: Writers are making an argument for a particular point of view (hypothesis) and using evidence and logic to prove or disprove it. Counter-arguments acknowledged near the end of paper primarily to be argued against.
Hope that's what you were looking for.