Whether it’s Matthew McConaughey in A Time to Kill, Sandra Bullock in Speed, Edward Norton in Primal Fear or Ryan Gosling in The Believer, every so often there’s a feeling one gets watching a movie that the career of a young performer is about to explode into the stratosphere. The stand-alone or lasting quality of the film isn’t the most important thing, but rather the manner in which the actor or actress pops off the screen, and commands your attention in a variety of ways, large and small. A perceptive, engaging coming-of-age tale adapted from Lynn Barber’s memoir by About a Boy author Nick Hornby, An Education is just that sort of film for 24-year-old Carey Mulligan (below).

She stars as Jenny, an intelligent, headstrong, 16-year-old British girl itching to shake off the constraints of her suburban, all-girls-school upbringing circa 1961. Jenny swoons when she meets David (Peter Sarsgaard), a dapper guy twice her age who knows about art and wine, and has jet-setting pals, Danny (Dominic Cooper) and Helen (Rosamund Pike). Her friends are equally agog and her practically minded parents (Alfred Molina and Cara Seymour) surprisingly open to the courtship, so no matter the disapproval of her teacher (Olivia Williams), Jenny decides to celebrate her impending 17th birthday by losing her virginity with David.

The fact that An Education has to be described even to the degree above is somewhat regrettable, because the prescribed path of its narrative motivations are artfully obscured for a good bit of its running time, which actually benefits the movie. The more one experiences it wide-eyed and nakedly, like Jenny, the deeper the identification. There’s a fantastic exchange late in the film between Jenny and her headmistress (Emma Thompson) in which the young student eschews a glass-ceiling life of modulated expectation, instead making a case for stridency and a life lived through experience, no matter the pain: “Just an education isn’t good enough anymore — you have to tell us what it’s for,” she says, registering just the right blend of anger and exasperation.

While some of the film’s cross-purposes casting (notably Pike, who’s mostly traded previously in ice princess roles, but delivers quite winningly as the happily unaware Helen) work quite well, Sarsgaard doesn’t seem to fully embody David’s silver-tongued charisma. Of course, it’s ultimately not his show, so in the end it doesn’t much matter, or at least not to a degree that sinks the film. In her performance, Mulligan locates both the braininess and restless hormonal energy of an adolescent who’s blooming before most of her peers. Bearing witness to her education, in all its naiveté, brashness, passion and pain, is illuminating. (Sony Pictures Classics, R, 100 minutes)

Adam Goldberg wears a furrowed-brow scowl of perpetual distrust and discontent; even in screen romances he seems unhappy, or at least convinced that the world is basically a dreadful place. So in theory he could be the perfect guide for a piece like (Untitled), a loose-limbed comedy that casts a skeptical eye on the contemporary New York art scene, as seen by and experienced through a pair of quietly competitive brothers. In reality, though, Goldberg is let down by the material.

Josh (Eion Bailey) is a commercially successful painter, even though his work is sold discreetly to corporate clients out of a gallery’s back room. Self-important composer Adrian (Goldberg, above), meanwhile, fronts a performance art trio who peddle atonal, disharmonious works involving buckets, chains, duck calls and crumpled paper. When gallery owner Madeline (Marley Shelton) attends Adrian’s concert, she commissions a work from him and a weird quasi-love affair ensues, even though Josh had earlier introduced Madeline as his girlfriend.

Almost from the start, (Untitled) seems conflicted about what sort of agenda to pursue, or perspective to advance. Is it a satiric send-up of the modern art world, a wry debunking of avant-garde sensibility in general, or just a very specifically rendered comedy of upward social mobility? Where (Untitled) really drops the ball is in not getting into the brothers’ relationship in a more substantive way. With Madeline, there’s ostensibly a love triangle here, but director Jonathan Parker and his co-scripter, Catherine di Napoli, never plumb any deep conflict from it. Perhaps most damningly, Adrian embraces experimentation in the realm of music, yet has disdain for every other artist in the film, whom he regards as fraudulent, insincere, untalented or a sell-out. That’d be fine if the movie at least had Adrian self-justify his point-of-view, or argue about it with Josh, as they grapple with contrasting notions of success. But he doesn’t, so (Untitled) itself comes off as fuzzy and false.

Zak Orth quietly steals scenes as a collector (“a guy who did something with a computer and got rich,” as one character describes him) given a personality infusion by art, and Shelton gives an invested performance. True, too: there are bits and pieces of the movie — an inquisitive woodwind score, a few fun zingers, Madeline’s penchant for noisy clothes — that give it some punch. But the characters here don’t ring true, and a problematic ending only further sullies what comes across as a rich concept unconvincingly explored. (Samuel Goldwyn, 96 minutes, R)