The essay section is out and sociology is in, and test-takers will need to be as familiar with psychology terms, such as “reciprocal determinism,” as they are with organic chemistry.

The 8,200 aspiring doctors expected to take the Medical College Admission Test, or MCAT, this week will find a very different exam than their predecessors took.

The new test, the first major revision in 25 years, is longer (by 3 hours), broader (covering four more subjects), and more interdisciplinary than past versions. Throughout, students will need to demonstrate not just what they know, but how well they can apply it, according to the Association of American Medical Colleges, which develops and administers the MCAT.

The changes are designed in part to mirror the evolution of health-care delivery and even the nature of illness, the AAMC says.

“One hundred years ago, all you really needed to know was the science. We were all looking for the magic bullet that would cure disease,” said Catherine Lucey, vice dean of the University of California, San Francisco, School of Medicine and a member of the MCAT review committee. “Now we have problems like obesity and diabetes that require doctors to form therapeutic alliances with patients and convince them to change their lifestyle.”