Organic Chemistry: The Most Important Prerequisite?

Teacher's assistant calculating organic chemistry lab report grades.

Undergraduate course requirements for pre-medical students vary to some degree among U.S. medical schools. However, no matter what your major is, all schools require one year of biology, one year of physics, and two years of chemistry, to establish a firm foundation in the basic biological and physical sciences. The chemistry coursework includes a year of general or inorganic chemistry followed by a year of organic chemistry.

Organic chemistry – commonly termed as “Orgo” or “O-chem” by its students – has traditionally been the only advanced science course required by medical schools for admission and arguably the most difficult class that all applicants have in common. This reason alone explains why your performance in this course is often singled out by admission committees.

But, what is really so special about organic chemistry that’s made it become singled out in such a manner?

First, A Little History…

The term organic was first used by a Swedish scientist, Jons Berzelius, in the early nineteenth century to refer to substances isolated from living systems. At that time many scientists subscribed to the idea that a vital or life force, in some circles also referred to as “ether”, was necessary to produce organic compounds. Furthermore, it was believed that since life itself could not be explained or understood, neither could the chemistry of organic compounds.

Unfortunately, that last part is a view still held by many organic chemistry students today!

Since the time of the vital force theory, many organic materials have been synthesized in the laboratory. Organic chemistry is not only the chemistry of living systems; it is more broadly defined as the chemistry of carbon-based compounds.

Carbon is quite unique among the elements and it can covalently bond in a wide variety of ways leading to an almost infinite number of possible compounds. These carbon compounds form the basis for many scientific systems that have nothing to do with living systems such as petroleum, plastics and synthetic fibers. Still, because living systems are primarily composed of carbon compounds and water, any area of study concerned with plants, animals, or microorganisms requires an understanding of the principles of organic chemistry.

Parallels Between O-chem and Medicine

Truth is, even for research-oriented physicians the need to know reactions of aldehydes and ketones or even the structural characteristics of DNA is unnecessary. The importance of O-chem and the reason why medical schools feel it is an appropriate delineator or “weeder class” for admission extends far beyond the subject material alone.

What makes it so special, then?

The subject requires thought processes and analysis that is quite different from the other science courses required in a pre-medical curriculum. Furthermore, these thought processes closely parallel the type of analysis that is required to make a clinical diagnosis in medicine. The actual experimental information is quite different, of course, but the general problem-solving skills that are required are strikingly similar.

What O-chem ISN’T

Upon first entering into an organic class, many students are under the misconception that the discipline requires rote memorization of hundreds of unrelated properties and reactions. This mind set is often the downfall of otherwise successful pre-meds. This is not to say that a significant amount of memorization is not required. Organic chemistry does have a vocabulary all its own, and like learning any foreign language one needs to know the vocabulary before writing or speaking a coherent sentence. Just knowing the facts and regurgitating them back on exams is not the primary focus of the course.

What O-chem IS

The advent of sophisticated instrumental techniques in the 20th century have lead to a more thorough understanding of the underlying principles that contribute to why organic molecules act the way they do. If the reasons behind the behavior are understood most organic phenomena and reactions can be predicted instead of memorized. Thus the way that organic chemistry is taught has been changed drastically over the years and it is now introduced using a more unified mechanistic approach, emphasizing fundamental models instead of specific examples.

Not surprisingly, the field of medicine has undergone a similar metamorphosis over the years.

The amount of material has grown at an exponential rate and medical students are often overwhelmed by the sheer volume of information. Fortunately, the human mind has far greater abilities than use as a database. Computers can store and retrieve information quickly but the power to reason is mankind’s unique gift. The fundamental molecular level mechanisms of body processes and disease are much better understood today.

In many cases, this has allowed physicians to determine and treat the origins of the problem. The challenge lies with classifying the problem based on the collected symptomatology.

Problem-solving similarities

The parallels between O-chem and medicine are quite evident. Both disciplines necessitate an in-depth understanding of fundamental models which can be used to predict and diagnose. Both call for a careful analysis of collected data in order to classify and utilize the appropriate model. Often this classification is subtle and requires insight that only experience with similar problem-solving activities can provide.


Honestly, not all students have the ability to think and analyze in the fashion that Orgo requires. That being said, it shouldn’t stop anyone from becoming a doctor either.

Few disciplines require this same type of complex conditional thought processing and organic chemistry is usually the first time this skill is thoroughly tested. So, it makes perfect sense that so many students find it to be such a challenge. But therein lies the real reason why organic chemistry is such an important delineator for medical school admission.

Understanding the concepts behind carbon-based chemistry may help you get a better grasp of the human body’s inner workings. However, it is the training of the mind to analyze, classify and predict that encompasses why O-chem is an important precursor to the study of medicine.

This is what makes organic chemistry a notorious, yet necessary requirement for admission to medical school and other health profession programs.

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