What’s Tested on the MCAT: Biology & Biochemistry
The Biological and Biochemical Foundations of Living Systems section of the MCAT, often called the MCAT Biology or MCAT Bio/Biochem section for short, requires you to solve problems based on knowledge of biological and biochemical concepts combined with Scientific Inquiry and Reasoning Skills (SIRS). The content on this section of the test also includes some general chemistry and organic chemistry.
However, you should keep in mind that the MCAT requires more than just an understanding of science content. The MCAT is primarily a test of critical reasoning skills. Knowing how to use biology and biochemistry information to interpret and solve more difficult problems is the key to a great MCAT score.
TABLE OF CONTENTS:
- MCAT Biology & Biochemistry: Overview
- MCAT Biology & Biochemistry: Disciplines
- MCAT Biology & Biochemistry: Foundational Concepts
- MCAT Biology & Biochemistry: Critical Reasoning (SIRS)
- MCAT Biology & Biochemistry: Structure of the Section
- MCAT Biology & Biochemistry: Section Scoring
MCAT Biology & Biochemistry: Overview
The biological and biochemical foundations of living systems section is the third section on the MCAT and follows a thirty-minute lunch break.
| MCAT Section | Number of Questions | Time Limit | Section Score Range |
| Biological and Biochemical Foundations of Living Systems | 59 total (10 passages, 44 passage-based questions, 15 discrete questions) | 95 minutes | 118-132 |
Exam content in the Bio/Biochem section will draw from biology, biochemistry, and chemistry disciplines, Foundational Concepts #1-3, and Scientific Reasoning and Inquiry Skills #1-4. Each type of exam content is explained in detail below.
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MCAT Biology & Biochemistry: Disciplines
The undergraduate courses that are reflected in the Bio/Biochem section of the MCAT are:
- Introductory Biology (65%)
- First-semester Biochemistry (25%)
- Introductory General Chemistry (5%)
- Introductory Organic Chemistry (5%)
Biology Subjects to Study for the MCAT
In order to study effectively for the MCAT Biological and Biochemical Foundations of Living Systems section, you should thoroughly understand these biology topics:
- Cardiovascular Systems
- Cells
- Digestive Systems
- Embryogenesis and Development
- Endocrine Systems
- Excretory Systems
- Genetics and Evolution
- Immune Systems
- Nervous Systems
- Musculoskeletal Systems
- Reproduction
- Respiratory Systems
Biochemistry Subjects to Study for the MCAT
In order to study effectively for the MCAT Biological and Biochemical Foundations of Living Systems section, you should thoroughly understand these biochemistry topics:
- Amino Acids, Peptides, and Proteins
- Biological membranes
- Carbohydrate metabolism
- Carbohydrate structure
- DNA and RNA
- Enzymes
- Lipids and lipid metabolism
- Non-enzymatic proteins
- Regulation of metabolism
You’ll also need to be familiar with chemistry topics. Visit our guide to what’s tested on the Chemical and Physical Foundations of Biological Systems section of the MCAT to learn more.
MCAT Biology & Biochemistry: Foundational Concepts
The AAMC has described the topics within the Biological and Biochemical Foundations of Living Systems section of the MCAT. These topics are subdivided into three Foundational Concepts, each of which has several sub-categories.
Foundational Concept #1: Structure and Function of Biomolecules
This foundational concept is about biomolecules and how different functions of the cell can support health or lead to disease. The content tested in this foundational concept comprise 55% of the questions in the Bio/Biochem section. This topic is further subdivided into four categories:
- Structure and function of proteins and their constituent amino acids
- Transmission of genetic information from the gene to the protein
- Transmission of heritable information from generation to generation and the processes that increase genetic diversity
- Principles of bioenergetics and fuel molecule metabolism
Foundational Concept #2: Interaction of Highly-Organized Molecules, Cells, and Organs
This foundational concept is about the interaction of highly-organized assemblies of molecules, cells and organs to carry out the functions of living organisms. The content tested in this foundational concept comprise 20% of the questions in the Bio/Biochem section. This topic is further subdivided into three categories:
- Assemblies of molecules, cells and groups of cells within single cellular and multicellular organisms
- The structure, growth, physiology, and genetics of prokaryotes and viruses
- Processes of cell division, differentiation and specialization
Foundational Concept #3: Integrated Functioning of Complex Systems of Tissues and Organs
This foundational concept is about the integrated functioning of complex systems of tissues and organs to sense internal and external environments of multicellular organisms and to maintain a stable internal environment within an ever changing external environment. The content tested in this foundational concept comprise 25% of the questions in the Bio/Biochem section. This is further subdivided into two subcategories:
- Structure and function of the nervous and endocrine systems and ways in which these systems coordinate organ systems
- Structure and integrative function of the main organ systems
MCAT Biology & Biochemistry: Critical Reasoning (SIRS)
The MCAT exam will assess your proficiency in four scientific inquiry and reasoning skills, or SIRS, that are essential for physicians to excel and make progress in their fields. These four skills will be evaluated in three exam sections, including Bio/Biochem.
MCAT Biology & Biochemistry: Structure of the Section
In this section, the MCAT will present you with ten passages on biology and biochemistry topics, and ask four to six questions about each passage. The questions will address the four SIRS listed above, although not every passage will require you to use each skill. You will also be presented with 15 discrete questions that are not associated with passages. These will also be designed to test both your science knowledge and application of that knowledge based on these four skills.
MCAT Biology & Biochemistry: Section Scoring
The Bio/Biochem section of the MCAT is scored on a scale of 118-132, with the median score of all test-takers set to be 125. A given scaled score does not correspond to any specific number of right or wrong questions. According to the AAMC, “The MCAT exam is not graded on a curve. Instead, the MCAT exam is scaled and equated so that scores have the same meaning, no matter when you test or who tests at the same time you did.” The score for this section of the test is combined with the other three sections to provide your overall MCAT score which ranges from 472 to 528.
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Written by Kaplan experts, reviewed by Aeri Kim and Logan Emlet. Aeri Kim has been teaching MCAT prep at Kaplan for over eight years and also works on the MCAT content development team, helping optimize our courses to better suit student needs in real-time. She holds a BS in Biological Sciences as well as a PhD in Structural Biochemistry. Logan Emlet serves as an MCAT Product Manager at Kaplan North America. Since beginning his journey with Kaplan in 2013 as a teacher, he has guided thousands of students through the complexities of the MCAT.
