MCAT Exam Syllabus Biology Complete Guide 2026: Bio/Biochem Topics, Weightage, and 2026 Test Dates

MCAT Exam

If you’re targeting medical school admissions in 2026, “biology” on the MCAT isn’t just memorizing chapters—it’s applying biology + biochemistry to real experimental passages under time pressure. The AAMC calls this section Biological and Biochemical Foundations of Living Systems (Bio/Biochem), and it’s one of the most score-defining parts of the exam.

This guide breaks down the MCAT exam syllabus biology for 2026 with the official content categories, topic buckets, weightage, skills tested, and a table of real 2026 MCAT dates + score release dates from AAMC.

Why the MCAT “Biology Syllabus” is Really Bio + Biochem + Reasoning

The Biological and Biochemical Foundations of Living Systems section is designed to test:

• Intro biology + biochemistry (plus small portions of general & organic chemistry)

• Cellular/molecular biology at typical intro sequence level

• Research methods + statistics applied to natural sciences

• Your ability to reason through passages using scientific inquiry skills

Bio/Biochem section format (AAMC)

• 59 questions

• 95 minutes

• Mix of passage-based + discrete questions

MCAT Exam Syllabus Biology 2026: Official Weightage (What Dominates This Section)

AAMC’s official framework shows these approximate discipline weights in the Bio/Biochem section:

• Introductory Biology: 65%

• First-semester Biochemistry: 25%

• General Chemistry: 5%

• Organic Chemistry: 5% 

Foundational Concept weightage (high-yield map)

• Foundational Concept 1: 55%

• Foundational Concept 2: 20%

• Foundational Concept 3: 25% 

Skills weightage (how questions are written)

AAMC also indicates Bio/Biochem questions are distributed across scientific reasoning skills approximately as:

• Skill 1: 35%

• Skill 2: 45%

• Skill 3: 10%

• Skill 4: 10% 

Important note (transparency): I attempted to use the tool-required PDF screenshot function for the AAMC Bio/Biochem PDF, but it returned a validation error in this environment. I used the AAMC PDF’s extracted text from the official download instead.

What AAMC Actually Tests: The 4 Scientific Inquiry & Reasoning Skills (SIRS)

Even if your biology content is strong, your score jumps when you practice these AAMC skills:

1. Knowledge of Scientific Concepts and Principles

2. Scientific Reasoning and Problem-Solving

3. Reasoning About the Design and Execution of Research

4. Data-Based and Statistical Reasoning 

In simple terms: you must read experiments, interpret graphs, spot controls/confounders, and predict outcomes—using biology/biochem knowledge as a tool.

MCAT Biology Syllabus 2026 (AAMC Framework): Foundational Concepts + Content Categories

AAMC structures the Bio/Biochem section into 3 foundational concepts, each with official content categories.

Foundational Concept 1 (≈55%): Biomolecules & Processes That Sustain Life

Content Categories

• 1A. Structure and function of proteins and amino acids

• 1B. From gene to protein (genetic information flow)

• 1C. Heritable information, inheritance, genetic diversity

• 1D. Bioenergetics & fuel metabolism 

What this looks like in questions (common MCAT patterns)

• Enzyme kinetics, inhibition graphs, protein structure changes (pH/temperature/mutations)

• DNA replication/repair, transcription/translation regulation, operons

• Mendelian + non-Mendelian genetics, Hardy–Weinberg, gene linkage, recombination

• Glycolysis/TCA/ETC integration, fed vs fasted states, metabolic regulation

Foundational Concept 2 (≈20%): Cells, Membranes, Division, Microbes

Content Categories

• 2A. Assemblies of molecules/cells (cell structure, membranes, organelles)

• 2B. Prokaryotes and viruses (structure, growth, genetics)

• 2C. Cell division, differentiation, specialization 

High-yield MCAT patterns

• Membrane transport (channels vs carriers), signaling pathways, cell junctions

• Viral life cycles, bacterial genetics (transformation/transduction/conjugation), antibiotics basics

• Mitosis vs meiosis, checkpoints, stem cell differentiation, cancer-like passage logic

Foundational Concept 3 (≈25%): Organ Systems, Homeostasis, Neuroendocrine Control

Content Categories

• 3A. Nervous & endocrine systems; coordination across systems

• 3B. Structure and integrative functions of main organ systems 

High-yield MCAT patterns

• Neuron signaling, neurotransmitters, endocrine feedback loops

• Cardiovascular/respiratory integration, renal filtration/osmoregulation, immune response basics

• Homeostasis passages with changing variables (CO₂, pH, glucose, blood pressure)

Practical “Syllabus-to-Study” Breakdown (Topic Checklist You Can Actually Use)

Below is a user-friendly checklist aligned to AAMC’s structure (so your prep stays exam-relevant):

A) Biochemistry core (big impact because it’s tested heavily in passages)

• Amino acids, protein structure, enzyme function

• Carbohydrates, lipids, nucleotides

• Metabolism: glycolysis, gluconeogenesis, glycogen, TCA, ETC, β-oxidation

• Regulation: hormones, allosteric control, energy states

• Lab techniques: SDS-PAGE, Western blot, ELISA, PCR basics (often embedded in passages)

B) Molecular & Cellular biology (passage-heavy)

• Membranes, transport, organelles

• Cell signaling (receptors, second messengers)

• DNA replication/repair, transcription, translation, gene regulation

• Cell cycle, apoptosis, differentiation

C) Genetics & Evolution

• Mendelian genetics + probability

• Linkage, recombination, inheritance patterns

• Population genetics and selection logic (when included)

D) Human physiology & systems (homeostasis-driven reasoning)

• Nervous & endocrine integration

• Cardiovascular + respiratory gas exchange

• Kidney function, osmolarity, acid-base balance

• Immune principles (often experimental)

2026 MCAT Dates You Should Plan Around (Real AAMC Calendar + Score Releases)

AAMC publishes official U.S. test dates, scheduling deadlines, and score releases. Scores are released by 5:00 p.m. ET on the listed score release dates, and deadlines are 11:59 p.m. local test center time.

Table: 2026 MCAT U.S. Test Dates + Score Release Dates (AAMC)

Month	2026 Test Date(s)	Score Release Date(s)
January	Jan 9, 10, 15, 23	Feb 10, 17, 24
February	Feb 13	Mar 17
March	Mar 7, 20	Apr 7, 21
April	Apr 10, 11, 24, 25	May 12, 27
May	May 2, 8, 9, 14, 22, 30	Jun 2, 9, 16, 23, 30
June	Jun 12, 13, 26, 27	Jul 14, 28
July	Jul 11, 24, 31	Aug 11, 25, Sep 2
August	Aug 15, 21, 22	Sep 15, 22
September	Sep 3, 4, 11, 12	Oct 6, 13

Source: AAMC U.S. 2026 MCAT Calendar

2026 MCAT Registration Fees (So You Budget Correctly)

According to AAMC’s official fee table for 2026:

• Standard registration: $355

• Fee Assistance Program registration: $145

• International fee add-on: $130 (if testing outside U.S./Canada/U.S. territories; non-refundable)

Also: 10 days before the exam is the last day to schedule/reschedule/cancel (per AAMC policy).

How to Prepare Bio/Biochem Like the MCAT Writes It (Not Like a Textbook)

1) Train passage interpretation daily

Bio/Biochem is loaded with experiments. Practice reading:

• hypothesis → method → results → conclusion

• “What would happen if…” variable-change questions

• graph/table interpretation (Skill 4)

  
  

2) Convert syllabus into “AAMC-style prompts”

Instead of “study glycolysis,” practice:

• “Predict ATP changes if enzyme X is inhibited”

• “Which mutation disrupts folding?”

• “Which control validates the conclusion?”

  
  

3) Use the concept-weightage to prioritize

A smart order for most students:

1. Foundational Concept 1 (biochem + molecular biology)

2. Foundational Concept 3 (systems + homeostasis reasoning)

3. Foundational Concept 2 (cells + microbes + division)

FAQ (2026)

1) What is included in the MCAT exam syllabus biology for 2026?

The MCAT exam syllabus biology (2026) primarily refers to AAMC’s Biological and Biochemical Foundations of Living Systems section, covering biomolecules, genetics, cells, organ systems, and homeostasis through three foundational concepts and their content categories (1A–1D, 2A–2C, 3A–3B). It’s tested through passage-based scientific reasoning, not rote memorization.

2) How many questions are in the MCAT Bio/Biochem section?

There are 59 questions in 95 minutes, combining passage-based and discrete items.

3) What topics are most important for Bio/Biochem?

AAMC places the biggest emphasis on Foundational Concept 1 (~55%), which includes proteins/enzymes, gene-to-protein, inheritance/genetic diversity, and metabolism/bioenergetics.

4) Are research methods and statistics part of “biology” on MCAT?

Yes. The section explicitly requires research methods and statistical reasoning applied to natural sciences, and it’s built into the scientific inquiry skills tested.

5) Where can I verify the official 2026 test dates and score releases?

Use AAMC’s official 2026 U.S. MCAT calendar, which lists test dates, deadlines, and score release dates.

CTA: Next Steps (Official Resources + Smart Actions)

1. Confirm your target test date + score release date using the official AAMC 2026 calendar.

2. Budget correctly using the official AAMC 2026 scheduling fees (registration/reschedule/cancel rules).

3. Start your prep using AAMC’s MCAT Official Prep Hub (official practice is the closest to real exam style).

4. If you’re registering soon, use AAMC’s official registration pages and policies (including the required “MCAT Essentials” guidance).