Sections 3 and 4 of the MCAT represent half of your total score (118 questions combined out of 230). Section 3 tests Biological & Biochemical Foundations, while Section 4 evaluates Psychological, Social, & Biological Foundations of Behavior.
1. Section 3: Biological & Biochemical Foundations Breakdown
Section 3 (59 questions, 95 minutes) focuses on molecular genetics, organ systems, and metabolic processes:
| Subject | Approximate Weightage | High-Yield Concepts |
|---|---|---|
| Biology | 65% | Molecular Genetics, Cell Biology, Organ Systems (Renal, Nervous, Endocrine) |
| Biochemistry | 25% | Metabolic Pathways (Glycolysis, Krebs, ETC, Gluconeogenesis), Enzymes |
| General Chemistry | 5% | Solutions, Equilibrium in biological fluids |
| Organic Chemistry | 5% | Bio-organic molecules, Lipids, Carbohydrates, Nucleic Acids |
2. Section 4: Psychological, Social & Biological Foundations Breakdown
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Section 4 (59 questions, 95 minutes) tests how psychological, social, and biological factors influence human behavior and healthcare outcomes:
| Subject | Approximate Weightage | High-Yield Concepts |
|---|---|---|
| Psychology | 65% | Learning/Conditioning, Memory, Personality, Psychological Disorders, Sensation |
| Sociology | 30% | Social Stratification, Demographics, Social Institutions, Culture, Inequality |
| Biology | 5% | Brain Structure, Neurotransmitters, Endocrine control of behavior |
3. Top High-Yield Topics for Bio & Psych
Prioritize these core areas during your review:
Metabolic Pathways (Bio/Biochem)
Know inputs, outputs, rate-limiting enzymes, and cellular locations for Glycolysis, Pyruvate Dehydrogenase, CAC, ETC, Glycogenesis, and Beta-Oxidation.
Genetics & Molecular Biology
Master Central Dogma, Operons, PCR, Gel Electrophoresis, DNA Replication, Mendelian Inheritance, and Hardy-Weinberg Equilibrium.
Psychological Theories & Theorists
Study Freud's Psychosexual Stages, Erikson's Psychosocial Stages, Piaget's Cognitive Stages, Kohlberg's Moral Development, and Maslow's Hierarchy.
Experimental Sociology Concepts
Distinguish between Bystander Effect, Groupthink, Social Facilitation, Conformity vs Obedience, and Fundamental Attribution Error.
4. EduQuest Practice Hub & Diagnostic Coaching
Test your recall of biological pathways and psychological definitions using full-length practice tests at the EduQuest Mock Hub (`/mock_hub/`).
5. Frequently Asked Questions (FAQ)
Is Section 4 (Psych/Social) purely memory recall?
While term vocabulary is key, AAMC tests terms through complex experimental passages and research study scenarios.
How detailed do I need to know amino acids for Section 3?
Extremely detailed! You must know all 20 amino acids: 1-letter & 3-letter codes, side chain structures, pKa values, polarity, and charge at physiological pH.
Where can I take diagnostic practice tests for Bio & Psych?
At the EduQuest Practice Hub (`/mock_hub/`).
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