MCAT EXAM AND PRACTICE EXAM NEWEST 2026/
2027 | MEDICAL COLLEGE ADMISSION TEST AAMC
EXAM PREP WITH COMPLETE REAL EXAM
QUESTIONS AND CORRECT VERIFIED ANSWERS/
ALREADY GRADED A+ (MOST RECENT!!)
Core Domains
• Biological and Biochemical Foundations of Living Systems*
• Chemical and Physical Foundations of Biological Systems*
• Psychological, Social, and Biological Foundations of Behavior*
• Critical Analysis and Reasoning Skills*
• Biochemistry and Molecular Biology*
• General and Organic Chemistry*
• Physics and Biophysics*
• Psychology and Sociology*
• Research Design and Statistical Reasoning*
• Scientific Inquiry and Reasoning Skills*
Introduction
This comprehensive assessment evaluates the knowledge and reasoning skills required for success on the
Medical College Admission Test. It measures mastery of foundational concepts in biology, biochemistry,
chemistry, physics, psychology, and sociology. The examination uses multiple-choice and passage-based
items that reflect the integrated, interdisciplinary nature of the MCAT. Emphasis is placed on scientific
inquiry, data interpretation, critical reasoning, and the application of knowledge to solve novel problems.
Candidates must demonstrate the ability to analyze experimental results, evaluate hypotheses, and
apply scientific principles to clinical and research scenarios.
SECTION ONE: QUESTIONS 1–100
Question 1
Which organelle is primarily responsible for synthesizing lipids and detoxifying drugs in liver cells?
A. Ribosome
B. Golgi apparatus
,C. Smooth endoplasmic reticulum
D. Lysosome
C. Smooth endoplasmic reticulum
RATIONALE: The smooth endoplasmic reticulum synthesizes lipids, phospholipids, and steroids and
detoxifies harmful metabolic byproducts, making it especially abundant in liver cells.
Question 2
Which type of enzyme catalyzes the transfer of phosphate groups from ATP to another molecule?
A. Ligase
B. Kinase
C. Hydrolase
D. Oxidoreductase
B. Kinase
RATIONALE: Kinases transfer phosphate groups, commonly from ATP to another molecule, a process
known as phosphorylation that regulates enzyme activity and signal transduction.
Question 3
The Michaelis constant (Km) represents which of the following?
A. The maximum velocity of an enzyme reaction
B. The rate of product formation
C. The substrate concentration at half-maximal velocity
D. The amount of enzyme present
C. The substrate concentration at half-maximal velocity
RATIONALE: Km indicates enzyme affinity for substrate; a lower Km means higher affinity. It is
defined as the substrate concentration at which the reaction velocity is half of Vmax.
Question 4
What molecule acts as the final electron acceptor in the electron transport chain?
A. NAD+
B. FAD
C. Oxygen
D. Carbon dioxide
C. Oxygen
, RATIONALE: Oxygen combines with electrons and hydrogen ions to form water, completing aerobic
respiration. Without oxygen, the electron transport chain halts.
Question 5
Which process directly produces ATP during glycolysis?
A. Oxidative phosphorylation
B. Substrate-level phosphorylation
C. Chemiosmosis
D. Beta oxidation
B. Substrate-level phosphorylation
RATIONALE: Glycolysis generates ATP via substrate-level phosphorylation, where a phosphate group
is transferred directly from a substrate to ADP without the involvement of the electron transport chain.
Question 6
A mutation in a gene's promoter region is most likely to affect which of the following?
A. The rate of transcription initiation
B. mRNA splicing
C. Protein folding
D. Ribosome binding
A. The rate of transcription initiation
RATIONALE: Promoter regions control transcription initiation by influencing RNA polymerase
binding. Mutations here typically alter the efficiency or timing of gene expression.
Question 7
Which amino acid can form disulfide bonds?
A. Tyrosine
B. Methionine
C. Cysteine
D. Serine
C. Cysteine
RATIONALE: Disulfide bridges form between thiol (-SH) groups of cysteine residues. These covalent
bonds are critical for stabilizing tertiary and quaternary protein structure.
, Question 8
Which of the following best describes the role of tRNA?
A. It catalyzes peptide bond formation.
B. It carries amino acids to the ribosome during translation.
C. It forms the ribosomal structure.
D. It transports mRNA out of the nucleus.
B. It carries amino acids to the ribosome during translation.
RATIONALE: Each tRNA molecule binds a specific amino acid and matches it to codons on mRNA
through complementary anticodon pairing, ensuring accurate protein synthesis.
Question 9
The main purpose of the Krebs cycle is to do which of the following?
A. Produce glucose
B. Generate high-energy electron carriers
C. Break down fatty acids
D. Synthesize proteins
B. Generate high-energy electron carriers
RATIONALE: The Krebs cycle generates NADH and FADH2 for ATP production through oxidative
phosphorylation. It also produces some GTP and carbon dioxide.
Question 10
During mitosis, sister chromatids separate during which phase?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
C. Anaphase
RATIONALE: In anaphase, the centromeres divide, and sister chromatids move to opposite poles of
the cell, ensuring each daughter cell receives a complete set of chromosomes.
Question 11
Which hormone increases blood calcium levels?
2027 | MEDICAL COLLEGE ADMISSION TEST AAMC
EXAM PREP WITH COMPLETE REAL EXAM
QUESTIONS AND CORRECT VERIFIED ANSWERS/
ALREADY GRADED A+ (MOST RECENT!!)
Core Domains
• Biological and Biochemical Foundations of Living Systems*
• Chemical and Physical Foundations of Biological Systems*
• Psychological, Social, and Biological Foundations of Behavior*
• Critical Analysis and Reasoning Skills*
• Biochemistry and Molecular Biology*
• General and Organic Chemistry*
• Physics and Biophysics*
• Psychology and Sociology*
• Research Design and Statistical Reasoning*
• Scientific Inquiry and Reasoning Skills*
Introduction
This comprehensive assessment evaluates the knowledge and reasoning skills required for success on the
Medical College Admission Test. It measures mastery of foundational concepts in biology, biochemistry,
chemistry, physics, psychology, and sociology. The examination uses multiple-choice and passage-based
items that reflect the integrated, interdisciplinary nature of the MCAT. Emphasis is placed on scientific
inquiry, data interpretation, critical reasoning, and the application of knowledge to solve novel problems.
Candidates must demonstrate the ability to analyze experimental results, evaluate hypotheses, and
apply scientific principles to clinical and research scenarios.
SECTION ONE: QUESTIONS 1–100
Question 1
Which organelle is primarily responsible for synthesizing lipids and detoxifying drugs in liver cells?
A. Ribosome
B. Golgi apparatus
,C. Smooth endoplasmic reticulum
D. Lysosome
C. Smooth endoplasmic reticulum
RATIONALE: The smooth endoplasmic reticulum synthesizes lipids, phospholipids, and steroids and
detoxifies harmful metabolic byproducts, making it especially abundant in liver cells.
Question 2
Which type of enzyme catalyzes the transfer of phosphate groups from ATP to another molecule?
A. Ligase
B. Kinase
C. Hydrolase
D. Oxidoreductase
B. Kinase
RATIONALE: Kinases transfer phosphate groups, commonly from ATP to another molecule, a process
known as phosphorylation that regulates enzyme activity and signal transduction.
Question 3
The Michaelis constant (Km) represents which of the following?
A. The maximum velocity of an enzyme reaction
B. The rate of product formation
C. The substrate concentration at half-maximal velocity
D. The amount of enzyme present
C. The substrate concentration at half-maximal velocity
RATIONALE: Km indicates enzyme affinity for substrate; a lower Km means higher affinity. It is
defined as the substrate concentration at which the reaction velocity is half of Vmax.
Question 4
What molecule acts as the final electron acceptor in the electron transport chain?
A. NAD+
B. FAD
C. Oxygen
D. Carbon dioxide
C. Oxygen
, RATIONALE: Oxygen combines with electrons and hydrogen ions to form water, completing aerobic
respiration. Without oxygen, the electron transport chain halts.
Question 5
Which process directly produces ATP during glycolysis?
A. Oxidative phosphorylation
B. Substrate-level phosphorylation
C. Chemiosmosis
D. Beta oxidation
B. Substrate-level phosphorylation
RATIONALE: Glycolysis generates ATP via substrate-level phosphorylation, where a phosphate group
is transferred directly from a substrate to ADP without the involvement of the electron transport chain.
Question 6
A mutation in a gene's promoter region is most likely to affect which of the following?
A. The rate of transcription initiation
B. mRNA splicing
C. Protein folding
D. Ribosome binding
A. The rate of transcription initiation
RATIONALE: Promoter regions control transcription initiation by influencing RNA polymerase
binding. Mutations here typically alter the efficiency or timing of gene expression.
Question 7
Which amino acid can form disulfide bonds?
A. Tyrosine
B. Methionine
C. Cysteine
D. Serine
C. Cysteine
RATIONALE: Disulfide bridges form between thiol (-SH) groups of cysteine residues. These covalent
bonds are critical for stabilizing tertiary and quaternary protein structure.
, Question 8
Which of the following best describes the role of tRNA?
A. It catalyzes peptide bond formation.
B. It carries amino acids to the ribosome during translation.
C. It forms the ribosomal structure.
D. It transports mRNA out of the nucleus.
B. It carries amino acids to the ribosome during translation.
RATIONALE: Each tRNA molecule binds a specific amino acid and matches it to codons on mRNA
through complementary anticodon pairing, ensuring accurate protein synthesis.
Question 9
The main purpose of the Krebs cycle is to do which of the following?
A. Produce glucose
B. Generate high-energy electron carriers
C. Break down fatty acids
D. Synthesize proteins
B. Generate high-energy electron carriers
RATIONALE: The Krebs cycle generates NADH and FADH2 for ATP production through oxidative
phosphorylation. It also produces some GTP and carbon dioxide.
Question 10
During mitosis, sister chromatids separate during which phase?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
C. Anaphase
RATIONALE: In anaphase, the centromeres divide, and sister chromatids move to opposite poles of
the cell, ensuring each daughter cell receives a complete set of chromosomes.
Question 11
Which hormone increases blood calcium levels?
