100 High-Yield Practice Questions, Detailed
Solutions & Exam Strategies
,MCAT 2026 High-Yield Practice Set
Question 1: Biology
A researcher discovers a mutation that prevents ribosomes from attaching to mRNA.
What cellular process will be directly affected?
A. DNA replication
B. Transcription
C. Translation
D. Glycolysis
Answer
✅ C. Translation
Explanation
Ribosomes read mRNA and synthesize proteins. This process is called translation.
DNA replication copies DNA.
Transcription produces mRNA.
Glycolysis breaks down glucose.
Question 2: Biochemistry
An enzyme has a Km of 2 mM and a Vmax of 100 μmol/min.
At a substrate concentration equal to Km, what is the reaction rate?
A. 25 μmol/min
B. 50 μmol/min
C. 75 μmol/min
D. 100 μmol/min
Answer
✅ B. 50 μmol/min
,Explanation
Michaelis-Menten equation:
V=Vmax[S]Km+[S]V = \frac{V_{max}[S]}{K_m+[S]}V=Km+[S]Vmax[S]
When:
[S]=Km[S]=K_m[S]=Km
then:
V=Vmax2V=\frac{V_{max}}{2}V=2Vmax V=50V=50V=50
Question 3: General Chemistry
What is the pH of a solution with:
[H+]=1×10−4[H^+]=1\times10^{-4}[H+]=1×10−4
A. 2
B. 3
C. 4
D. 5
Answer
✅ C. 4
Explanation
pH=−log[H+]pH=-\log[H^+]pH=−log[H+] pH=−log(10−4)=4pH=-\log(10^{-
4})=4pH=−log(10−4)=4
Question 4: Physics
A 2 kg object accelerates at 3 m/s².
What is the net force?
A. 1.5 N
B. 5 N
C. 6 N
D. 9 N
Answer
, ✅ C. 6 N
Explanation
Newton's Second Law:
F=maF=maF=ma F=(2)(3)=6NF=(2)(3)=6NF=(2)(3)=6N
Question 5: Biology
Which organelle is primarily responsible for ATP production?
A. Nucleus
B. Lysosome
C. Golgi apparatus
D. Mitochondrion
Answer
✅ D. Mitochondrion
Explanation
The mitochondrion carries out oxidative phosphorylation and generates most ATP.
Question 6: Organic Chemistry
Which functional group is found in ketones?
A. –OH
B. –COOH
C. C=O within a carbon chain
D. –NH₂
Answer
✅ C. C=O within a carbon chain
Explanation
Ketones contain a carbonyl group located between two carbons.
Example:
CH₃–CO–CH₃
Solutions & Exam Strategies
,MCAT 2026 High-Yield Practice Set
Question 1: Biology
A researcher discovers a mutation that prevents ribosomes from attaching to mRNA.
What cellular process will be directly affected?
A. DNA replication
B. Transcription
C. Translation
D. Glycolysis
Answer
✅ C. Translation
Explanation
Ribosomes read mRNA and synthesize proteins. This process is called translation.
DNA replication copies DNA.
Transcription produces mRNA.
Glycolysis breaks down glucose.
Question 2: Biochemistry
An enzyme has a Km of 2 mM and a Vmax of 100 μmol/min.
At a substrate concentration equal to Km, what is the reaction rate?
A. 25 μmol/min
B. 50 μmol/min
C. 75 μmol/min
D. 100 μmol/min
Answer
✅ B. 50 μmol/min
,Explanation
Michaelis-Menten equation:
V=Vmax[S]Km+[S]V = \frac{V_{max}[S]}{K_m+[S]}V=Km+[S]Vmax[S]
When:
[S]=Km[S]=K_m[S]=Km
then:
V=Vmax2V=\frac{V_{max}}{2}V=2Vmax V=50V=50V=50
Question 3: General Chemistry
What is the pH of a solution with:
[H+]=1×10−4[H^+]=1\times10^{-4}[H+]=1×10−4
A. 2
B. 3
C. 4
D. 5
Answer
✅ C. 4
Explanation
pH=−log[H+]pH=-\log[H^+]pH=−log[H+] pH=−log(10−4)=4pH=-\log(10^{-
4})=4pH=−log(10−4)=4
Question 4: Physics
A 2 kg object accelerates at 3 m/s².
What is the net force?
A. 1.5 N
B. 5 N
C. 6 N
D. 9 N
Answer
, ✅ C. 6 N
Explanation
Newton's Second Law:
F=maF=maF=ma F=(2)(3)=6NF=(2)(3)=6NF=(2)(3)=6N
Question 5: Biology
Which organelle is primarily responsible for ATP production?
A. Nucleus
B. Lysosome
C. Golgi apparatus
D. Mitochondrion
Answer
✅ D. Mitochondrion
Explanation
The mitochondrion carries out oxidative phosphorylation and generates most ATP.
Question 6: Organic Chemistry
Which functional group is found in ketones?
A. –OH
B. –COOH
C. C=O within a carbon chain
D. –NH₂
Answer
✅ C. C=O within a carbon chain
Explanation
Ketones contain a carbonyl group located between two carbons.
Example:
CH₃–CO–CH₃
