QUESTIONS WITH 100% VERIFIED SOLUTIONS Q&A
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1. Which biomolecule is primarily responsible for catalyzing
biochemical reactions in cells?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids
Rationale: Enzymes are proteins that act as biological catalysts
by lowering activation energy.
Correct Answer: C
2. The primary structure of a protein is determined by:
A. Hydrogen bonding
B. Amino acid sequence
C. Hydrophobic interactions
D. Disulfide bonding
Rationale: Primary structure refers to the linear sequence of
amino acids.
Correct Answer: B
,3. Which bond links amino acids together in proteins?
A. Glycosidic bond
B. Peptide bond
C. Ester bond
D. Phosphodiester bond
Rationale: Peptide bonds form between carboxyl and amino
groups of amino acids.
Correct Answer: B
4. Enzyme activity is most affected by changes in:
A. DNA sequence
B. Temperature and pH
C. Lipid concentration
D. Cell size
Rationale: Enzymes are sensitive to environmental conditions
affecting structure.
Correct Answer: B
5. The active site of an enzyme is where:
A. Inhibitors bind permanently
B. Substrate binds and reaction occurs
C. ATP is stored
D. DNA is transcribed
Rationale: The active site binds substrate molecules specifically.
Correct Answer: B
,6. Competitive inhibition occurs when:
A. Inhibitor binds away from active site
B. Substrate is permanently destroyed
C. Inhibitor competes with substrate for active site
D. Enzyme is denatured
Rationale: Competitive inhibitors resemble substrate and
compete for active site.
Correct Answer: C
7. Which molecule stores genetic information?
A. Lipids
B. DNA
C. Glucose
D. ATP
Rationale: DNA encodes genetic instructions in cells.
Correct Answer: B
8. RNA differs from DNA because RNA:
A. Contains thymine
B. Is double-stranded
C. Contains uracil
D. Has deoxyribose sugar
Rationale: RNA uses uracil instead of thymine and is usually
, single-stranded.
Correct Answer: C
9. The process of converting DNA to mRNA is called:
A. Translation
B. Replication
C. Transcription
D. Mutation
Rationale: Transcription synthesizes RNA from a DNA template.
Correct Answer: C
10. ATP primarily functions as:
A. Structural molecule
B. Genetic material
C. Energy currency of the cell
D. Enzyme inhibitor
Rationale: ATP stores and transfers energy for cellular
processes.
Correct Answer: C
11. Glycolysis occurs in the:
A. Mitochondria
B. Nucleus
C. Cytoplasm
D. Endoplasmic reticulum