Semmelweis University Medicine Biology Entrance Examination 2026/2027 Verified Answers by Expert
Semmelweis University Medicine Biology Entrance Examination 2026/2027
Questions and Answers - Verified by Expert
Semmelweis University Faculty of Medicine | 100 Questions | Aligned with Official Admission Requirements
Section 1: Biochemistry and Molecules of Life
Questions 1-15
Q1: A biology student is analyzing two monosaccharide molecules that have been joined together. The reaction consumed
one water molecule during the formation of the bond. What type of chemical reaction occurred, and what type of bond was
formed between the two monosaccharides?
A. Hydrolysis reaction forming a peptide bond
B. Condensation reaction forming a glycosidic bond [CORRECT]
C. Oxidation reaction forming an ester bond
D. Reduction reaction forming a hydrogen bond
Correct Answer: B
Rationale: When two monosaccharides join, a condensation (dehydration synthesis) reaction occurs in which one molecule of water is
removed. The bond formed between the two sugar molecules is called a glycosidic bond. Hydrolysis is the reverse process that breaks
glycosidic bonds. Peptide bonds form between amino acids, not monosaccharides. Ester bonds form between fatty acids and glycerol in
triglyceride synthesis.
Q2: Which of the following polysaccharides functions as a structural component in plant cell walls rather than as an energy
storage molecule?
A. Glycogen
B. Starch
C. Cellulose [CORRECT]
D. Sucrose
Correct Answer: C
Rationale: Cellulose is a structural polysaccharide composed of beta-glucose monomers linked by beta-1,4-glycosidic bonds, making it
insoluble in water and ideal for forming rigid plant cell walls. Glycogen and starch are energy storage polysaccharides in animals and plants
respectively, composed of alpha-glucose. Sucrose is a disaccharide, not a polysaccharide, and serves as a transport sugar in plants.
Q3: A researcher is comparing saturated and unsaturated fatty acids. She observes that one fatty acid has no double bonds in
its hydrocarbon chain while another has two double bonds with hydrogen atoms on the same side. Which statement correctly
describes these two fatty acids?
A. The first is cis-unsaturated; the second is trans-saturated
B. The first is saturated; the second is cis-unsaturated [CORRECT]
C. Both are unsaturated but differ only in chain length
D. The first is trans-unsaturated; the second is saturated
Correct Answer: B
Rationale: Saturated fatty acids contain no carbon-carbon double bonds in their hydrocarbon chains, with each carbon fully bonded to
hydrogen atoms. Unsaturated fatty acids have one or more double bonds; when the hydrogen atoms attached to the double-bonded carbons
are on the same side, the isomer is designated as cis. Trans isomers have hydrogen atoms on opposite sides of the double bond. The
description clearly distinguishes a saturated fatty acid from a cis-unsaturated one.
Q4: Triglycerides are formed through the condensation of one glycerol molecule and three fatty acid molecules. What type
of chemical bond is formed between the glycerol and each fatty acid during this process?
Page 1
, A. Glycosidic bond
B. Peptide bond
C. Ester bond [CORRECT]
D. Phosphodiester bond
Correct Answer: C
Rationale: In triglyceride formation, each fatty acid undergoes a condensation reaction with the hydroxyl groups of glycerol, forming three
ester bonds (also called ester linkages) and releasing three water molecules. Glycosidic bonds form between monosaccharides. Peptide bonds
form between amino acids in protein synthesis. Phosphodiester bonds connect nucleotides in DNA and RNA strands.
Q5: A student is studying the properties of water that make it essential for biological systems. Which property of water is
most directly responsible for its ability to act as a solvent for many ionic and polar substances?
A. High specific heat capacity
B. Cohesion and adhesion
C. Polarity and hydrogen bonding [CORRECT]
D. High heat of vaporization
Correct Answer: C
Rationale: Water is a polar molecule with a partial negative charge near the oxygen atom and partial positive charges near the hydrogen
atoms. This polarity, combined with the ability to form hydrogen bonds, allows water to dissolve ionic and polar substances effectively. While
water high specific heat capacity, cohesion, and heat of vaporization are all biologically important properties, solvent capability is most
directly attributable to its molecular polarity and hydrogen bonding capacity.
Q6: A hydrogen bond can form between a hydrogen atom covalently bonded to which of the following elements and
another electronegative atom?
A. Carbon (C)
B. Nitrogen (N), Oxygen (O), or Fluorine (F) [CORRECT]
C. Sulfur (S)
D. Phosphorus (P)
Correct Answer: B
Rationale: Hydrogen bonds are a specific type of intermolecular attractive force that occurs when a hydrogen atom is covalently bonded to a
highly electronegative atom (nitrogen, oxygen, or fluorine) and is attracted to another electronegative atom nearby. The large
electronegativity difference creates a strong dipole, allowing the partially positive hydrogen to interact with lone pairs on adjacent
electronegative atoms. Carbon, sulfur, and phosphorus are not sufficiently electronegative to participate in hydrogen bonding.
Q7: In a laboratory experiment, a polysaccharide is treated with an enzyme that breaks the glycosidic bonds between
glucose monomers. This reaction consumes water molecules to break each bond. What is the correct term for this type of
reaction?
A. Condensation
B. Hydrolysis [CORRECT]
C. Dehydration synthesis
D. Oxidation
Correct Answer: B
Rationale: Hydrolysis is the chemical reaction that breaks bonds by the addition of a water molecule, essentially the reverse of condensation
(dehydration synthesis). In this case, water is consumed to cleave the glycosidic bonds holding the glucose monomers together in the
polysaccharide. Condensation removes water to form bonds. Dehydration synthesis is another name for condensation. Oxidation involves
electron transfer, not water-mediated bond cleavage.
Q8: Which of the following correctly describes a key structural difference between DNA and RNA molecules?
A. DNA contains uracil; RNA contains thymine
, B. DNA is single-stranded; RNA is double-stranded
C. DNA contains deoxyribose sugar and thymine; RNA contains ribose sugar and uracil [CORRECT]
D. DNA has peptide bonds; RNA has glycosidic bonds
Correct Answer: C
Rationale: DNA contains the five-carbon sugar deoxyribose (lacking a hydroxyl group at the 2-prime carbon) and the nitrogenous base
thymine, while RNA contains ribose (with a hydroxyl group at the 2-prime carbon) and the base uracil instead of thymine. DNA is typically
double-stranded while RNA is typically single-stranded, but the sugar and base differences are the fundamental biochemical distinctions.
Neither molecule contains peptide bonds; both contain glycosidic bonds between their sugar and base components.
Q9: A protein is composed of a specific sequence of amino acids linked together. What type of chemical bond forms
between adjacent amino acids in a growing polypeptide chain?
A. Glycosidic bond
B. Ester bond
C. Peptide bond [CORRECT]
D. Hydrogen bond
Correct Answer: C
Rationale: A peptide bond is a covalent bond formed between the carboxyl group (-COOH) of one amino acid and the amino group (-NH2)
of another amino acid through a condensation reaction, releasing a molecule of water. This bond is the fundamental linkage in all proteins
and polypeptides. Glycosidic bonds link monosaccharides. Ester bonds link fatty acids to glycerol. Hydrogen bonds contribute to protein
secondary structure but do not link amino acids in the primary sequence.
Q10: Glucose and fructose both have the chemical formula C6H12O6 but differ in their structural arrangement. What is the
term for molecules that share the same molecular formula but have different structural formulas?
A. Isomers [CORRECT]
B. Polymers
C. Monomers
D. Isotopes
Correct Answer: A
Rationale: Isomers are molecules that share the same molecular formula (same number and type of atoms) but have different structural
arrangements, resulting in different chemical properties. Glucose and fructose are classic examples of structural isomers: both are hexoses
(C6H12O6) but glucose is an aldose (aldehyde group) while fructose is a ketose (ketone group). Polymers are large molecules made of
repeating monomer subunits. Monomers are the individual building blocks. Isotopes are atoms of the same element with different numbers of
neutrons.
Q11: Which of the following correctly lists the four main categories of organic molecules essential for life
(macromolecules)?
A. Carbohydrates, lipids, proteins, and nucleic acids [CORRECT]
B. Carbohydrates, minerals, proteins, and vitamins
C. Lipids, water, nucleic acids, and amino acids
D. Proteins, carbohydrates, electrolytes, and hormones
Correct Answer: A
Rationale: The four main categories of biological macromolecules (organic molecules essential for life) are carbohydrates (sugars, starches,
cellulose), lipids (fats, phospholipids, steroids), proteins (enzymes, structural molecules, antibodies), and nucleic acids (DNA, RNA). These
four categories are universally recognized in biochemistry and cell biology. Minerals, vitamins, electrolytes, and hormones are important
biomolecules but are not classified among the four primary macromolecular categories.
Q12: A lipid molecule is described as having little to no affinity for water, being mostly hydrophobic, and being soluble in
organic solvents such as ethanol but insoluble in water. Which category of biomolecule does this description best
Semmelweis University Medicine Biology Entrance Examination 2026/2027
Questions and Answers - Verified by Expert
Semmelweis University Faculty of Medicine | 100 Questions | Aligned with Official Admission Requirements
Section 1: Biochemistry and Molecules of Life
Questions 1-15
Q1: A biology student is analyzing two monosaccharide molecules that have been joined together. The reaction consumed
one water molecule during the formation of the bond. What type of chemical reaction occurred, and what type of bond was
formed between the two monosaccharides?
A. Hydrolysis reaction forming a peptide bond
B. Condensation reaction forming a glycosidic bond [CORRECT]
C. Oxidation reaction forming an ester bond
D. Reduction reaction forming a hydrogen bond
Correct Answer: B
Rationale: When two monosaccharides join, a condensation (dehydration synthesis) reaction occurs in which one molecule of water is
removed. The bond formed between the two sugar molecules is called a glycosidic bond. Hydrolysis is the reverse process that breaks
glycosidic bonds. Peptide bonds form between amino acids, not monosaccharides. Ester bonds form between fatty acids and glycerol in
triglyceride synthesis.
Q2: Which of the following polysaccharides functions as a structural component in plant cell walls rather than as an energy
storage molecule?
A. Glycogen
B. Starch
C. Cellulose [CORRECT]
D. Sucrose
Correct Answer: C
Rationale: Cellulose is a structural polysaccharide composed of beta-glucose monomers linked by beta-1,4-glycosidic bonds, making it
insoluble in water and ideal for forming rigid plant cell walls. Glycogen and starch are energy storage polysaccharides in animals and plants
respectively, composed of alpha-glucose. Sucrose is a disaccharide, not a polysaccharide, and serves as a transport sugar in plants.
Q3: A researcher is comparing saturated and unsaturated fatty acids. She observes that one fatty acid has no double bonds in
its hydrocarbon chain while another has two double bonds with hydrogen atoms on the same side. Which statement correctly
describes these two fatty acids?
A. The first is cis-unsaturated; the second is trans-saturated
B. The first is saturated; the second is cis-unsaturated [CORRECT]
C. Both are unsaturated but differ only in chain length
D. The first is trans-unsaturated; the second is saturated
Correct Answer: B
Rationale: Saturated fatty acids contain no carbon-carbon double bonds in their hydrocarbon chains, with each carbon fully bonded to
hydrogen atoms. Unsaturated fatty acids have one or more double bonds; when the hydrogen atoms attached to the double-bonded carbons
are on the same side, the isomer is designated as cis. Trans isomers have hydrogen atoms on opposite sides of the double bond. The
description clearly distinguishes a saturated fatty acid from a cis-unsaturated one.
Q4: Triglycerides are formed through the condensation of one glycerol molecule and three fatty acid molecules. What type
of chemical bond is formed between the glycerol and each fatty acid during this process?
Page 1
, A. Glycosidic bond
B. Peptide bond
C. Ester bond [CORRECT]
D. Phosphodiester bond
Correct Answer: C
Rationale: In triglyceride formation, each fatty acid undergoes a condensation reaction with the hydroxyl groups of glycerol, forming three
ester bonds (also called ester linkages) and releasing three water molecules. Glycosidic bonds form between monosaccharides. Peptide bonds
form between amino acids in protein synthesis. Phosphodiester bonds connect nucleotides in DNA and RNA strands.
Q5: A student is studying the properties of water that make it essential for biological systems. Which property of water is
most directly responsible for its ability to act as a solvent for many ionic and polar substances?
A. High specific heat capacity
B. Cohesion and adhesion
C. Polarity and hydrogen bonding [CORRECT]
D. High heat of vaporization
Correct Answer: C
Rationale: Water is a polar molecule with a partial negative charge near the oxygen atom and partial positive charges near the hydrogen
atoms. This polarity, combined with the ability to form hydrogen bonds, allows water to dissolve ionic and polar substances effectively. While
water high specific heat capacity, cohesion, and heat of vaporization are all biologically important properties, solvent capability is most
directly attributable to its molecular polarity and hydrogen bonding capacity.
Q6: A hydrogen bond can form between a hydrogen atom covalently bonded to which of the following elements and
another electronegative atom?
A. Carbon (C)
B. Nitrogen (N), Oxygen (O), or Fluorine (F) [CORRECT]
C. Sulfur (S)
D. Phosphorus (P)
Correct Answer: B
Rationale: Hydrogen bonds are a specific type of intermolecular attractive force that occurs when a hydrogen atom is covalently bonded to a
highly electronegative atom (nitrogen, oxygen, or fluorine) and is attracted to another electronegative atom nearby. The large
electronegativity difference creates a strong dipole, allowing the partially positive hydrogen to interact with lone pairs on adjacent
electronegative atoms. Carbon, sulfur, and phosphorus are not sufficiently electronegative to participate in hydrogen bonding.
Q7: In a laboratory experiment, a polysaccharide is treated with an enzyme that breaks the glycosidic bonds between
glucose monomers. This reaction consumes water molecules to break each bond. What is the correct term for this type of
reaction?
A. Condensation
B. Hydrolysis [CORRECT]
C. Dehydration synthesis
D. Oxidation
Correct Answer: B
Rationale: Hydrolysis is the chemical reaction that breaks bonds by the addition of a water molecule, essentially the reverse of condensation
(dehydration synthesis). In this case, water is consumed to cleave the glycosidic bonds holding the glucose monomers together in the
polysaccharide. Condensation removes water to form bonds. Dehydration synthesis is another name for condensation. Oxidation involves
electron transfer, not water-mediated bond cleavage.
Q8: Which of the following correctly describes a key structural difference between DNA and RNA molecules?
A. DNA contains uracil; RNA contains thymine
, B. DNA is single-stranded; RNA is double-stranded
C. DNA contains deoxyribose sugar and thymine; RNA contains ribose sugar and uracil [CORRECT]
D. DNA has peptide bonds; RNA has glycosidic bonds
Correct Answer: C
Rationale: DNA contains the five-carbon sugar deoxyribose (lacking a hydroxyl group at the 2-prime carbon) and the nitrogenous base
thymine, while RNA contains ribose (with a hydroxyl group at the 2-prime carbon) and the base uracil instead of thymine. DNA is typically
double-stranded while RNA is typically single-stranded, but the sugar and base differences are the fundamental biochemical distinctions.
Neither molecule contains peptide bonds; both contain glycosidic bonds between their sugar and base components.
Q9: A protein is composed of a specific sequence of amino acids linked together. What type of chemical bond forms
between adjacent amino acids in a growing polypeptide chain?
A. Glycosidic bond
B. Ester bond
C. Peptide bond [CORRECT]
D. Hydrogen bond
Correct Answer: C
Rationale: A peptide bond is a covalent bond formed between the carboxyl group (-COOH) of one amino acid and the amino group (-NH2)
of another amino acid through a condensation reaction, releasing a molecule of water. This bond is the fundamental linkage in all proteins
and polypeptides. Glycosidic bonds link monosaccharides. Ester bonds link fatty acids to glycerol. Hydrogen bonds contribute to protein
secondary structure but do not link amino acids in the primary sequence.
Q10: Glucose and fructose both have the chemical formula C6H12O6 but differ in their structural arrangement. What is the
term for molecules that share the same molecular formula but have different structural formulas?
A. Isomers [CORRECT]
B. Polymers
C. Monomers
D. Isotopes
Correct Answer: A
Rationale: Isomers are molecules that share the same molecular formula (same number and type of atoms) but have different structural
arrangements, resulting in different chemical properties. Glucose and fructose are classic examples of structural isomers: both are hexoses
(C6H12O6) but glucose is an aldose (aldehyde group) while fructose is a ketose (ketone group). Polymers are large molecules made of
repeating monomer subunits. Monomers are the individual building blocks. Isotopes are atoms of the same element with different numbers of
neutrons.
Q11: Which of the following correctly lists the four main categories of organic molecules essential for life
(macromolecules)?
A. Carbohydrates, lipids, proteins, and nucleic acids [CORRECT]
B. Carbohydrates, minerals, proteins, and vitamins
C. Lipids, water, nucleic acids, and amino acids
D. Proteins, carbohydrates, electrolytes, and hormones
Correct Answer: A
Rationale: The four main categories of biological macromolecules (organic molecules essential for life) are carbohydrates (sugars, starches,
cellulose), lipids (fats, phospholipids, steroids), proteins (enzymes, structural molecules, antibodies), and nucleic acids (DNA, RNA). These
four categories are universally recognized in biochemistry and cell biology. Minerals, vitamins, electrolytes, and hormones are important
biomolecules but are not classified among the four primary macromolecular categories.
Q12: A lipid molecule is described as having little to no affinity for water, being mostly hydrophobic, and being soluble in
organic solvents such as ethanol but insoluble in water. Which category of biomolecule does this description best
