BIOC 3021 EXAM 1 QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
What are the bonding characteristics of carbon? - Answers Carbon has 4 outer shell electrons, can
form 4 bonds, and can create single, double, or triple bonds.
What is the significance of carbon's ability to form complex 3D structures? - Answers Carbon's ability
to form complex 3D structures allows for the formation of diverse biomolecules.
How do carbon-carbon single bonds affect molecular shape? - Answers Carbon-carbon single bonds
can rotate, altering the 3-dimensional shape of the molecule.
What is reduction in terms of electron transfer? - Answers Reduction is the gain of electrons.
What is oxidation in terms of electron transfer? - Answers Oxidation is the loss of electrons.
What are oxidation-reduction reactions? - Answers Reactions where an atom is oxidized when it loses
a share in electrons and reduced when it gains a share.
How is the oxidation number of a monatomic ion determined? - Answers It is equal to its charge.
What happens to the oxidation state of carbon when it bonds with hydrogen? - Answers Every bond
between carbon and hydrogen decreases the oxidation state by 1.
What happens to the oxidation state of carbon when it bonds with more electronegative elements? -
Answers Every bond between carbon and a more electronegative element increases the oxidation
state by 1.
What is the oxidation state of carbon in methane (CH4)? - Answers The oxidation state of carbon in
methane is -4.
What is the general formula for saturated hydrocarbons (alkanes)? - Answers C(n)H(2n+2)
What is the general formula for unsaturated hydrocarbons (alkenes)? - Answers C(n)H(2n)
What makes alcohols polar? - Answers Alcohols are polar due to the O-H bond.
Why are carbon chains considered hydrophobic? - Answers Carbon chains are non-polar and water
insoluble.
What is the importance of functional groups in organic chemistry? - Answers Functional groups
determine the chemical properties and reactivity of organic compounds.
What is the oxidation state of carbon in ethane (C2H6)? - Answers The oxidation state of carbon in
ethane is -3.
How does the oxidation state of carbon change in propane (C3H8)? - Answers The middle carbon in
propane has an oxidation state of -2.
What is the role of redox reactions in metabolism? - Answers Redox reactions are the main way cells
capture energy from food.
How do carbon atoms in fatty acids and carbohydrates change during catabolism? - Answers They are
oxidized to CO2, releasing energy.
What is the general formula for aldehydes? - Answers RCHO, where the carbonyl group is at the end
of the carbon chain.
What is the general formula for ketones? - Answers RCOR', where the carbonyl group is in the interior
of the carbon chain.
What are the three main components of an amino acid? - Answers An amino group, a carboxylic acid
group, and a side chain (R).
How are carbons labeled in amino acid backbones? - Answers Starting from the functional groups,
they are labeled C-alpha, C-beta, C-gamma, C-delta, C-epsilon, etc.
What are isomers? - Answers Different forms of a compound that have the same atoms but differ in
structure or arrangement.
What are stereoisomers? - Answers Isomers that have the same molecular formula and connectivity
but differ in the spatial arrangement of atoms.
What is the biological significance of stereoisomers? - Answers Different stereoisomers can have
different biological effects; for example, one isomer of thalidomide is a sedative while another causes
birth defects.
What is the Bronsted acid/base theory? - Answers It defines acids as proton donors and bases as
proton acceptors.
What happens to strong acids in water? - Answers They dissociate completely, e.g., HCl dissociates
into H+ and Cl-.
How do weak acids behave in water? - Answers They only partially dissociate, e.g., acetic acid
(CH3COOH) partially dissociates into CH3COO- and H3O+.
, What is the Henderson-Hasselbalch equation? - Answers pH = pKa + log [A-]/[HA], used to calculate
the pH of buffer solutions.
What is the significance of the pH scale? - Answers It measures the acidity or basicity of a solution,
which is determined by the concentration of H+ ions.
What is a tri-protic acid? - Answers An acid that can donate three protons, such as phosphoric acid
(H3PO4).
What is the primary source of metabolic acid in the body? - Answers Carbon dioxide (CO2), which is in
rapid equilibrium with carbonic acid and bicarbonate ion.
What is the dissociation of water? - Answers Water dissociates into H+ and OH- ions, establishing the
pH scale.
What is the role of buffers in biological systems? - Answers Buffers resist changes in pH by
maintaining equilibrium between weak acids and their conjugate bases.
What are the pKa values of carbonic acid? - Answers The pKa values are 6.3 and 10.3, indicating its
role as a buffer in the body.
What is the impact of different isomers on smell? - Answers Different isomers can produce different
odors due to variations in molecular structure.
How does a bond between carbon and hydrogen affect the oxidation state? - Answers It decreases
the oxidation state by 1.
What effect does a bond between carbon and a more electronegative element have on the oxidation
state? - Answers It increases the oxidation state by 1.
What is the highest oxidation state of carbon, and in which compound does it occur? - Answers +4 in
carbon dioxide (CO₂).
What is the oxidation state of carbon in carbon monoxide (CO)? - Answers +2
What is the oxidation state of carbon in formaldehyde (CH₂O)? - Answers 0
What is the Henderson-Hasselbalch equation used for? - Answers It is used to calculate the pH of a
buffer solution.
What does the term 'tri-protic acid' refer to in relation to phosphoric acid? - Answers It means
phosphoric acid can donate three protons, having three pKa values.
What does the First Law of Thermodynamics state? - Answers Energy cannot be created or destroyed;
it can only be converted from one form to another.
What does the Second Law of Thermodynamics describe? - Answers It states that systems tend to
change from low entropy (ordered) to high entropy (disordered).
What is bond dissociation energy? - Answers The amount of energy required to break a bond and
separate the atoms in an isolated gaseous molecule.
What does ΔH represent in a chemical reaction? - Answers The change in heat content or enthalpy
during a reaction.
What is Gibbs Free Energy (G) used to predict? - Answers It predicts whether a reaction is
spontaneous or not.
What does it mean if ΔG < 0? - Answers The reaction occurs spontaneously (exergonic).
What does it mean if ΔG > 0? - Answers The reaction requires energy to occur (endergonic).
What is an endothermic reaction? - Answers A reaction that absorbs heat and has a positive ΔH.
What is an exothermic reaction? - Answers A reaction that releases heat and has a negative ΔH.
What does the heat of reaction (ΔH) represent? - Answers The difference between the energy
absorbed in breaking bonds and that released in forming bonds.
What is the relationship between bond strength and energy release in exothermic reactions? -
Answers Energy is released when the total strength of the bonds formed in products is greater than
that of bonds broken in reactants.
What is the enthalpy change (ΔH) for glucose oxidation? - Answers ΔH = -285 kcal/mol
What type of reaction is glucose synthesis? - Answers An endothermic reaction
What does a negative ΔG indicate about a reaction? - Answers The reaction is spontaneous.
What is activation energy (Ea)? - Answers The minimum energy required for a reaction to occur.
What does the equilibrium constant (Keq) represent? - Answers The ratio of concentrations of
products to reactants at equilibrium.
What happens when Keq > 1.0? - Answers Products predominately exist at equilibrium.
What is the relationship between ΔG and Keq at equilibrium? - Answers ΔG = 0 and ΔG° = -RT ln(Keq)
What is the standard state free energy change (ΔG°)? - Answers The free energy change under
standard conditions of pressure and temperature.
What are the bonding characteristics of carbon? - Answers Carbon has 4 outer shell electrons, can
form 4 bonds, and can create single, double, or triple bonds.
What is the significance of carbon's ability to form complex 3D structures? - Answers Carbon's ability
to form complex 3D structures allows for the formation of diverse biomolecules.
How do carbon-carbon single bonds affect molecular shape? - Answers Carbon-carbon single bonds
can rotate, altering the 3-dimensional shape of the molecule.
What is reduction in terms of electron transfer? - Answers Reduction is the gain of electrons.
What is oxidation in terms of electron transfer? - Answers Oxidation is the loss of electrons.
What are oxidation-reduction reactions? - Answers Reactions where an atom is oxidized when it loses
a share in electrons and reduced when it gains a share.
How is the oxidation number of a monatomic ion determined? - Answers It is equal to its charge.
What happens to the oxidation state of carbon when it bonds with hydrogen? - Answers Every bond
between carbon and hydrogen decreases the oxidation state by 1.
What happens to the oxidation state of carbon when it bonds with more electronegative elements? -
Answers Every bond between carbon and a more electronegative element increases the oxidation
state by 1.
What is the oxidation state of carbon in methane (CH4)? - Answers The oxidation state of carbon in
methane is -4.
What is the general formula for saturated hydrocarbons (alkanes)? - Answers C(n)H(2n+2)
What is the general formula for unsaturated hydrocarbons (alkenes)? - Answers C(n)H(2n)
What makes alcohols polar? - Answers Alcohols are polar due to the O-H bond.
Why are carbon chains considered hydrophobic? - Answers Carbon chains are non-polar and water
insoluble.
What is the importance of functional groups in organic chemistry? - Answers Functional groups
determine the chemical properties and reactivity of organic compounds.
What is the oxidation state of carbon in ethane (C2H6)? - Answers The oxidation state of carbon in
ethane is -3.
How does the oxidation state of carbon change in propane (C3H8)? - Answers The middle carbon in
propane has an oxidation state of -2.
What is the role of redox reactions in metabolism? - Answers Redox reactions are the main way cells
capture energy from food.
How do carbon atoms in fatty acids and carbohydrates change during catabolism? - Answers They are
oxidized to CO2, releasing energy.
What is the general formula for aldehydes? - Answers RCHO, where the carbonyl group is at the end
of the carbon chain.
What is the general formula for ketones? - Answers RCOR', where the carbonyl group is in the interior
of the carbon chain.
What are the three main components of an amino acid? - Answers An amino group, a carboxylic acid
group, and a side chain (R).
How are carbons labeled in amino acid backbones? - Answers Starting from the functional groups,
they are labeled C-alpha, C-beta, C-gamma, C-delta, C-epsilon, etc.
What are isomers? - Answers Different forms of a compound that have the same atoms but differ in
structure or arrangement.
What are stereoisomers? - Answers Isomers that have the same molecular formula and connectivity
but differ in the spatial arrangement of atoms.
What is the biological significance of stereoisomers? - Answers Different stereoisomers can have
different biological effects; for example, one isomer of thalidomide is a sedative while another causes
birth defects.
What is the Bronsted acid/base theory? - Answers It defines acids as proton donors and bases as
proton acceptors.
What happens to strong acids in water? - Answers They dissociate completely, e.g., HCl dissociates
into H+ and Cl-.
How do weak acids behave in water? - Answers They only partially dissociate, e.g., acetic acid
(CH3COOH) partially dissociates into CH3COO- and H3O+.
, What is the Henderson-Hasselbalch equation? - Answers pH = pKa + log [A-]/[HA], used to calculate
the pH of buffer solutions.
What is the significance of the pH scale? - Answers It measures the acidity or basicity of a solution,
which is determined by the concentration of H+ ions.
What is a tri-protic acid? - Answers An acid that can donate three protons, such as phosphoric acid
(H3PO4).
What is the primary source of metabolic acid in the body? - Answers Carbon dioxide (CO2), which is in
rapid equilibrium with carbonic acid and bicarbonate ion.
What is the dissociation of water? - Answers Water dissociates into H+ and OH- ions, establishing the
pH scale.
What is the role of buffers in biological systems? - Answers Buffers resist changes in pH by
maintaining equilibrium between weak acids and their conjugate bases.
What are the pKa values of carbonic acid? - Answers The pKa values are 6.3 and 10.3, indicating its
role as a buffer in the body.
What is the impact of different isomers on smell? - Answers Different isomers can produce different
odors due to variations in molecular structure.
How does a bond between carbon and hydrogen affect the oxidation state? - Answers It decreases
the oxidation state by 1.
What effect does a bond between carbon and a more electronegative element have on the oxidation
state? - Answers It increases the oxidation state by 1.
What is the highest oxidation state of carbon, and in which compound does it occur? - Answers +4 in
carbon dioxide (CO₂).
What is the oxidation state of carbon in carbon monoxide (CO)? - Answers +2
What is the oxidation state of carbon in formaldehyde (CH₂O)? - Answers 0
What is the Henderson-Hasselbalch equation used for? - Answers It is used to calculate the pH of a
buffer solution.
What does the term 'tri-protic acid' refer to in relation to phosphoric acid? - Answers It means
phosphoric acid can donate three protons, having three pKa values.
What does the First Law of Thermodynamics state? - Answers Energy cannot be created or destroyed;
it can only be converted from one form to another.
What does the Second Law of Thermodynamics describe? - Answers It states that systems tend to
change from low entropy (ordered) to high entropy (disordered).
What is bond dissociation energy? - Answers The amount of energy required to break a bond and
separate the atoms in an isolated gaseous molecule.
What does ΔH represent in a chemical reaction? - Answers The change in heat content or enthalpy
during a reaction.
What is Gibbs Free Energy (G) used to predict? - Answers It predicts whether a reaction is
spontaneous or not.
What does it mean if ΔG < 0? - Answers The reaction occurs spontaneously (exergonic).
What does it mean if ΔG > 0? - Answers The reaction requires energy to occur (endergonic).
What is an endothermic reaction? - Answers A reaction that absorbs heat and has a positive ΔH.
What is an exothermic reaction? - Answers A reaction that releases heat and has a negative ΔH.
What does the heat of reaction (ΔH) represent? - Answers The difference between the energy
absorbed in breaking bonds and that released in forming bonds.
What is the relationship between bond strength and energy release in exothermic reactions? -
Answers Energy is released when the total strength of the bonds formed in products is greater than
that of bonds broken in reactants.
What is the enthalpy change (ΔH) for glucose oxidation? - Answers ΔH = -285 kcal/mol
What type of reaction is glucose synthesis? - Answers An endothermic reaction
What does a negative ΔG indicate about a reaction? - Answers The reaction is spontaneous.
What is activation energy (Ea)? - Answers The minimum energy required for a reaction to occur.
What does the equilibrium constant (Keq) represent? - Answers The ratio of concentrations of
products to reactants at equilibrium.
What happens when Keq > 1.0? - Answers Products predominately exist at equilibrium.
What is the relationship between ΔG and Keq at equilibrium? - Answers ΔG = 0 and ΔG° = -RT ln(Keq)
What is the standard state free energy change (ΔG°)? - Answers The free energy change under
standard conditions of pressure and temperature.
