IB 150 Unit 1 Learning Goals Questions With Complete
Solutions
Be able to identify the most common sources of chemical
potential energy. Correct Answers Glucose (in the C-H bonds)
ATP (in the O-P bonds)
Be able to use these terms in context: catalyst, enzyme, active
site Correct Answers Catalyst: Increases the rate of a reaction
without any permanent chemical change.
Enzyme: a protein catalyst to speed up and control reactions
Active Site: The location in an enzyme molecule where reactant
molecules bind and react.
Define diffusion versus osmosis. Correct Answers Diffusion: is
a spontaneous movement of particles from an area of high
concentration to an area of low concentration
Osmosis: is the spontaneous net movement of water across a
semipermeable membrane from a region of low solute
concentration to a more concentrated solution, up a
concentration gradient.
Define exergonic and endergonic chemical reactions. Correct
Answers Exergonic Reactions
-Release energy (can be used to do work)
-Tend to be spontaneous
-Reactants have a higher Gibbs Free Energy than the products
-ΔH (Enthalpy) is negative (heat given off)
, -ΔS (Entropy) is positive
Endergonic Reactions
-Requires energy to be done on the system for the reaction to
proceed
-ΔH (Enthalpy) is positive (heat absorbed)
Define the First and Second Law of Thermodynamics Correct
Answers -First Law of Thermodynamics - Energy is conserved,
it cannot be created or destroyed, but only transferred and
transformed
-Second Law of Thermodynamics - entropy always increases in
an isolated system (delta G of the universe wants to go to
disorder).
Describe the role of cellular respiration in the transfer of energy
from glucose to work done in the cell Correct Answers The
reaction steps in Cellular Respiration break apart the bonds in
Glucose to create ATP which fuels all of the body processes,
and allows the cells to do work.
Determine whether a change of a system increases or decreases
in enthalpy (ΔH) and entropy (ΔS) over the course of the
reaction. Correct Answers -Spontaneous Reaction - products
have lower potential energy than the reactants (electrons in
products are held more tightly than those in the reactants)
-A reaction is favorable if entropy increases. (ΔS) dispersal of
energy and matter (disorder)
Solutions
Be able to identify the most common sources of chemical
potential energy. Correct Answers Glucose (in the C-H bonds)
ATP (in the O-P bonds)
Be able to use these terms in context: catalyst, enzyme, active
site Correct Answers Catalyst: Increases the rate of a reaction
without any permanent chemical change.
Enzyme: a protein catalyst to speed up and control reactions
Active Site: The location in an enzyme molecule where reactant
molecules bind and react.
Define diffusion versus osmosis. Correct Answers Diffusion: is
a spontaneous movement of particles from an area of high
concentration to an area of low concentration
Osmosis: is the spontaneous net movement of water across a
semipermeable membrane from a region of low solute
concentration to a more concentrated solution, up a
concentration gradient.
Define exergonic and endergonic chemical reactions. Correct
Answers Exergonic Reactions
-Release energy (can be used to do work)
-Tend to be spontaneous
-Reactants have a higher Gibbs Free Energy than the products
-ΔH (Enthalpy) is negative (heat given off)
, -ΔS (Entropy) is positive
Endergonic Reactions
-Requires energy to be done on the system for the reaction to
proceed
-ΔH (Enthalpy) is positive (heat absorbed)
Define the First and Second Law of Thermodynamics Correct
Answers -First Law of Thermodynamics - Energy is conserved,
it cannot be created or destroyed, but only transferred and
transformed
-Second Law of Thermodynamics - entropy always increases in
an isolated system (delta G of the universe wants to go to
disorder).
Describe the role of cellular respiration in the transfer of energy
from glucose to work done in the cell Correct Answers The
reaction steps in Cellular Respiration break apart the bonds in
Glucose to create ATP which fuels all of the body processes,
and allows the cells to do work.
Determine whether a change of a system increases or decreases
in enthalpy (ΔH) and entropy (ΔS) over the course of the
reaction. Correct Answers -Spontaneous Reaction - products
have lower potential energy than the reactants (electrons in
products are held more tightly than those in the reactants)
-A reaction is favorable if entropy increases. (ΔS) dispersal of
energy and matter (disorder)
