Chemical Reactions
(Energy)
I. Energy – Stored in Chemical ______,
especially (__-__) bonds.
I. Energy – Stored in Chemical Bonds,
especially (C-H) bonds.
• Different forms of energy:
A. ________ energy (sunlight)
B. ________ energy (chemical bonds)
C. ________ energy (movement)
I. Energy – Stored in Chemical Bonds,
especially (C-H) bonds.
• Different forms of energy:
A. Radiant/Solar energy (sunlight)
B. Chemical energy (chemical bonds)
C. Kinetic/thermal energy (movement &
heat)
II. Two Laws of Thermodynamics
• 1st Law: Energy cannot be _________ or
__________. It is simply ________________.
II. Two Laws of Thermodynamics
• 1st Law: Energy cannot be created or
destroyed. It is simply transferred.
Example: Lawnmower
gasoline = _______ E
bonds break, ________ released
Pressure increases, pistons _______
II. Two Laws of Thermodynamics
• 1st Law: Energy cannot be created or destroyed.
It is simply transferred.
Example: Lawnmower
gasoline = _bond E
bonds break, heat released
Pressure increases, pistons move
**Overall Energy transfer:
______E to ______E
**Respiration!! (Consume ______→_____)
II. Two Laws of Thermodynamics
• 1st Law: Energy cannot be created or destroyed.
It is simply transferred.
Example: Lawnmower
gasoline = bond E
bonds break, heat released
Pressure increases, pistons move
**Overall Energy transfer:
bond E to kinetic E
**Respiration!! (Consume ______→_____)
II. Two Laws of Thermodynamics
• 1st Law: Energy cannot be created or destroyed.
It is simply transferred.
Example: Lawnmower
gasoline = bond E
bonds break, heat released
Pressure increases, pistons move
**Overall Energy transfer:
bond E to kinetic E
**Respiration!! (Consume food → ATP)
II. Two Laws of Thermodynamics
• 2nd Law: Entropy (disorganization) tends to
___________ as energy is transferred (over time).
• Ex) Chemical digestion
_______________
_________ ________
II. Two Laws of Thermodynamics
• 2nd Law: Entropy (disorganization) tends to
_increase_ as energy is transferred.
• Ex) Chemical digestion
_______________
_________ ________
II. Two Laws of Thermodynamics
• 2nd Law: Entropy (disorganization) tends to
_increase_ as energy is transferred.
• Ex) Chemical digestion
1 polypeptide
_________ ________
II. Two Laws of Thermodynamics
• 2nd Law: Entropy (disorganization) tends to
_increase_ as energy is transferred.
• Ex) Chemical digestion
1 polypeptide
150 Amino Acids
II. Two Laws of Thermodynamics
• Increased disorder (entropy) is offset by
biological processes that maintain order.
II. Two Laws of Thermodynamics
• Increased disorder (entropy) is offset by
biological processes that maintain order.
• Living systems do not violate the _______Law
(States that entropy increases with time)
II. Two Laws of Thermodynamics
• Increased disorder (entropy) is offset by
biological processes that maintain order.
• Living systems do not violate the _2nd Law
(States that entropy increases with time)
• How is order maintained?
• By coupling processes that ________entropy
with those that __________order.
II. Two Laws of Thermodynamics
• Increased disorder (entropy) is offset by
biological processes that maintain order.
• Living systems do not violate the _2nd Law
(States that entropy increases with time)
• How is order maintained?
• By coupling (stacking) processes that increase
entropy with those that maintain order.
II. Two Laws of Thermodynamics
• Example: The making of a protein inside a cell:
________ ________ → _______________
II. Two Laws of Thermodynamics
• Example: The making of a protein inside a cell:
Amino Acids → Polypeptide_
II. Two Laws of Thermodynamics
• Example: The making of a protein inside a cell:
Use of ATP (1st reaction)
Amino Acids → Polypeptide_ (2nd reaction)
**Not a spontaneous reaction – ATP helps
in maintaining order.
III. Endergonic Reactions
• Chemical reactions require “start-up” energy
known as __________energy.
III. Endergonic Reactions
• Chemical reactions require “start-up” energy
known as activation energy.
• Endergonic (Energy “___”) - Products have
_________ free energy (positive ∆G) than
reactants.
III. Endergonic Reactions
• Chemical reactions require “start-up” energy
known as activation energy.
• Endergonic (Energy “in”) - Products have more
free energy (positive ∆G) than reactants.
Example: Photosynthesis
______ + ______ → ______ + _______
III. Endergonic Reactions
• Chemical reactions require “start-up” energy
known as activation energy.
• Endergonic (Energy “in”): Products have more
free energy (positive ∆G) than reactants.
Example: Photosynthesis
carbon dioxide + water → oxygen + glucose
Energy Source???
minimum amount of
. Activation energy- __________
energy required to get a chemical reaction
started.
IV. Exergonic Reactions
• Exergonic = Energy “____”- Products have
______ free energy (________ ∆G) than
reactants.
IV. Exergonic Reactions
• Exergonic = Energy “out” - Products have less
free energy (_________∆G) than reactants.
IV. Exergonic Reactions
• Exergonic = Energy “out” - Products have less
free energy (_negative ∆G) than reactants.
IV. Exergonic Reactions
• Exergonic = Energy “out” - Products have less
free energy (_negative ∆G) than reactants.
• Tend to be _________ spontaneous than
endergonic reactions!
IV. Exergonic Reactions
• Exergonic = Energy “out” - Products have less
free energy (_negative ∆G) than reactants.
• Tend to be more spontaneous than
endergonic reactions! Require less Activation E!
Example: Respiration
_____ + _____ → ______ + _____+ _______
IV. Exergonic Reactions
• Exergonic = Energy “out” - Products have less
free energy (_negative ∆G) than reactants.
• Tend to be more spontaneous than
endergonic reactions! Require less Activation E!
Example: Respiration
oxygen + glucose → carbon dioxide + water +
36 ATPs
4. Endergonic reactions= reactants have less
energy than products (energy must go into
reaction).
5. Exergonic reactions= reactants have more
energy than products (energy leaves reaction).
V. Free Energy Changes in a
Reaction Lead to Changes in
Entropy, Stability, and
Capacity to do Work
• More Free Energy at end of process
(____________ reaction) means that Entropy
is _____________
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
_____________
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• Products are ___________ Stable.
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• Products are _less_ Stable.
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• Products are _less_ Stable. (Products have
more bond E therefore, more likely to react)
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• Products are _less_ Stable. (Products have
more bond E therefore, more likely to react)
• Work Capacity (energy available to the cell)
______________.
• More Free Energy at end of process
(Endergonic reaction) means that Entropy is
Decreased. (Example: Photosynthesis
CO2
C6H12O6)
• Products are _less_ Stable. (Products have
more bond E therefore, more likely to react)
• Work Capacity (energy available to the cell)
Increases. (Greater Work Capacity)
• Less Free Energy at end of reaction =
___________ reaction (i.e. glucose → CO2 in
Respiration) means that:
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is ____________.
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is Increased.
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is Increased.
• ________ _Stable_
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration)
• Entropy is Increased.
• More _Stable_
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is Increased.
• More _Stable_ (Products have less bond E,
therefore, are less likely to react)
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is Increased.
• More _Stable_(Products have less bond E,
therefore, are less likely to react)
• ___________ Work Capacity
• Less Free Energy at end of reaction =
Exergonic reaction (i.e. glucose → CO2 in
Respiration) means that:
• Entropy is Increased.
• More _Stable_(Products have less bond E,
therefore, are less likely to react)
• Decreased Work Capacity
Free Energy Changes Leads to Changes in
Entropy, Stability, and Capacity to do Work