1. LEQ: What is the role of ATP in cellular activities?
Cellular Energy
Pages 72 to 75

2. Energy What is energy? What is Kinetic energy?
The capacity to do work
What is Kinetic energy?
Energy of motion
Heat (thermal energy) is kinetic energy given off due the the movement of molecules
What is Potential energy?
Stored energy that an object possess as a result of its location or structure
Chemical energy is potential energy available for release in a chemical reaction

3. Climbing up converts the kinetic
energy of muscle movement
to potential energy.
A diver has less potential
energy in the water
than on the platform.
Diving converts
potential energy to
kinetic energy.
A diver has more potential
energy on the platform
than in the water.

4. Thermodynamics What is thermodynamics?
The study of energy transformation
Organisms are open systems
In an open system, energy and matter can be transferred between the system and its environment

5. The First Law of Thermodynamics
According to the first law of thermodynamics, the energy of the universe is constant:
– Energy can be transferred and transformed, but it cannot be created or destroyed
The first law is also called the principle of conservation of energy

6. The Second Law of Thermodynamics
During every energy transfer or transformation, some energy is unusable, and is often lost as heat
According to the second law of thermodynamics:
– Every energy transfer or transformation increases the entropy (disorder) of the universe

7. (a) First law of thermodynamics (b) Second law of thermodynamics Heat
Chemical
energy
Heat
CO2
H2O +

8. Biological Order and Disorder
Living things are ordered, decreasing entropy - this requires an input of energy, increasing entropy….
Building macromolecules (dehydration synthesis) decreases entropy by organizing atoms into molecules, molecules into cells, etc…
In order to build / maintain organization requires an input of energy which increases entropy

10. Chemical Reactions Endergonic Reactions “Energy In”
Require a net input of energy
Rich in potential energy
Photosynthesis – takes in energy to produce sugar; energy stored in bonds

11. Progress of the reaction
Fig. 8-6b
Products
Amount of
energy
required
(∆G > 0)
Energy
Free energy
Reactants
Figure 8.6b Free energy changes (ΔG) in exergonic and endergonic reactions
Progress of the reaction
(b) Endergonic reaction: energy required

12. Chemical Reactions Exergonic Reactions “Energy Out”
Chemical reactions that release energy
Cellular respiration – breaking bonds of sugar to release energy

13. Progress of the reaction
Fig. 8-6a
Reactants
Amount of
energy
released
(∆G < 0)
Free energy
Energy
Products
Figure 8.6a Free energy changes (ΔG) in exergonic and endergonic reactions
Progress of the reaction
(a) Exergonic reaction: energy released

14. Chemical Reactions Cellular Metabolism
Sum of all exergonic and endergonic reactions in a cell
Anabolic Pathways – consume energy to build complex molecules from simple ones (endergonic)
Catabolic Pathways – release energy by breaking down complex molecules into simple ones (exergonic)

15. Chemical Reactions Energy Coupling
The use of energy released from exergonic reactions to drive essential endergonic reactions

16. Adenosine Triphosphate
Energy currency of the cell
Powers nearly all cellular work through energy coupling reactions
Phosphate groups
Ribose
Adenine

17. H2O P P P Adenosine triphosphate (ATP) P + P P + Energy
Fig. 8-9 P P P
Adenosine triphosphate (ATP)
H2O
Figure 8.9 The hydrolysis of ATP P + P P +
Energy i
Inorganic phosphate
Adenosine diphosphate (ADP)

18. ATP – ADP Cycle H2O Energy for cellular work (endergonic,+
Energy from
catabolism (exergonic,
energy-releasing
processes)
Energy for cellular
work (endergonic,
energy-consuming
ATP
H2O
Phosphorylation - adding a phosphate

19. Cells use ATP
Three types of cellular work that are powered by hydrolysis of ATP
Cell Transport – Bringing materials into cells
Mechanical Work – muscle contractions
Chemical Work – macromolecule synthesis

20. Fig. 8-11 Membrane protein Solute Solute transported i Vesicle
(a) Transport work: ATP phosphorylates
transport proteins
ADP
ATP + P i
Vesicle
Cytoskeletal track
Figure 8.11 How ATP drives transport and mechanical work
ATP
Motor protein
Protein moved
(b) Mechanical work: ATP binds noncovalently
to motor proteins, then is hydrolyzed