1. The document discusses the ATP-ADP cycle and how ATP is used as the main energy currency in cells. ATP stores chemical energy from breaking down glucose, fats, and proteins that is then released through hydrolysis to power cellular work like transport, mechanical movement, and chemical reactions. 2. Autotrophs like plants generate ATP through photosynthesis while heterotrophs obtain ATP indirectly by consuming autotrophs or other organisms. The sun is the ultimate source of energy entering ecosystems. 3. ATP is regenerated as energy from food breakdown is used to add a phosphate back to ADP, and energy is released when phosphate is removed from ATP, powering cellular work processes.

1. Energy Transformation:
ATP – ADP Cycle

2. Explicate the couple reaction processes and
describe the role of ATP in energy coupling and
transfer
The learners should be able to:
1. Define ATP and ADP,
2. Describe how ATP works in cellular process, and
3. Explain coupled reaction processes and
describe the role of ATP in energy coupling and
transfer.

3.  Living cells require energy from outside sources
 Energy flows into an ecosystem as sunlight and
leaves as heat
 Photosynthesis generates O2 and organic
molecules, which are used in cellular respiration
 Cells use chemical energy stored in organic
molecules to regenerate ATP
Overview: Life Is Work

4. ATP-ADP Cycle

5. The Flow of Energy
• All life on earth depends on
the flow of energy through
ecosystems
• All energy on the earth
ultimately comes from the
sun

6. Organisms are classified according to their
energy source
These are the:
AUTOTROPHS
• Photoautotrophs
• Chemoautotrophs
HETEROTROPHS
• Carnivores
• Herbivores
• Omnivores
• Scavengers
• Decomposers
• Detritivores

7. Autotrophs
• organisms capable of
making their own
food.
• plants are
photoautotrophs
• they use light energy
from the sun to
produce glucose
(sugar)

8. Heterotrophs
• organisms not capable
of making their own
food
• they are consumers of
the biosphere
• they must eat plants, or
other animals who eat
plants to acquire
indirectly the energy
from the sun

9. Pyramid of Energy

10. What is the energy currency of the
cells of autotrophs and heterotrophs?
The activities of the cell are powered by a
chemical fuel called adenosine triphosphate
(also known as ATP).

11. Adenosine Triphosphate
The common energy
currency of cells.
With one big
molecule that is
made of 5 smaller
molecules bonded
together.
Adenosine Tri-phosphate

12. How energy is released from ATP?
• ATP transfer energy from the
breakdown of food molecules
to cell function.
• Energy is released when
phosphate group (P) is
removed
• ADP is charge into ATP when
phosphate group (P) is added.

13. Light
energy
ECOSYSTEM
Photosynthesis
in chloroplasts
CO2 + H2O
Cellular respiration
in mitochondria
Organic
molecules
+ O2
ATP powers most cellular work
Heat
energy
ATP

14. Redox Reactions: Oxidation and Reduction
 The transfer of electrons during chemical
reactions releases energy stored in organic
molecules
 This released energy is ultimately used to
synthesize ATP

15.  The three types of cellular work are:
 transport
 mechanical
 chemical
 Each is powered by the hydrolysis of ATP
 In the cell, the energy from the exergonic
reaction of ATP hydrolysis can be used to
drive an endergonic reaction
How ATP Performs Work?

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

17. Key concepts of ATP/ADP Cycle
1. ATP contains MORE energy than ADP because it
has more bonds.
2. When a phosphate is REMOVED energy is
RELEASED.
3. When a phosphate is ADDED energy is NEEDED.

18. ATP-ADP Cycle: Carbohydrates
• Energy: up to 36 ATP
molecules (1 glucose)
• Details:
• Most commonly
broken down to
make ATP
• Not stored in large
amounts

19. • Energy: about 146 ATP
molecules
(triglyceride)
• Details:
• Lipids store the most
energy
• 80% of the energy in
our body
ATP-ADP Cycle: Fats/Lipids

20. • Energy: about 36 ATP
molecules BUT…
• Details:
• Proteins are least
likely to be broken
down to make ATP,
• Amino acids not
usually needed for
energy
ATP-ADP Cycle: Proteins

21. Energy Content of Biomolecules
MOLECULES ENERGY
Carbohydrates 4 calories per mg
Lipid 9 calories per mg
Protein 4 calories per mg

22. Learning Check
1. Where does plants get energy to produce its
own food?
2. Consumers are also termed as .
3. When does ATP release its stored energy?
4. What molecule will be formed if 1 molecule of
phosphate will be released?
5. Which of the biomolecules possessed greater
amount of energy?

23. Answer
1.Sun
2.Heterotrophs
3.When 1 of the phosphorus is broken and
released
4.ADP
5.Lipids/Fats