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
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
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.
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?
