After reading this slideshare u will be able to answer questions related to role of ATP in bioenergetics.... so good luck guys...

2. HIRA IFTIKHAR
ROLL NO: 332
B.S HONS CHEMISTRY

3. ATP(adenosine
triphosphate)
Role of ATP in
Bioenergetics

4. RUN DOWN
In this lecture we will discuss:
 Definition
 Properties
 Chemical Structure
 ATP production
 How ATP gives energy?
 Sources of ATP
 Role of ATP in cells
 Conclusion

5. Definition
 Adenosine triphosphate, or ATP for short, is the energy
currency of life. ATP is a high-energy molecule found in
every cell. Its job is to store and supply the cell with needed
energy.

6. Properties
Chemical formula C10H16N5O13P3
Molar mass 507.18 g/mol
Density 1.04 g/cm
3
(disodium salt)
Melting point 187 °C (369 °F; 460 K) disodium salt;
decomposes
Acidity (pK 6.5

7. Chemical Structure
 The ATP molecule is composed of three components. At the
centre is a sugar molecule, ribose (the same sugar that forms
the basis of RNA). Attached to one side of this is a base (a
group consisting of linked rings of carbon and nitrogen
atoms); in this case the base is adenine. The other side of
the sugar is attached to a string of phosphate groups. These
phosphates are the key to the activity of ATP.

8. How ATP gives energy?
The entire reaction that turns ATP into energy is a bit complicated, but
here is a good summary:
 Chemically, ATP is an adenine nucleotide bound to three phosphates.
 There is a lot of energy stored in the bond between the second and
third phosphate groups that can be used to fuel chemical reactions.
 When a cell needs energy, it breaks this bond to form adenosine
diphosphate (ADP) and a free phosphate molecule.
 In some instances, the second phosphate group can also be broken to
form adenosine monophosphate (AMP).
 When the cell has excess energy, it stores this energy by forming ATP
from ADP and phosphate.
 ATP is required for the biochemical reactions involved in any muscle
contraction. As the work of the muscle increases, more and more ATP
gets consumed and must be replaced in order for the muscle to keep
moving

9. High energy bond
energy

11. Source of ATP
ATP comes from three different biochemical systems in the
muscle, in this order:
 Phosphagen system
 Anaerobic glycolysis
 Aerobic respiration

12. The Three Primary Energy Pathways
Phosphagen System
This system uses creatine phosphate (CP) and has a very rapid
rate of ATP production. . An enzyme called creatine kinase
removes the phosphate group from creatine phosphate and
transfers it to ADP to form ATP. The cell then turns ATP into ADP,
and then the phosphagen turns the ADP back into ATP. It is,
however, instantaneously available and is essential at the onset of
activity, as well as during short-term high-intensity activities lasting
about 1 to 30 seconds in duration, such as sprinting, weight-lifting
or throwing a ball.
Anaerobic Glycolysis
Anaerobic glycolysis does not require oxygen and uses the energy
contained in glucose for the formation of ATP. As an intermediate
pathway between the phosphagen and aerobic system, anaerobic
glycolysis can produce ATP quite rapidly for use during activities
requiring large bursts of energy over somewhat longer periods of
time (30 seconds to three minutes max.

13. Aerobic Glycolysis
This pathway requires oxygen to produce ATP, because
carbohydrates and fats are only burned in the presence of
oxygen. This pathway occurs in the mitochondria of the cell
and is used for activities requiring sustained energy production.
Aerobic glycolysis has a slow rate of ATP production and is
predominantly utilized during longer-duration, lower-intensity
activities after the phosphagen and anaerobic systems have
fatigued.

14. Role of ATP in cells
ATP finds use in several cellular processes. Some important
functions of ATP in the cell are briefly discussed below.
 Energy Source
 Active Transport
 Cell Signaling
 Muscle Contraction
 DNA synthesis
 Structural Maintenance
 Photosynthesis
 Reproduction
 Amino acid activation in protein synthesis

15. Energy source
 Cells require chemical energy for three general types of
tasks: to drive metabolic reactions that would not occur
automatically; to transport needed substances across
membranes; and to do mechanical work, such as moving
muscles.
 The phosphate tail of ATP is the actual power source which
the cell taps. Available energy is contained in the bonds
between the phosphates.

16. Active Transport
ATP plays a critical role in the transport of macromolecules
such as proteins and lipids into and out of the cell. The
hydrolysis of ATP provides the required energy for active
transport mechanisms to carry such molecules across a
concentration gradient. Transport of molecules into the cell is
called endocytosis whilst transport out of the cell is known as
exocytosis.

17. Diagrammatic View(Na+,K+ pump)

18. Muscle Contraction
 ATP is critical for the contraction of muscles; it binds to
myosin to provide energy and facilitate its binding to actin to
form a cross-bridge. ADP and phosphate are then released
and a new ATP molecule binds to myosin. This breaks the
cross-bridge between myosin and actin filaments, thereby
releasing myosin for the next contraction.

19. Diagrammatic View
ATP First ATP

20. Cell Signaling
 ATP has key functions both in intracellular and extracellular
signaling. It is easily recognized by purinergic receptors in
mammalian tissues - its release from synapses and axons
activates purinergic receptors that modulate calcium and
cyclic AMP levels inside the cell.
 In the central nervous system, adenosine modulates neural
development, the control of immune systems, and of
neuron/glial signaling.
 ATP is also involved in signal transduction - its phosphate
groups are used up by kinases in phosphate transfer
reactions which activate a cascade of protein kinase
reactions.

21. Diagrammatic view

22. DNA and RNA synthesis
 During DNA synthesis, ribonucleotide reductase (RNR)
reduces the sugar residue from ribonucleoside diphosphates
to form deoxyribonucleoside diphosphates such as dADP.
 Thus, RNR regulation helps keep the balance of
deoxynucleotides (dNTPs) in the cell. Low concentrations of
dNTPs inhibit DNA synthesis and repair whilst high levels are
shown to be mutagenic because DNA polymerase tends to
add the wrong dNTP during DNA synthesis.
 The adenosine from ATP is a building block of RNA and is
directly added to RNA molecules during RNA synthesis by
RNA polymerases. The removal of pyrophosphate provides
the energy required for this reaction.

23. DNA synthesis

24. Structural maintenance
ATP plays a very important role in preserving the structure of
the cell by helping the assembly of the cytoskeletal elements. It
also supplies energy to the flagella and chromosomes to
maintain their appropriate functioning.

25. Photosynthesis
 In photosynthesis energy is transferred to ATP in the light-dependent stage
and the ATP is utilised during synthesis in the light-independent stage.ATP is
used in the Calvin cycle(dark reaction) of photosynthesis to incorporate
energy at various points…
 After the formation of 3-phosphoglycerate, ATP is used to reduce it into 1,3-
biphosphoglycerate and later ATP is used to regenerate the CO2 acceptor
(RuBP) by reacting with RuP (ribulose phosphate) here, three ATP
Molecules of ATP react with three molecules of RuP and a phosphate group
from each ATP is transferred to each RuP.. Ultimately RuP is converted into
RuBP(CO2 acceptor).

26. Calvin Cycle

27. Amino acid activation in protein
synthesis
 Amino acid activation refers to the attachment of an amino
acid to its Transfer RNA (tRNA).
 Aminoacyl transferase binds Adenosine triphosphate (ATP)
to amino acid, PP is released.
 Aminoacyl tRNA synthatase binds AMP-amino acid to tRNA.
The AMP is used in this step.
The coupling reaction proceeds in two steps:
aa + ATP ⟶ aa-AMP + PP, (pyrophosphate)
aa-AMP + tRNA ⟶ aa-tRNA + AMP

28. Amino acid activation

29. Reproduction
 Extracellular ATP is essential for the function of the
epididymis and spermatozoa, but ATP release in the
epididymis remains uncharacterized.
 In the epididymis, a small organ located downstream of the
testis where sperm acquire their fertilizing abilities,
extracellular ATP regulates transepithelial electrolyte and
water transport

30. Conclusion
 ATP is an intricate molecule that serves as an energy packet
for thousands of reactions that take place in the cells of most
organisms. Apart from humans, microorganisms also rely on
ATP for their energy needs.
 ATP is a highly efficient molecular machine with a rapid
turnover of energy that makes it suitable to meet the
changing energy demands of the body. An ATP molecule is
over 500 atomic mass units (AMUs).
 Even as evolutionists wonder about life before the complex
ATP molecule and alternatives to ATP, no other energy
source currently exists that can accurately respond to the
energy needs of the cell and carry out its crucial processes.

31. ATP is to the cell what
food is to you.
So , we can say that;

33. ANY
QUESTIONS?