The presentation covered cell bioenergetics, including the definition of bioenergetics as the study of energy relationships in living organisms. It discussed types of reactions and major bioenergetic processes like glycolysis, gluconeogenesis, the citric acid cycle, ketosis, oxidative phosphorylation, and photosynthesis. It also explained the three mechanisms of ATP generation in bacteria: substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation. Finally, it defined Gibbs free energy and described how it relates to the entropy and enthalpy of a system to determine the spontaneity of chemical reactions.

1. Presentation on
Cell Bioenergetics

2. Tropics of Discussed:
1. What is Bioenergetics ?
2. Types of reactions.
3. Examples of major
bioenergetics processes.
4. Process of ATP generation.
5. Free energy.

3. DESCRIBE about
Bioenergetics
• Bioenergetics is the part of
biochemistry concerned with
the energy involved in making
and breaking of chemical
bonds in the molecules found
in biological organisms. It can
also be defined as the study
of energy relationships and
energy transformations and
transductions in living
organisms.

4. Types of reactions.

5. Examples of major bioenergetics
processes.
Glycolysis is the process of breaking down glucose into pyruvate, producing two molecules
of ATP (per 1 molecule of glucose) in the process.
Gluconeogenesis is the opposite of glycolysis; when the cell's energy charge is low (the
concentration of ADP is higher than that of ATP), the cell must synthesize glucose from
carbon- containing biomolecules such as proteins, amino acids, fats, pyruvate, etc.
The citric acid cycle is a process of cellular respiration in which acetyl coenzyme,
A synthesized from pyruvate dehydrogenase, is first reacted with oxaloacetate to
yield citrate.
Ketosis is a metabolic process whereby ketone bodies are used by the cell for energy. Cells
often turn to ketosis as a source of energy when glucose levels are low; e.g. during
starvation.

6. Examples of major bioenergetics
processes.
Oxidative phosphorylation is the process where the energy stored in the
relatively weak double bonds of O2 is released in a controlled manner in
the electron transport chain. This difference in proton concentration
between the mitochondrial matrix and inner membrane space is used to
drive ATP synthesis via ATP synthase.
Photosynthesis, another major bioenergetic process, is the metabolic
pathway used by plants in which solar energy is used to synthesize
glucose from carbon dioxide and water. This reaction takes place in
the chloroplast. After glucose is synthesized, the plant cell can
undergo photophosphorylation to produce ATP.

7. Process of ATP
generation
Bacteria Uses Three
Mechanisms of
Phosphorylation to
generate ATP from ADP

8. ATP Process Info-
Graphic
21
3
1. Substrate level
phosphorylation.
C-C-C-P+ ADP C-C-C+ ATP
In this mechanism a high
energy photosphate from a
phosphorylated substrate is
directly transferred to ADP
2. Oxidative
Phosphorylation.
ATP generation duting ETC.
3.
Photophosphorylation
Occurs in Phototrophs.
Derive ATP using radiant
energy of the sun.
These ATP are then
utilized to synthesize
mainly glucose.

9. Free energy.

12. Gibbs free energy combines enthalpy
and entropy into a single value.
Gibbs free energy is the energy
associated with a chemical reaction that
can do useful work. It equals the
enthalpy minus the product of the
temperature and entropy of the system.
G = H – TS
At constant temperature,
ΔG = ΔH – TΔS
ΔG predicts the direction of a chemical
reaction. If ΔG is negative, then the
reaction is spontaneous. If ΔG is
positive, then the reaction is non-
spontaneous.

17. Name ID
Sabrina Sharmin Suchi 193 012 031
Mst. Nasrin Akter 193 014 031
Md. Asadujjaman 193 015 031
Md. Azizul Haque 193 016 031
Md. Arafat Rahman Parvez 193 017 031
Sirajum Monira 193 018 031
Md. Jafor Iqbal 193 020 031
PRESENTED BY

18. REFERENCES
1. https://www.grc.nasa.gov/www/Wright/airplane/thermo1.html
3. https://en.wikipedia.org/wiki/Bioenergetics
4. https://socratic.org/questions/how-is-gibbs-free-energy-
related-to-enthalpy-and-entropy
5. https://pt.slideshare.net/simonandisa/entropy-and-the-2nd-
law-12173544/11
2. https://www.grc.nasa.gov/www/k-12/airplane/thermo2.html

19. Thank You!
Any Question?