Presentation on explaining the parts snout thr energy in biosystems

1. Concept of energy in
biosystems

2. Metabolism
► Metabolism is the assembly of biochemical reactions which are employed by
the organisms for the synthesis of cell materials and for the utilization of
energy from their environments.
► Metabolism is a highly integrated network of chemical reactions in which
multienzymes systems co-operate.

3. Metabolism has following functions
► To obtain chemical energy from the degradation of energy rich nutrients or
from captured solar energy
► To convert nutrient molecules into precursors of cell macromolecules
► To assemble these precursors into proteins, lipids, polysaccharides, nucleic
acids and other cell components
► To form and degrade biomolecules required in specialized functions of cells

4. Metabolic processes/metabolism
Catabolism
The processes whose major function is
the generation of chemical energy in
the forms suitable for the mechanical
and chemical processes of the cells are
termed as catabolism.
Anabolism
The processes which utilize energy generated
by catabolism for the biosynthesis of cell
components are termed as anabolism.

5. ► The various activities powered by catabolism include mechanical movement,
growth, reproduction, elimination of wastes etc.

6. ATP-universal currency of free energy in
biological systems
► Living things require a continual input of free energy for different purposes.
The free energy required for different processes is obtained from the
environment.
► Chemotrophs obtain this energy by oxidation of food stuff and phototrophs
obtain it by trapping light energy.
► Part of the free energy derived from the above sources is transformed into a
special form before it is utilized for the biological purposes. This special
carrier of free energy is adenosine triphosphate (ATP)

7. Structure of ATP
Adenine
D-Ribose
AMP(adenosine monophosphate
ADP(adenosine diphosphate)
ATP

8. ► ATP is a nucleotide consisting of an adenine, ribose sugar and a triphosphate unit.
► ATP is an energy rich molecule because its triphosphate unit contains 2 phosphoanhydride
bonds. A large amount of energy is liberated when ATP is hydrolysed to ADP and orthophosphate
(Pi) or when ATP is hydrolysed to AMP and pyrophosphate (PPi)
► ATP + H2
O ADP + Pi + H+
G0
’ = -7.3 Kcal
► ATP + H2
O AMP + PPi + H+
G0
’ = -7.3 Kcal
► ATP is continuously formed and consumed. ATP serves as the principal immediate donor of free
energy rather than as a long term storage form of energy.

9. ATP-ADP cycle
► Free energy liberated in the hydrolysis of ATP is utilized to drive the reactions
which require an input of free energy.
► In contrast, ATP is formed from ADP and Pi when fuel molecules are oxidized
in chemotrophs or when sunlight is trapped by phototrophs.
► This ATP-ADP cycle is the fundamental mode of energy exchange in biological
systems.

10. Electron carriers in the oxidation of fuel
molecules
► NADH ( NAD+
► FADH2
FAD