Theoretical principles of bioenergetics

1. Zaporizhzhya State Medical University Analytical Chemistry Department THEORETICAL PRINCIPLES OF BIOENERGETICS Lecturer: Monaykina Yulia Vitalievna 2016

2.

Chemical thermodynamics studies the
conditions of chemical systems stability and
the laws under which they change to achieve
maximum stability – the state of chemical
equilibrium.
It allows foreseeing a definite chemical
reaction proceeding in a given chemical
system, as well as the direction of equilibrium
shift in the system in accordance with the
change of temperature, pressure and agents
concentration.

3.

Bioenergetics is a field of
thermodynamics that deals with
biosystems.
The energy of reactions is studied by the
branch of thermodynamics called
thermochemistry or chemical
thermodynamics.

4.

Thermodynamic system – is a body or a
group of bodies, which interact whith
each other and are separated from the
environment by a real or imaginary
surface.

5.

Isolated system is a system which exchanges
neither mass nor energy with environment.
Closed system is a system which exchanges
energy but doesn’t exchange mass with
environment.
Open system is a system which exchanges both
mass and energy with environment.
All biological systems are open systems

6.

Homogeneous system is a system, which
consists of only one phase.
Heterogeneous system consists of several
phases.
Phase is a part of a system, which is
separated by the interfacial area while its
crossing the properties change stepwise.

7.

The first law of thermodynamics
(determines the relationship between internal energy, heat and work):
An increase of the internal energy of a system is
equal to the heat which is received by the system
from the outside except for the work produced by
the system against external forces:
∆U = Q – A

8.

Enthalpy
is the function of state the
increment of which is equal to
heat which the system gets in
isobaric process.

9.

Hess’s law
The heat of a reaction is independent of the
way, in which this reaction occurs, and only
depends upon the initial and final states of a
system.

10.

The second law of
thermodynamics:
In isolated systems processes occur
spontaneously on condition of entropy
increase.
Т∆S = ∆Q
(connected energy)

11.

Living organisms
are open systems that exchange their
matter and energy with the
environment.