Презентация на тему Theoretical principles of bioenergetics

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

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.

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.

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.

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

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.

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

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

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.

The second law of thermodynamics:

In isolated systems processes occur spontaneously on condition of entropy increase.

Т∆S = ∆Q
(connected energy)

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