BIOPHYSICS. Politechnika Łódzka, ul. Żeromskiego 116, Łódź, tel. (042)

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Radosław Witkowski
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1 BIOPHYSICS Prezentacja multimedialna współfinansowana przez Unię Europejską w ramach Europejskiego Funduszu Społecznego w projekcie pt. Innowacyjna dydaktyka bez ograniczeń - zintegrowany rozwój Politechniki Łódzkiej - zarządzanie Uczelnią, nowoczesna oferta edukacyjna i wzmacniania zdolności do zatrudniania osób niepełnosprawnych Politechnika Łódzka, ul. Żeromskiego 116, Łódź, tel. (042)

2 Biophysics 2 Lecture 2 Thermodynamics of open systems - information (2) Bogdan Walkowiak Department of Biophysics Institute of Materials Science and Engineering Technical University of Lodz

3 Thermodynamic Potentials and Stimulus Biophysics 3 Thermodynamic potential - it is a thermodynamic function, whose change in a reversible process is equal to a total work done by a system. Thermodynamic stimulus are defined as a difference between thermodynamic potentials of interacting thermodynamic systems

4 Thermodynamic Stimulus Biophysics 4 Thermodynamic stimulus Flow Temperature gradient (dt/dl) of heat Pressure gradient (dp/dl) of gas or fluid Concentration gradient (dc/dl) of matter Electric potential gradient (dv/dl) of current Fick s Law (diffusion) dn/dt = -DS (dc/dl) Fourier s Law (heat conduction) dq/dt = -ls (dt/dl) Ohm s Law (current conduction) dq/dt = -gs (dv/dl)

5 Biophysics 5 Substance Transport (1) Stream of mass an amount of substance of interest passing in the unit of time by a unit of surface positioned perpendicularly to the stream direction. source flow out J = c v (concentration multiplied by velocity) The derivative of the stream has two extreme values: For existing source (flow in): dj/dx >0 For existing receiver (flow out): dj/dx <0

6 Substance Transport (2) Thermodynamic Coupled Processes The flow velocity depends on the thermodynamic stimuli (thermodynamic force) causing the flow: Biophysics 6 v = w X where w is a proportionality coefficient thus: or: J = c w X J = L X where L is a coefficient of coupling (phenomenological coefficient) Generally for a multi-substance transport: n J i = SL ij X j j=1

7 Biophysics 7 Substance Transport (3) The last formula can be written as: J 1 = L 11 X 1 + L 12 X L 1n X n J 2 = L 21 X 1 + L 22 X L 2n X n.. J n = L n1 X 1 + L n2 X L nn X n Stream J m is coupled with the stimulus (force) X n only when value of L nm is different from 0

8 Biophysics 8 Substance Transport (an example of coupling)

9 Biophysics 9 Substance Transport (an example of coupling) J Na = L 11 (K + /Na + ATPaza)+L 12 (grad-dyf Na + )+L 13 (Ca 2+ /Na + exch) J ca = L 21 (Ca 2+ ATPaza)+L 22 (grad-dyf Ca 2+ )+L 23 (Ca 2+ /Na + exch) Forced by the K + /Na + pump (K + /Na + ATPase) gradient of Na + ions concentration makes driving force of coupled Na + - Ca 2+ ions transport.

10 Biophysics 10 The 2nd Principle of Thermodynamics in Living Organisms Entropy of metabolism ds i Entropy of exchange ds e = (ds e - ds e ) < 0 In the grow phase of organism ds i /dt < ds e /dt For the adult organism ds i /dt = ds e /dt For the ecosystem ds ekos = ds oto + ds org > 0

11 Maxwell's Demon Biophysics 11 Unknown author of the graphics

12 Maxwell's Demon Biophysics 12 An increase in disorder is associated with an appropriate increase of entropy Information can be converted into entropy and inversely Increasing information included in the system we can decrease entropy of the system, but entropy of environment must increase then Negative entropy we call negaentropy or information

13 Information Biophysics 13 Mathematical probability: number of favourable cases (coincidences) P = number of all possible cases (coincidences) Information I is a function of probability P I = f(p) Must be fulfilled condition: It means: I = I + I = f(p 1 ) + f(p 2 ) = f(p 1 P 2 ) I = K lnp (in bits K=-1/ln2) or I = k lnp (cal/k)

14 Flow of Information Biophysics 14 source signal signal signal recipient generator transmission receiver Sending a signal is related to decision-making, i.e. eliminating the state of uncertainty disturbances Rate of signal transmission: - modem bit/s - reading 45 bit/s - writing 16 bit/s - calculation 3 bit/s

15 Information Encoding Biophysics 15 Amplitude modulation binary code Frequency modulation interval code There are a huge diversity of ways for information encoding. All diplomatic correspondences and communications require to be encoded, and army forces also use coding process for information exchange. For example ENIGMA was the most famous encoding system used by German army during the 2 nd World War. This system was broken by Polish cryptologists. Simply spiking, every conversation uses selected language as a code for information passing.

16 Control of information flow Biophysics 16 Controlled system Feedback FEEDBACK positive feedback - chain reactions leading to system destruction (disintegration of uranium in nuclear weapon, blood clotting, microphone loudspeaker coupling) negative feedback - system control and stabilization (thermostat, WC-water reservoir, blood hemostasis (thrombosis and fibrinolysis)

17 System with negative feedback Biophysics 17 disturbance INPUT CONTROLLED SYSTEM OUTPUT RECEPTOR MEMORY ENERGIA EFEKTOR KOMPARATOR STANDARD AMPLIFIER P CONTROLLED PARAMETER TIME

18 Role of blood platelets in thrombosis Biophysics 18 Unknown author of the graphics

19 Order of Reaction Biophysics 19 Probability of reaction realization is proportional to substrate concentration and reaction rate constants Zero order: A A First order: A B Second order: A+B C J c = k 1 AB - k -1 C Third order: A+B+C D Example of third order p n + e + + n

20 Biophysics 20 Example of positive feedback (1) feedback

21 Biophysics 21 Example of positive feedback (2)

22 Biophysics 22 Example of positive feedback (3)

23 Biophysics 23 Example of positive feedback (4)

24 Biophysics 24 Example of positive feedback (5)

25 BIOPHYSICS Prezentacja multimedialna współfinansowana przez Unię Europejską w ramach Europejskiego Funduszu Społecznego w projekcie pt. Innowacyjna dydaktyka bez ograniczeń - zintegrowany rozwój Politechniki Łódzkiej - zarządzanie Uczelnią, nowoczesna oferta edukacyjna i wzmacniania zdolności do zatrudniania osób niepełnosprawnych Politechnika Łódzka, ul. Żeromskiego 116, Łódź, tel. (042)

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