Introduction to Biophysics and Life PDF

INTRODUCTION TO BIOPHYSICS/ LIFE AND ITS PHYSICAL BASIS Jonas T. Hingco Instructor College of Arts and Sciences  At the end of the lesson, the students are expected to: Define the scope of biophysics...

INTRODUCTION TO BIOPHYSICS/ LIFE AND ITS PHYSICAL BASIS Jonas T. Hingco Instructor College of Arts and Sciences  At the end of the lesson, the students are expected to: Define the scope of biophysics Describe what is life based on physical perspective LEARNING OUTCOMES Describe the mechanism of how organisms obtain energy and where did it came from  OUTLINE What is Biophysics Biophysics: The Bridging Science Scope of Biophysics Life: It's Characteristics Life: Thermodynamic Features Thermodynamics: Development and its Laws Free Energy Change Enthalpy and Entropy  It is a branch of science concerned with the application of physical principles and methods to biological problems (https://www.merriam- webster.com/) WHAT IS BIOPHYSICS? It is the field that applies the theories and methods of physics to understand how biological systems work (https://www.biophysics.org) BIOPHYSICS: What makes THE biophysics a bridging BRIDGING SCIENCE science?  SCOPE OF BIOPHYSICS Data Analysis and Structure Neuroscience Computer Bioengineering, Modelling Nanotechnology and Biomaterials Molecules in Medical Motion Applications LIFE: A PHYSICAL PERSPECTIVE  LIFE: ITS CHARACTERISTICS Sensitivity or Response to Reproduction Stimuli Regulation Homeostasis Energy Processing LIFE: THERMODYNAMIC Open System FEATURES Capable of Doing Work Organizes Itself Requires Energy  THERMODYNAMICS: IT'S RELATION TO ORGANISMS Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. It describes how thermal energy is converted to and from other forms of energy and how it affects matter. (https://www.livescience.com) Exchanges of energy that take place in living creatures must follow the laws of thermodynamics DEVELOPMENT OF THERMODYNAMICS Thomas Savery: Heat James Watt: machine to raise water Modern steam from a mine. engine design. Thomas Newcomen: Blacksmith improved Savery pump. The quest to improve this technology led to the development of thermodynamics  FO RMS OF ENERGY  In thermodynamics, the universe is divided into the system of interest and the 1 S T L AW rest of the universe (the OF THERMO surroundings). DY N A M I C S Heat (q) can flow into the system. Work (w) can be done by the system on the surroundings. “Internal Energy” = U First Law: U = q-w  ZEROTH LAW Two states of material A both in thermal equilibrium with material B are in thermal equilibrium with each other and share a property called temperature related to their “hotness”. Temperature was first measured using an easily purified material (Hg) having a thermal expansivity [(δV/δT)P] that was fairly constant with temperature. Celsius’ temperature scale was defined by dividing the change in Hg volume between the melting of ice and the boiling of water (1 atm pressure) by 100. Kelvin’s scale was defined by the statistical mechanical properties of an ideal gas, with the units being the same used by Celsius, thus fixing the Boltzmann constant at its current value. Kelvin’s scale had the advantage that T=0 when molecular motion stopped.  EXAMPLE OF ENERGY CONVERSION How do we apply the first law of thermodynamics in biological systems?  The “perfect” steam engine is not possible. It is impossible to convert heat completely into work during a real (irreversible) process. A system undergoing the process: state A ➞B ➞A exchanges no NET 2 N D L AW work or heat with its environment if it follows a Reversible Path. OF THERMO DY N A M I C S  EXAMPLE How do we apply the second law of thermodynamics in biological systems?  FREE ENERGY CHANGE A living system’s free energy Is energy that can do work under cellular conditions The change in free energy, ∆G during a biological process Is related directly to the enthalpy change (∆H) and the change in entropy ENTHALPY: CHANGING VARIABLES Enthalpy is the sum of the internal energy added to the product of the pressure and volume of the system. The enthalpy, ΔH=ΔE+PΔV  Entropy is the measure of disorder in a thermodynamic system. It is represented ENTROPY as ΔS=ΔQ/T where Q is the heat content and T is the temperature. Difference Between Enthalpy and Entropy Enthalpy Entropy Enthalpy is a kind of energy Entropy is a property It is the sum of internal energy and flows It is the measurement of the randomness of energy molecules It is denoted by symbol H It is denoted by symbol S It was termed by a scientist named Heike It was termed by a scientist named Rudolf Kamerlingh Onnes Clausius It unit is Jmol−1 It unit is JK−1 It related is applicable in standard conditions It does not have any limits or conditions. The system favor minimum enthalpy The system favor maximum entropy  FREE ENERGY, STABILITY, AND EQUILIBRIUM Organisms live at the At maximum stability The system is at equilibrium expense of free energy During a spontaneous change Free energy decreases and the stability of a system increases  Understanding the mechanisms of how organisms obtain energy CONCLUSION and where it came from is integral in identifying the very basis of the existence of life. THANK YOU!!!