chambers31 - BIOENERGETICS BIOENERGETICS Reading: q Harpers...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
BIOENERGETICS BIOENERGETICS Reading: Harper’s Biochemistry pp. 123-129 Lehninger Principles of Biochemistry 3rd Ed. pp. 485-522
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
OBJECTIVES OBJECTIVES To gain an understanding of concepts used to deal with energy flow in living organisms. To understand the following terms and concepts 1. Enthalpy 2. Entropy 3. Free Energy 4. Bioenergetic coupling of chemical reactions 5. Additivity of free energy changes 6. Relationship between standard free energy and equilibrium constant 7. Role of ATP as energy currency of cell
Background image of page 2
Bioenergetics- Biochemical Bioenergetics- Biochemical Thermodynamics Thermodynamics Quantitative study of the energy transductions that occur in living cells, and of the nature and function of the chemical processes underlying these transductions Provides underlying principles to explain why some reactions may occur while other do not Non-biological systems may use heat energy to perform work, whereas biological systems are essentially isothermic and use chemical energy to power living processes
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Biomedical Importance of Bioenergetics Biomedical Importance of Bioenergetics Fuel is required to provide energy for normal processes, so understanding energy production and utilization is fundamental to understanding normal nutrition and metabolism Starvation - occurs when available energy reserves are depleted Certain forms of malnutrition are associated with energy imbalance e.g. marasmus- wasting disease due to insufficient energy and protein intake Excess storage of surplus energy results in obesity which can have negative effects on health
Background image of page 4
Gibbs Free Energy Change ( Gibbs Free Energy Change ( G) G) G is that portion of the total energy change in a system that is available for doing work - it is the useful energy When a reaction proceeds with a release of free energy (i.e. the system changes so as to possess less free energy), the free energy change, G, has a negative value and the reaction is said to be exergonic In endogonic reactions, the system gains energy and G is positive Units of G - joules/mole (J/mol) - calories/mole (cal/mol)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Enthalpy, H Enthalpy, H Enthalpy is the heat content of the reacting system It reflects the number and kinds of chemical bonds in the reactants and products When a chemical reaction releases heat, it is said to be exothermic - the heat content of the products is less than that of the reactants and by convention, H has a negative value Reacting systems that take up heat from their surroundings are endothermic and have positive value of H Units of H - joules/mole (J/mol) - calories/mole (cal/mol)
Background image of page 6
Entropy, S Entropy, S Entropy is a quantitative expression for the randomness or disorder of a system When the products of a reaction are less complex and more disordered than the reactants, the reaction is said to proceed with a gain in entropy Units of S - J/mol·K - cal/mol·K K= units of absolute temperature (25 ° C = 298K)
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Entropy, S
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 33

chambers31 - BIOENERGETICS BIOENERGETICS Reading: q Harpers...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online