1 / 48

Introductory thoughts….

Introductory thoughts…. You should be familiar with Blackboard site Visit at least three times / week Download and print notes? Questions of the Week!!! Keep current!!! Do not fall behind!. More thoughts…. Math Bench availability will be announced when it is ready

edan-mccoy
Download Presentation

Introductory thoughts….

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introductory thoughts…. • You should be familiar with Blackboard site • Visit at least three times / week • Download and print notes? • Questions of the Week!!! • Keep current!!! Do not fall behind!

  2. More thoughts… • Math Bench availability will be announced when it is ready • Who do you contact if you have Math Bench problems? • Reminder about Discussion Board & Message functions on Blackboard • Study Questions for lectures 2 & 3 will be posted under Course Documents

  3. a few words of friendly advice….

  4. Avoid bad habits...

  5. Thermodynamics: • How all organisms get the job done.

  6. Energy: The ability to do work or supply heat (page 30)

  7. Wikipedia.com

  8. Why talk about energy now?

  9. Energy and Evolution All organisms require a source of energy to combat entropy and maintain an ordered system.

  10. Energy and Evolution Organisms are able to inhabit an environment by evolving a means of utilizing the energy source(s) available there.

  11. Energy and Evolution We will begin by examining energy and the physical laws that describe and govern its acquisition and use.

  12. One or more of these organisms must capture energy from this environment.

  13. Tubeworm, Riftia Symbiotic bacterium, Thiovulum

  14. Riftia • Has a unique hemoglobin that takes H2S from the environment and delivers it to the symbiotic Thiovulum • 2H2S + O2 ---> 2So +2 H2O + energy • How do these worms and other organisms capture or use this energy?

  15. http://www.divediscover.whoi.edu/vents/biology.html

  16. Energy Acquisition

  17. Summary:Organisms obtain useful energy from light or by oxidizing substrate molecules found in the environment

  18. Energy: potential& kinetic

  19. Fig 2.15

  20. Fig 2.16

  21. Types of Work • Synthetic • Mechanical • Concentration • Electrical • Heat production • Bioluminescence

  22. 1st Law of Thermodynamics: Energy cannot be created or destroyed, but only transferred and transformed (page 31) Efficiency is the thing for organisms!

  23. First Law of Thermodynamics • Life’s challenge – transform available energy into useful forms at the right places and at the right times • 1st Law describes energy interconversions • 1st Law specifies energy balances, not reaction direction or rate www.wildnetafrica.com

  24. 2nd Law of Thermodynamics: Entropy is always increasing in a isolated system (page 32)

  25. magnonel.guild.net/~schwern/talks/ Refactoring/slides/slide007.html

  26. and now let us examineone of the only significant events to occur in the great state of New Jersey!

  27. 7:25 PM on 6 May 1937

  28. Explosion of H2 Gas: 2 H2 + O2 ----> 2 H2O

  29. What do you know about that reaction from experience? • BOOM! • Light • Heat • Stable product • EXACTLY how did it occur? • Sharing of electrons in new bonds • Requires energy of activation to excite the electrons

  30. Fig 3.21 2 H2 + O2 2 H2O

  31. Enthalpy: H • H is the energy stored in the system or a molecule • Heat content of bonds in a compound • DH = Hproducts - Hreactants • When DH is negative, heat is given off exothermic • When DH is positive, endothermic

  32. 2nd Law of Thermodynamics: Entropy is always increasing in a isolated system (page 32) Life is all about combating the inevitable increase in Entropy!

  33. Two factors determine the spontaneity of a reaction: • Enthalpy: DH (or energy released or required) • Entropy: DS (increase or decrease in order of system) • The spontaneity of a reaction is expressed as the Gibbs Free Energy or DG (the energy available to do work)

  34. Does this reaction occur?Does it occur spontaneously? • Entropy (S) : is it increasing? • Enthalpy (H): is it giving off heat energy? G = H - TS G is Gibbs Free Energy

  35. Free Energy • Will the following reaction occur? C6H12O6 + 6O2 ---> 6CO2 + 6 H2O + energy G or Gibbs Free Energy is negative for this reaction - thus it will be spontaneous

  36. Gibbs Free Energyfor a spontaneous reaction DG = DH - T DS Negative & exothermic Positive & More disordered

  37. Glucose + 6O2 ----> 6CO2 + 6 H2Oor2 H2 + O2 ----> 2 H2OorCH4 + 2O2 ----> CO2 + 2H2O DH is negative (heat energy is released !) Reaction is exothermic

  38. Glucose + 6 O2 <---- 6 CO2 + 6 H2O DH is Positive Entropy is decreasing ! Reaction is endothermic

  39. Fig 2.18b

  40. Summary: organisms utilize redox reactions with - G (metabolism) to produce high energy electrons.

  41. Fig 2.20: burning methane (CH4)

  42. Thinking about oxidation and reduction of Carbon compounds: (CH2O)6 + 6O2 <---> 6CO2 + 6H2O Carbon is OXIDIZED loses electrons Oxygen in REDUCED gains electrons

  43. This table is the POINT of this topic! Energy Sources for Bacteria and Archaea

  44. Summary: Reactions of Living Organisms: C6H12O6 <---> 6CO2 + 6 H2O • To the right, energy is liberated and carbon (C) loses electrons (and protons) and is thus oxidized • To the left, energy is required, C gains electrons (and protons) and is reduced

  45. Summary:Organisms obtain useful energy from light or by oxidizing substrate molecules found in the environment

More Related