enzymes n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Enzymes PowerPoint Presentation
Download Presentation
Enzymes

Loading in 2 Seconds...

play fullscreen
1 / 25

Enzymes - PowerPoint PPT Presentation


  • 118 Views
  • Uploaded on

Enzymes. Energetics. First Law of Thermodynamics – energy cannot be created or destroyed, it can only change forms . Second Law of Thermodynamics – (potential energy transformation into heat or other random molecular motion) Entropy (disorder) is continuously increasing.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Enzymes


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Enzymes

    2. Energetics • First Law of Thermodynamics – energy cannot be created or destroyed, it can only change forms

    3. Second Law of Thermodynamics – (potential energy transformation into heat or other random molecular motion) Entropy (disorder) is continuously increasing

    4. Catabolism – metabolic reactions that result in the breakdown of complex molecules into simple compounds, usually with the release of energy • Anabolism – Those chemical reactions involved in biosynthesis, usually requires the input of energy

    5. Free Energy • The amount of energy available to make or break chemical bonds (the amount of energy available to do work)

    6. Endergonic reactions – those chemical reactions that require an input of energy and do not proceed spontaneously. • productscontain more free energythan the reactants

    7. Exergonic reactions – those chemical reactions that proceed spontaneously • products contain less free energy than the reactants; energy is given off as heat. • Most require an input of energy to get started (activation energy)

    8. The amount of activation energy can be lowered using catalysts (substances that lower the amount of activation energy by stressing chemical bonds) • Ex: enzymes

    9. Enzymes • Enzymes (biological catalysts) are very specific types of functional proteins. • Act as catalysts in biological systems (help mediate chemical activity)

    10. Enzymes are “substrate specific”; one enzyme for each type of substrate • Enzymes end in “ase” • Enzymes are reusable

    11. Enzymes work by lowering the activation energy needed for chemical reactions to occur • Enzymes have an active site to which the substrate bonds forming the “enzyme-substrate complex. Any change in this site will render the enzyme inactive

    12. Induced Fit

    13. Operate in a very narrow pH, temperature and ionic range. • varies from enzyme to enzyme; ex: enzymes in stomach vs. enzymes in blood; enzymes of the bacteria in thermal vents of Pacific vs. most other bacterial enzymes

    14. Factors Affecting Enzyme Activity: • Temperature: Optimum vs. Denaturation • pH • Salinity

    15. Inhibitors • Competitive: a substance that competes with the substrate for the same binding site. Ex: isopropyl and ethyl alcohol

    16. Noncompetitive: substance that binds to an alternative site (allosteric site) on the enzyme, changing its shape, and preventing it from binding to the substrate

    17. Allosteric inhibitors – act as “on/off” switches; bind to allosteric site and reduce enzyme activity • Allosteric activators – bind to allosteric site and increase enzyme activity by keeping enzyme active

    18. Cofactors – minerals that aid enzyme activity • Coenzmye – nonprotein, organic molecule that aids enzyme activity; vitamins

    19. Feedback Inhibition • Final product in a biochemical pathway becomes an allosteric effector on one of the molecules in the pathway and stops the process. • Ex: glucose and insulin