9.photosynthesis.6.pdf - Lecture 9 – Photosynthesis...

This preview shows page 1 - 3 out of 7 pages.

1Lecture 9PhotosynthesisBIOL1010General BiologyLaramie CountyCommunity CollegeOverviewRadiation energyPhotosynthesisLife on earth is solar poweredPlants use a process called photosynthesis to capturelight energy from the sun and convert it to chemicalenergy stored in sugars and other organic moleculesPhotosynthesis is counteredby cellular respirationThey use each othersproducts as substrateshttps://youtu.be/JJxZH_Y5D4sBackgroundLight is radiation from the sun in theelectromagnetic spectrumMeasured aswavelength(λ)Visible light iseither reflected,transmitted orabsorbed by anygiven surface
2Pigments are able to absorbspecific wavelengths of lightChlorophyllis the mainpigment in photosynthesisChlorophyll mainly absorbs light in theblueandredparts of the spectrumTwo forms (a and b) are slightly differentNo absorption in green and yellowDoes thismake sense?Plants also haveaccessory pigments:increase the range oflight wavelengths thatcan be used inphotosynthesiscan protect the plantfrom excess lightocarotenoidsHow does absorption work?Reminder- each atom has multiple valenceshellsThe further from the nucleus, the greater theenergyThird shell (highest energylevel)Second shell (higherenergy level)EnergyabsorbedFirst shell (lowest energylevel)AtomicnucleusEnergylostA chlorophyll molecule absorbs a particle oflight, called aphoton, which excites anelectron to a higher electron shell giving itgreater potential energyHeatExcitedstatePhotonGroundstatePhoton(fluorescence)Energy of electroneChlorophyll

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 7 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Summer
Professor
NoProfessor

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture