Reading BIO NOTES

Reading BIO NOTES - :CapturingEnergy molecules 6CO...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 9-Photosynthesis: Capturing Energy Photosynthesis -light energy is converted into the stored chemical energy of organic  molecules  o 6CO_ + 6H_O                   C_H_O_ + 6O_ Photons -small particles or packets of energy (light is composed of photons) o When a molecule absorbs a photon of light energy, one of its electrons becomes  energized, electron shifts from a lower-energy atomic orbital to a higher one Visible Spectrum : 380-760nm, includes all the colors of the rainbow (humans can see  it) o Violet (has more energy) has the shortest wavelength & red has the longest  wavelength Ground State:  condition in which all of the atoms electrons are in their normal, lowest- energy levels o When an electron returns to ground state, its NRG dissipates as heat or as an  emission of light (fluorescence) of a longer wavelength than the absorbed light  Chloroplasts  lie mainly inside the leaf in the cells of the  mesophyll  (a layer of w/many  air spaces & a very high concentration of water vapor). The interior of the leaf  exchanges gases w/the outside through microscopic pores, called  stomata . Stroma:  inner membrane of the chloroplast (fluid-filled region) which contains most of  the enzymes required to produce carbohydrate molecules  Thylakoids:  (3 rd  system of membranes) an interconnected set of flat, disclike sacs o Thylakoid membrane encloses a fluid-filled interior space, the  thylakoid lumen o Thylakoid sacs are arranged in stacks called  grana  (looks like a stack on coins) Chlorophyll:  main pigment of photosynthesis, absorbs light primarily in the blue & red  regions of the visible spectrum  (green light is not appreciably absorbed by chlorophyll) o Chlorophyll A- initiates the light-dependent reactions of photosynthesis
Image of page 1

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

View Full Document Right Arrow Icon
o Chlorophyll B -an accessory pigment that also participates in photosynthesis.  Differs from chlorophyll A only in a function group on the porphyrin ring  Chlorophyll-binding proteins facilitate the transfer of energy from one molecule to  another Chloroplasts have other accessory photosynthetic pigments  (carotenoids)  which are  yellow & orange.  Carotenoids  absorb diff. wavelengths of light than chlorophyll Light dependent reactions:  light energy is converted to chemical energy o Begins as chlorophyll captures light energy. The energized electron is transferred  to an acceptor molecule & is replaced by an electron from H2O. H2O is split &  molecular oxygen is released.  o ATP & NADPH  are the products of the  light-dependent reactions Both are needed in the energy-requiring carbon fixation reactions
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern