{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

plant transport - CHAPTER 36 Lithops(Stone Plant-reduces...

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

View Full Document Right Arrow Icon
Plant transport systems To grow and reproduce, plants need resources: O 2 , for respiration water if photosynthetic, CO 2 and access to light in addition to the C, H, and O in water and CO 2 , 14 essential elements if not photosynthetic (i.e., if heterotrophic), a source of reduced carbon compounds Plant transport systems Photosynthetic land plants face major transport problems that get worse as size increases: 1. All of the nutrients needed for photosynthesis -- except CO 2 -- come from the soil (root system) ….. but photosynthesis occurs far away in the leaves (shoot system) 2. Photosynthesis takes place in leaves , but photosynthetic products (sugars) are need in all parts of the plant Bulk flow of materials is essential! (cell-to-cell processes too slow for 2 and 3) Plant transport systems Therefore, plants need to move large quantities of substances over long distances : 1. from soil into roots (water and nutrients) 2. from roots to leaves (water and nutrients) 3. translocation of photosynthetic products By several means, soil nutrients are moved into root tissue: diffusion (if concentration in soil is higher than in roots) -- may be facilitated by transport proteins cation exchange -- addition of H + to soil to displace positively charged minerals (cations) from negatively charged soil particles (secretion of H + ; release of CO 2 ) active transport against a concentration gradient Requires expenditure of ATP proton pump generates transmembrane proton gradient (= a form of energy storage) electrical gradient (negative inside of cells) drives uptake of cations (i.e., K + ) cotransport of substance with protons (i.e., NO 3 - absorbed along with H + ) H + H + H + H + H + H + H + H + H + H + - - - - - - - K + NO 3 -
Image of page 1

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

View Full Document Right Arrow Icon
Root cross-section Root hairs Vascular cells (stele) Once inside the root, how do nutrients reach the vascular system? At least initially, two possible pathways: via the Apoplast (non-living tissue; i.e., cell walls) Root cross-section Once inside the root, how do nutrients reach the vascular system?
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