{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture_notes_03_(ta)

lecture_notes_03_(ta) - Lecture 3 Membrane Transport...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 3: Membrane Transport Reading: chapter 3, section: membrane transport, pgs 57-70 (pgs 53-64, if using 3 rd edition) (TA NOTES IN RED . P LEASE NOTE THAT I AM USING AN OLD VERSION OF THE LECTURE NOTES . FIGURE AND PAGE NUMBERS REFER TO THE FIFTH E DITION OF OUR TEXT …) Intercellular Communication Gap junctions ( CYTOPLASM IS CONTIGUOUS ) Communicating junctions that permit the passage of small molecules ( AND IONS ) Direct signaling ( CELLS BIND TOGETHER , BUT CYTOPLASM IS NOT CONTIGUOUS ) Extracellular protein-protein interactions Extracellular chemical messengers (Figure 3-7) paracrine ( LOCAL , NO ELECTRICAL SIGNAL INVOLVED ) hormone ( GLOBAL , THROUGH BLOODSTREAM , NO ELECTRICAL SIGNAL INVOLVED ) neurotransmitter ( LOCAL , ELECTRICAL SIGNAL INVOLVED ) neurohormone ( GLOBAL , ELECTRICAL SIGNAL INVOLVED ) How are extracellular chemicals secreted by one cell detected by another? 1. G protein coupled receptors, coupled to 2nd messengers pathways e.g. cAMP, IP3 pathways These pathways ultimately bring about a cellular response by altering the structure and function of proteins. ( DO NOT HAVE BUILT - IN ION CHANNEL PORE ) 2.  Activation of ion channels Ion channels are membrane proteins that permit small soluble ions such as Na, K, Ca and Cl to pass across the plasma membrane. There are two major types: leak channels, which are always open, and gated channels, which open and close in response to various stimuli. Different types of gated channels are gated by changes in membrane voltage, mechanical deformation,or binding of chemical messengers. For the latter category, there are two types: Ionotropic signaling Activation of ion channels by direct binding of extracellular chemical messenger ( RECEPTOR + PORE PROTEIN COMPLEX ) Metabotropic signaling Activation of ion channel via 2 nd messenger pathway.
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
Image of page 2
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