The Electron Transport Chain (ETC)

An electron transport chain (ETC) couples a reaction between an electron donor (such as NADH) and an electron acceptor (such as O2) to the transfer of H+ ions across a membrane, through a set of mediating biochemical reactions. These H+ ions are used to produce adenosine triphosphate (ATP), the main energy intermediate in living organisms, as they move back across the membrane. Electron transport chains are used for extracting energy from sunlight (photosynthesis) and from redox reactions such as the oxidation of sugars (respiration). In chloroplasts, light drives the conversion of water to oxygen and NADP+ to NADPH and a transfer of H+ ions. NADPH is used as an electron donor for carbon fixation. In mitochondria, it is the conversion of oxygen to water, NADH to NAD+ and succinate to fumarate that drives the transfer of H+ ions. While some bacteria have electron transport chains similar to those in chloroplasts or mitochondria, other bacteria use different electron donors and acceptors. Both the respiratory and photosynthetic electron transport chains are major sites of premature electron leakage to oxygen, thus being major sites of superoxide production and drivers of oxidative stress. More info: Spongelab Biology:
Video Rating: 4 / 5

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Comments ( 7 )
  1. The Electron Transport Chain (ETC) « Hourly Book
    November 6, 2012 at 1:10 pm

    […] Biology education Like this:LikeBe the first to like this. Categories: Uncategorized Comments (0) Trackbacks (0) Leave a comment Trackback […]

  2. Shauno19882010baby
    November 6, 2012 at 1:42 pm

    NadH and FADH2? Yep, Ive worked out they produce atp at some point but where they come from and how they are produced beats me.

  3. TheDavidferal
    November 6, 2012 at 1:45 pm

    must be a new pedagogic trick to wake interest Muahhhhhhh

  4. lonly4uonly
    November 6, 2012 at 2:14 pm

    could you please upload something related to atp and adp translocase and their physiological role and regulation/ modulation

  5. jeremyspongelab
    November 6, 2012 at 2:52 pm

    The complex not illustrated in the video is complex II (succinate dehydrogenase). Complex 2 is a bit of an odd-ball in the electron transport chain (ETC) and it’s the only enzyme shared among both the Citric Acid Cycle and the ETC. It’s responsible for bring the FADH into the system, bypassing complex 1 – going right into complex 3 (the reason why FADH generated less net ATP as compared to NADH). Complex 2 was not but you can see FADH coming in, appropriate ratios to NADH, to complex 3.

  6. solacehaven
    November 6, 2012 at 3:45 pm

    aren’t there 4 complex?

  7. DmonHnter599
    November 6, 2012 at 4:29 pm

    She sounds so excited about it.

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