all of the steps of aerobic respiration that we have done so far have been leading up to this the electron transport chain this is the main event the big bonanza the super bowl of cellular respiration why because the vast majority of our atp is made here the electron transport chain is actually a series of proteins and other molecules embedded in the inner membrane of the mitochondrion these molecules transport electrons hence the name let's zoom in on this inner membrane to see the electron transport chain in more detail here's how it works nadh that electron carrier
we've been making all along delivers its electrons to the first protein in the electron transport chain as the electrons move through this protein complex energy is gradually released and this energy is used to pump hydrogen ions or protons across the inner membrane from the matrix into the inter-membrane space at this point it might help to realize that moving electrons is electricity so it should not be surprising that these electrons can provide the energy to drive these microscopic pumps made out of protein they are basically natural electric pumps created way before humans invented them which is
super cool the electrons are then transported by the special red molecule toward their next destination the red molecule also picks up the electrons donated by fadh2 that other electron carrier that we made during the krebs cycle all of these electrons are then passed on to another protein complex at this next protein complex the electron energy is used once again to transport hydrogen ions across the membrane into the intermembrane space notice that we are building up a high concentration of hydrogen ions in the inter membrane space this will be very important soon now the electrons are
transported to a final protein complex where their energy is used once again to pump hydrogen ions into the inter membrane space making the concentration even higher now the electrons need somewhere to go a final destination to complete their journey fortunately you breathe and oxygen comes to the rescue oxygen accepts the electrons as well as hydrogens from the matrix making water this is the reason why you breathe all day every day your cells need oxygen to accept these electrons or the electron transport chain will grind to a halt like an la freeway during rush hour and
if the electron transport chain stops you won't be able to make enough atp to keep you alive and you die so keep breathing that oxygen now you may have noticed that we haven't made atp yet so you might be wondering how that works which brings up the coolest part of this entire process in my opinion remember that high concentration of hydrogen ions we've been building up now it's time to use it to make atp a protein called atp synthase makes a channel that allows hydrogen ions to flow through from high concentration to low concentration you
may remember that molecules tend to move from areas of high concentration to low concentration naturally a process known as diffusion so these hydrogen ions in a manner of speaking want to flow from the high concentration area of the inter membrane space to the low concentration area the matrix but they can only get through atp synthase this facilitated diffusion of hydrogen ions through atp synthase causes atp synthase to spin like a turbine and produce atp such a cool mechanism it's like a microscopic hydroelectric dam generating atp instead of electricity as hydrogen ions passively flow through since
we made many electron carriers throughout respiration the electron transport chain happens over and over again making between 30 to 34 atp molecules for every glucose that entered respiration [Music] if you are doing the respiration activity at bioman biology you should now return to it and complete the tasks related to the electron transport chain the link to the respiration activity is in the description in case you need it if you enjoyed this video please like it subscribe and check out the other free games quizzes and interactive learning experiences at bioman biology
