Cellular Respiration: Glycolysis, Krebs Cycle, Electron Transport Chain

hi guys in today's video we'll be talking a little bit about cellular respiration as you guys may know cellular respiration is the process in which we go from glucose into ATP there's other reactants and other products and I'll write it on the board before we talk about it a little bit in addition to talking about cellular respiration and the three parts we'll look into the reactants the products other products as well as the number of ATP that we make in an entire cycle of cellular respiration we start with c6 h-12 o-6 it looks like a super long name but essentially all that is is glucose glucose plus oxygen will result in the production of carbon dioxide water and energy energy in the form of ATP I lists up here the six things I will take a look at we'll look at the type of step of cellular respiration one of three we'll look at where takes place within a cell we'll take a little look at the reactants so what goes in the input and we'll also examine the main products as well as byproducts that are produced during this reaction at the very end we'll take a look at the number of ATP and then take the entire summary for how much ATP we've made in total the first step of cellular respiration is glycolysis the place that glycolysis takes place is within the cytoplasm so I'll have an image of a cell and I'll show you guys exactly where glycolysis occurs so here's my cell I'll draw in a nucleus as well as a nucleolus you can also imagine the endoplasmic reticulum and I'll put in a very large mitochondria so this is very important step number one glycolysis occurs in the cytoplasm great so what goes into glycolysis as you can probably figure out from the name glycolysis literally means cleaving or cutting a simple sugar so the sugar that we are kind in this case is glucose glycolysis lysis meaning splitting so we're splitting up a sugar or more specifically Lucas this process is anaerobic which means we do not require the presence of oxygen the major product of glycolysis is a molecule known as pyruvate while glucose is a molecule with six carbons pyruvate only has three carbons which means that a six carbon glucose can be broken down into two 3-carbon pyruvate molecules and during this reaction in which glucose becomes two molecules of pyruvate there are no really major brad products that we produce however we will yield some ATP unfortunately glycolysis doesn't result in a lot of ATP which means we cannot perform glycolysis for too long or rely on it too much for our source of energy and the reason for that is because what call us this only produces two molecules of ATP two molecules of ATP is really not a lot which is why we need to perform various other steps during cellular respiration to give us the energy that we need to carry out our daily lives the second step of cellular respiration no longer occurs in the cytoplasm instead the two molecules of pyruvate that we just produced will move on somewhere else so will happen to the two molecules of pyruvate they actually move from the cytoplasm directly into the mitochondria after a series of modifications as soon as pyruvate moves into the mitochondria we can begin the second step which is known as citric acid cycle you may also see the citric acid cycle written as TCA which stands for a tricarboxylic acid cycle or the Krebs cycle again the Krebs cycle or the citric acid cycle does not take place in the cytoplasm anymore we've moved on from the cytoplasm into the powerhouse of the cell which you may remember is the mitochondria the two molecules of pyruvate that we produced during glycolysis will then move on to be the reactants of our next reaction as a result of the Krebs cycle pyruvate will become a product in this case pyruvate will turn into some high energy electron carriers you may see these high-energy electron carriers written as nadh and fadh2 you might also see them written as high energy electrons or electron carriers I'll call them here high energy electron carriers and make a note that you might also see the nice nadh or fadh2 again in the mitochondria pyruvate turns into these high energy electrons the byproduct of this reaction is carbon dioxide remember when humans are breathing we're eating sugar and breathing in oxygen we always exhale carbon dioxide as a waste product if anyone ever asks you where that carbon dioxide comes from you'll know that the step in which this occurs is the Krebs cycle or the citric acid cycle carbon dioxide gas is a byproduct of this reaction where pyruvate becomes these electron carriers during the Krebs cycle the number of HTTP that we produce is still not a lot it's still not a lot - it's not enough to power the reactions of daily life unfortunately the Krebs cycle is only able to provide us with two molecules of 18 the third and final step of cellular respiration continues in the mitochondria we're still in the mitochondria and we are going to use this time the high energy electron carriers to produce our product if in the mitochondria we have these high energy electron carriers bringing electrons down a chain and the only logical name for the system or the step instead of the respiration is the electron transport chain because what are we doing we are removing these electrons from very low electronegativity down from carrier to carrier until our very last carrier is extremely electronegative that's why it's chain the main product of this reaction unlike being an intermediate is actually ATP so all of this was done with the goal of the intention of producing a ton of ATP through the electron transport chain as for the byproducts I pointed out earlier that in the electron transport chain we're pulling the electrons to carriers with increasing electronegativity you might remember from chemistry class that the most electronegative atom that we look at in this reaction is oxygen oxygen is the final electron acceptor when it accepts the electrons it also accepts two protons or two hydrogen ions when this happens you have an oxygen and two hydrogen's you produce water the water is the same water that we exhale in the form of water vapor with every single breath so whenever we perform cellular respiration we are exhaling carbon dioxide and water which come from the krebs cycle and the e.t.c most importantly the number of ATP in this final step clearly outweighs the ATP that we produced before during the electron transport chain we produce an amazing 28 molecules of ATP some sources that you see may say that you are producing 30 or 32 ATP molecules and the answer is it really does depend it depends on whether you are using nadh or fadh2 it depends on the high energy electron carriers that are involved in the reaction for the most part however you will see 28 ATP ultimately we have two ATP produced in glycolysis from the cytoplasm there's two ATP produced in the Krebs cycle which happened in the mitochondria and finally 28 or 30 ATP produced as well in the mitochondria through the electron transport chain in the end we have 2 plus 2 plus 28 which gives us a total of 32 ATP let's do a full recap of cellular respiration first of all there's three steps we have glycolysis the Krebs cycle or the citric acid cycle followed by step 3 which is the electron transport chain first we started in the cytoplasm for glycolysis where we went from glucose into two molecules of pyruvate the pyruvate turned into high energy electron carriers and this step happened in the mitochondria there was some ATP produced during both reactions finally these high-energy electron carriers performed a very important step in which 28 molecules of ATP were produced and as well during this reaction we have a by-product which is water we moved from the cytoplasm into the mitochondria and we began with flucos and we ended with a ton of ATP that's the whole goal of Stella their respiration is to go from our glucose into energy and that's exactly how we did it so we had one molecule of glucose and they gave us in the end 32 molecules of ATP or energy I hope this video was very helpful for you guys if you have any questions feel free to come see me in my office or we can also communicate through email thanks for watching and if you have any other video ideas don't hesitate let me know I'm love making videos thanks guys

Channel: Anatomy Academy

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Keywords: anatomy, physiology, biology, chemistry, biochemistry, tutor, learning centre, learning circle, Morningside, Centennial, Cindy, Cindy Wei, tutoring, ANAT113, ANAT106, ANAT100, practical nursing, nursing, crash course, cellular respiration, kreb cycle, glycolysis, electron transport chain, cells

Id: XIwJcl-hpKs

Length: 11min 0sec (660 seconds)

Published: Sat Oct 21 2017