Transcript of Respiration
Glycolysis Takes place in the cytoplasm of the cell Two ATP, are oxidized and drop off their phosphate group onto the glucose molecule, which turns into Fructose 6-Phosphate The Fructose 6-phosphate then splits into two glyceraldehyde 3-phosphates (GALP) These GALP molecules are then oxidized when an NAD+ molecule comes and becomes NAD+H+, for each of the GALPs. At the same time, 2 ADP, for each GALP come and pick up a phosphate group each, and form 2 ATPs. The end product is called pyruvate. At the end, there are 2 ATPs and 2 NAD+H+ molecules as net gains from this process. The NAD+H+ molecules play a significant role in the ETC later on. Respiration Krebs Cycle The two pyruvats now enter a process called the krebs cycle which occurs in the Mitochondria of the cells. Link Reaction In the link reaction, the pyruvate from glycolysis transforms into Acetyl CoA, which is a two carbon molecule. During the link reaction, two NAD+ molecules oxidize the two pyruvates. They turn into NAD+H+. At the same time, one carbon atom is lost and coenzyme A bonds with the two carbon moleculte to form acetyl CoA. When the acetyl CoA enters the krebs cycle, it is bonded with a 4 carbon compound, called oxaloacetate, which then forms Citrate. Through out the Krebs Cycle, as this citrate is broken down into oxaloacetate again, it will produce 2 ATPs, one, from each of the acetyl CoAs brought into the Krebs Cycle. After 1 Carbon has left the cycle, one NAD+ comes and Oxidizes the molecule, which is now called alpha-ketoglutarate which is a 5 compund molecule. Once again, after another Carbon leaves the cycle, a NAD+ comes and oxidizes the molecule, becoming NAD+H+, but also energy, enough to synthesize one ADP with a Phosphate group to form ATP will be let out, forming one ATP. The 4 carbon molecule is now called a succinate. Theen an FAD molecules comes and oxidizes the succinate, which makes it inta Malate. When it becomes a malate, once again 2 NAD+ oxidizes the malate and turn into NAD+H+s. After this process, the 4 carbon molecule is onve again called Oxaloacetate, and it is ready to bond with a new set of acetyl-CoA. Quick Check: The Krebs Cycle takes place in the mitochondria of the cells,Full transcript
One ATP is generated by one reveolution of the krebs cycle. Electron Transport Chain (ETC) The Electron Transport Chain occurs in the inner membranes (Cristae) of the mitochondria. At first, the NAD+H+ produced in the Krebs Cycle is oxidized by the NAD Dehydrogenase, and energy enough to send one hydrogen atom into the intermembrance space is created. Now, two electrons are in the NAD Dehydrogenase. These electrons are then passed onto the cytochrome b-c complex. At the same time, one hydrogen atom is pumped into the intermembrane space. As the electrons are passed from carrier to carrier, a small amount of energy is released which helps the Hydrogen ion enter the intermembrane space. As there is a concentration gradient between inside inner membrane of the mitochondria and the intermembrane space, this is used to produce ATP. ATP synthase, spins and synthesizes ATP when a H+ ion is let through it. Finally, the H+ ion that was used to synthesize the ATP, is then accepted to a molecule with two oxygen atmon. They form H2O, which is let out by methods such as exhalation. The Cycle Repeats Itself.