Glycolysis Essay

1. Glycolysis is an essential anaerobic pathway for ATP production in the body. There are various steps and processes that occur and lead to the production of various products and most importantly ATP. Let’s dive right into it and get started on the process of glycolysis. Glycolysis occurs in the cytosol of the cell and can be divided into three different phases, which include sugar activation, sugar cleavage, and lastly sugar oxidation and ATP formation. The first steps in glycolysis require ATP to get started, this can be thought of as the investment phase of glycolysis. Hexokinase strips a phosphate group from ATP and attaches it to the glucose creating glucose-6-phosphate. Phosphoglucoisomerase re arranges the existing molecule to from

Pyruvic acid, a charged molecule, enters the mitochondria with the help of a transport protein. The transitional phase then converts the pyruvic acid into the useful acetyl CoA. These steps are important to understand to fully grasp the Krebs cycle. Decarboxylation removes one carbon from the pyruvic acid and carbon dioxide gas is released. The CO2 is released through the lungs and this is the first time this happens during cellular respiration. Oxidation is the next step and this occurs when the remaining 2 carbon fragment are oxidized to form acetic acid through the removal of hydrogen atoms. The hydrogen’s are picked up by NAD+. Acetic acid then is combined with coenzyme A to form acetyl CoA. The acetyl CoA is then joined with oxaloacetic acid to produce a 6-carbon citric acid. The Krebs cycle can also be referred to as the citric acid cycle. Once the cycle starts moving through each successive step, atoms of the citric acid are rearranged to produce intermediate molecules called keto acids. Through this cycle each of the two pyruvic acids each create 1 ATP 3 NADH and 1 FADH2. After this process the real ATP maker in the three-step process of cellular respiration can occur, the electron transport

The ETC carries out catabolic reactions that occur in the inner mitochondrial membrane. In the ETC hydrogen’s are removed during oxidation and are combined with the O2 to form water. The energy that is released from this reaction is utilized to attach phosphate groups to ADP, which forms the desired product of ATP. This process is defined as oxidative phosphorylation. Cofactors along the membrane of the mitochondria are the primary tools used for the ETC; these can be referred to as different complexes I-V. The reduced coenzymes NADH and FADH2 deliver the electrons to the first and second complex. These electrons are then transferred along the membrane from complex to complex each of which is reduced then oxidized. This pumps H+ into the intermembrane space, which creates an electrochemical gradient. The coenzyme ubiquinone helps to shuttle electrons between the larger complexes. At complex IV the electron pairs combine with protons and the formation of water occurs. Lastly at the ATP synthase complex the energy of the gradient is utilized to synthesize ATP. As the H+ flows between the membrane through the ATP synthase the rotator spins causing the phosphate to attach to ADP causing the formation of