The Krebs or Citric Acid Cycle is an important means by which energy is produced in the body. If the body is not allowed to complete this cycle, there is a tremendous loss of ATP, the primary source of energy for cells. After the cycle, the body has plenty of energy to meet its needs. Without this cycle, glucose is not used efficiently. It occurs in the mitochondria, the “powerhouses” or energy factories of the cell. An important aspect of the Krebs cycle is the electron transport chain that occurs as part of it (Tate, n.d.).
In the cycle, glucose is broken down into pyruvate. Pyruvate is transformed into acetyl coA. As carbon dioxide is released to from a carbon molecule, NAD is transformed into NADH. After this, a second oxidation and decarboxylation ensues. In this step, another NADH and CO2 are formed. One molecule of ATP is formed. This also results in a 4-carbon molecule which is then further oxidized. During the Krebs Cycle, one glucose molecule is broken down into two pyruvate molecules, both of which then enter the cycle. Both pyruvate molecules must go through one cycle each to create ATP at the end of the cycle.
Towards the end of the cycle, the electron transport chain is used to create ATP, a fuel source for the body. Two molecules, NADH and FADH2 were formed as a result of breaking down sugar and the cycle. Electrons with tremendous amounts of energy were needed to move the cycle along. As these electrons jump through the cycle, they lose a little bit of energy with each step. This energy is used to create ATP. It allows the adenosine molecule with two phosphates to join with a third phosphate. This is what ATP is. ATP is a molecule that possesses tremendous amounts of energy. This energy provides the power for the entire body. If this cycle and transport chain cannot happen, then the body will not have enough power to survive (The Guide, n.d.).
- Tate, SS. (n.d.). The Krebs cycle. Retrieved February 26, 2014, from: https://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_the_krebs_cycle_works__quiz_1_.html
- The Guide. (n.d.). The Krebs cycle. Retrieved February 26, 2014, from: http://library.thinkquest.org/27819/ch4_6.shtml