The tendency for movement in this way is much like water accumulated on one side of a dam, moving through the dam when opened. Citric Acid Production Once pyruvic acid is in the mitochondrial matrix, NAD+ accepts 2 high-energy electrons to form NADH. The cell lacks genes encoding enzymes to minimize the severely damaging effects of dangerous oxygen radicals produced during aerobic respiration, such as hydrogen peroxide (H2O2) or superoxide. 9.2 the process of cellular respiration answer key check unofficial. These notes include Glycolysis, Oxidation of Pyruvate, Krebs Cycle, Oxidative Phosphorylation, and Anaerobic Respiration.
Cellular Respiration Overview. ATP synthase (like a combination of the intake and generator of a hydroelectric dam) is a complex protein that acts as a tiny generator, turning by the force of the H+ diffusing through the enzyme, down their electrochemical gradient from where there are many mutually repelling H+ to where there are fewer H+. Weakness is your body's way of telling you that your energy supplies are low. Electron Transport System. So each molecule of glucose results in two complete "turns" of the Krebs cycle. 9.2 the process of cellular respiration answer key book. In each transfer of an electron through the ETS, the electron loses energy, but with some transfers, the energy is stored as potential energy by using it to pump hydrogen ions (H+) across a membrane. By the end of this section, you will be able to: - Compare and contrast the electron transport system location and function in a prokaryotic cell and a eukaryotic cell. Overall, 2 molecules of ATP are produced. With each rotation, the ATP synthase attaches a phosphate to ADP to produce ATP. Citric Acid Production Pyruvic acid from glycolysis enters the matrix, the innermost compartment of the mitochondrion. Therefore, electrons move from electron carriers with more negative redox potential to those with more positive redox potential.
Cellular respiration is often expressed as a chemical equation: This equation shows that during cellular respiration, one glucose molecule is gradually broken down into carbon dioxide and water. Glucose is broken down into 2 molecules of pyruvic acid, which becomes a reactant in the Krebs cycle. Chapter 9 Student Edition Full | PDF | Cellular Respiration | Glycolysis. The four major classes of electron carriers involved in both eukaryotic and prokaryotic electron transport systems are the cytochromes, flavoproteins, iron-sulfur proteins, and the quinones. Two molecules of CO2 are released.
In reality, the total ATP yield is usually less, ranging from one to 34 ATP molecules, depending on whether the cell is using aerobic respiration or anaerobic respiration; in eukaryotic cells, some energy is expended to transport intermediates from the cytoplasm into the mitochondria, affecting ATP yield. 2 The Process of Cellular Respiration. Compare and contrast the differences between substrate-level and oxidative phosphorylation. Describe the function and location of ATP synthase in a prokaryotic versus eukaryotic cell. Equation for Cellular Respiration. Reward Your Curiosity. I tried my best to visually layout the metabolic pathways of Cellular Respiration for my AP Biology students. Energy Extraction Energy released by the breaking and rearranging of carbon bonds is captured in the forms of ATP, NADH, and FADH2. I made these as a resource for my students to use while studying and do not use them as guided notes during my instruction, however, I did include a fill-in-the-blanks version for any teacher who'd prefer that style. 2 ATP are usually required to bring the pyruvic acid into the matrix. In aerobic respiration, the final electron acceptor (i. e., the one having the most positive redox potential) at the end of the ETS is an oxygen molecule (O2) that becomes reduced to water (H2O) by the final ETS carrier. Overall, the theoretical maximum yield of ATP made during the complete aerobic respiration of glucose is 38 molecules, with four being made by substrate-level phosphorylation and 34 being made by oxidative phosphorylation (Figure 8. Lipids and proteins can be broken down into molecules that enter the Krebs cycle or glycolysis at one of several places.
If you are like most people, you feel sluggish, a little dizzy, and weak. At the end of the electron transport chain, the electrons combine with H+ ions and oxygen to form water. These electron transfers take place on the inner part of the cell membrane of prokaryotic cells or in specialized protein complexes in the inner membrane of the mitochondria of eukaryotic cells. What are the functions of the proton motive force? Directions: Watch the video Energy Consumption: An Overview for a look at the different cellular processes responsible for generating and consuming energy. However, it usually results in the production of 36 ATP molecules. Glycolysis does not require oxygen, so it can quickly supply energy to cells when oxygen is unavailable. Thus, the 10 NADH molecules made per glucose during glycolysis, the transition reaction, and the Krebs cycle carry enough energy to make 30 ATP molecules, whereas the two FADH2 molecules made per glucose during these processes provide enough energy to make four ATP molecules. Cellular Respiration: The Citric Acid Cycle (or Krebs Cycle). One possible alternative to aerobic respiration is anaerobic respiration, using an inorganic molecule other than oxygen as a final electron acceptor. Cellular Respiration Summary. Microbes using anaerobic respiration commonly have an intact Krebs cycle, so these organisms can access the energy of the NADH and FADH2 molecules formed.
All in all, the breakdown of a single molecule of glucose yields 36 molecules of ATP. Learning Objectives. Also, 2 molecules of NADH are made. This electrochemical gradient formed by the accumulation of H+ (also known as a proton) on one side of the membrane compared with the other is referred to as the proton motive force (PMF). ATP Production H+ ions pass back across the mitochondrial membrane through the ATP synthase, causing the ATP synthase molecule to spin.