Can someone explain aerobic respiration and ATP formation in better terms?
Jan.25, 2010 in
Aerobic Respiration
I’ve gone over it a few times, and still need just a short, easy to remember run-down explanation if possible.
Question:
Can someone explain aerobic respiration and ATP formation in better terms?
January 25th, 2010 at 1:31 am
Since I’m not certain of the amount of detail you need, let’s start with this.
During the breakdown of glucose by glycolysis and then by the citric acid cycle, the glucose molecules are oxidized to CO2. Those oxidation reactions form NADH and FADH2. (The oxidation of other nutrient molecules ultimately produces the same reduced electron carriers.) NADH and FADH2 are both oxidized by the electron transport system. This system of proteins in the inner mitochondrial membrane remove electrons from NADH and FADH2 and through a series of steps transfer those electrons to oxygen, forming water. As the electrons are passed from one protein complex to the next, protons are actively transported out of the matrix of the mitochondrion, setting up a proton electrochemical gradient across the inner mitochondrial membrane. As protons flow back into the matrix through ATP synthase, the energy they release drives the formation of ATP from ADP and phosphate ions.
Don’t know if that’ll help, but it’s my best initial shot…
January 25th, 2010 at 2:02 am
Aerobic respiration has four stages
Glycolysis – A six-carbon glucose molecule is converted to two, 3-carbon molecules of pyruvate. This process occurs in the cytoplasm. In order to initiate the process, 2 molecules of ATP are consumed. Four molecules of ATP and 2 molecules of NADH are produced;
Formation of acetyl coenzyme A – Each pyruvate molecules is oxidized to carbon dioxide and a 2-carbon acetyl group. The carbon dioxide is released as a waste product, and the 2-carbon acetyl group is bound to coenzyme A and brought into the mitochondrion;
The citric acid cycle – Each of the 2-carbon acetyl groups produced from the original glucose molecule is bonded to a pre-existing molecule of oxaloacetate to form citrate (i.e. citric acid). These two citric acid molecules are gradually oxidized, and the hydrogen ions are bound to NAD to form NADH and to FAD to form FADH2. Oxaloacetate is produced when the last carbon atom is released in the form of carbon dioxide;
Electron transport chain and chemiosmosis – The electrons removed from the molecules in glycolysis and citric acid follow a series of cytochromes on the mitochondrial membrane, while the hydrogen ions (protons) are pumped across the inner membrane of the mitochondrion. These protons flow through ATP synthase enzyme molecules, and thereby release energy which drives the formation of ATP molecules.
January 25th, 2010 at 2:16 am
Aerobic respiration:
Aerobic respiration is the release of energy from glucose or another organic substrate in the presence of Oxygen. Strictly speaking aerobic means in air, but it is the Oxygen in the air which is necessary for aerobic respiration. Anaerobic respiration is in the absence of air.
As for the ATP formation I myself am having trouble finding layman terms for that or even a solid definition. As it can happen in different variables, need to know what its for I suppose. Good luck though!