How fermentation and respiration similar?

Answer 1

respiration and fermentation both extract energy from food

Answer 2

Cellular Respiration

1. Glycolysis - occurs in the cytosol begins the degradation process by breaking glucose into two molecules of pyruvate. Glucose is a six carbon sugar, and it becomes split up into two three carbon sugars. Glycolysis has two phases, energy investment and energy payoff. In order to begin glycolysis, the cell must spend two ATP molecules. Directly from glycolysis, 4 ATP are made. Once the cell is paid back for its loss of two ATP's, the net gain of glycolysis can be said to be 2 ATP. Along with making ATP, the cell also makes 2 NADH
2. Citric Acid Cycle - takes place in the mitochondrial matric of eukaryotic cells, or in the cytosol of prokaryotes. This completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide. The carbon dioxide that is produced by respiration represents fragments of oxidized organic molecules. The first thing that must be done to the pyruvate produced during glycolysis is that it must become Acetyl CoA, or Acetyl coenzyme A. Pyruvate enters the mitochondria by the way of transport protein. Once the pyruvate enters into the mitochondria, a couple different enzymes work on the molecule so that it become acetyl CoA. While it is becoming acetyl CoA, a CO2 molecule and a NADH molecule are given off. Acetyl CoA is very reactive and unstable which means that it will have a highly exergonic reaction. Acetyl CoA enters the citric acid cycle with the Acetyl part of the molecule is separated from the coenzyme A part. The acetyl group combines with oxaloacetate to make a 6 carbon molecule called citrate. When the 6 carbon molecule (citrate) loses a carbon, giving off CO2, the cycle also gives off a NADH molecule and it becomes a 5 carbon molecule. When the 5 carbon molecule gives off a carbon, that becomes CO2, another NADH molecule is given off and the molecule is now a 4 carbon molecule. In order for this four carbon molecule to become oxaloacetate that is used at the beginning of the citric acid cycle, the molecule must be rearranged. This gives off an ATP molecule, an FADH2 and a NADH. The rearranging takes 4 steps to complete. And once the molecule has been rearranged to oxaloacetate, the cycle starts again. The output of the citric acid cycle is 2 carbon dioxide, 3 NADH, 1 ATP, and 2 FADH2
3. Oxidative Phosphorylation - the electron transport chain accepts electrons from the breakdown products of the first two stages (FADH2 and NADH) and passes these electrons from one molecule to another. The energy released at each step of the chain is used to pump hydrogens across the inter-cell membrane of the mitochondria. This is so that between the two membranes will become concentrated with hydrogen ions. This way, when the hydrogen ions naturally diffuse down their energy gradient, they will have to go through the ATP synthase molecule which will create ATP molecules for the cell. For every 3 hydrogen ions that diffuse down the concentration gradient through ATP synthase 1 ATP molecule is made.

Electron Transport Chain

NADH gives two electrons to the first protein in the electron transport chain. NADH then become NAD+. NADH is able to give its two electrons to the beginning of the chain. The actual electron transport chain is a collection of molecules, mostly proteins that are embedded in the inter cell membrane of the mitochondria. Since the inner membrane of the mitochondria is folded so much (maximizes surface area) there are thousands of electron transport chains. Along with the proteins there are prosthetic groups (non protein components essential for catalytic functions of certain enzymes). As the electrons travel down the chain, they experience a drop in free energy. As the electron carriers donate and accept electrons, the carriers alternate between reduced and oxidized states. When the molecule accepts electrons from its uphill neighbor the molecule becomes reduced. The molecules lower on the chain have higher electronegativities. When the molecule passes the electron to its downhill neighbor, the molecule becomes oxidized. Most of the electron carriers are cytochromes (they have a heme group that has an ion which donates and accepts electrons). At the very end of the chain, the electron is given to an oxygen molecule which combines with two hydrogens to form water. FADH2 can also donate two electrons like NADH. When FADH2 donates the electrons, the electrons enter at a lower stage than NADH's electrons (NADH's electrons enter at complex 1 while FADH2's electrons enter at complex 2). Since FADH2's electrons enter at complex 2, they provide one third less energy then NADH. The electron transport chain makes no energy directly. Instead, as the electrons fall down the electron transport chain, their energy given off is used to pump hydrogen ions out of the inner cell membrane to the other against the hydrogen's concentration gradient (active transport). This way, the hydrogen ions will power ATP synthase to make the actual ATP. The electron transport chain breaks a large free-energy drop into a series of smaller steps so that more manageable amounts of energy are released.

Role of Oxygen in Cellular Respiration

Oxygen is necessary for cellular respiration because is allows pyruvate to become acetyl CoA. Oxygen is also needed because it is the final electron receptor and final destination of the electrons as they go down the electron transport chain. The oxygen basically drags the electrons down the electron transport chain. The citric acid cycle uses oxygen, and so does oxidative phosphorylation. Therefore, only glycolysis could occur without the presence of oxygen.

Fermentation and Anaerobic Respiration

1. Instead of oxygen being the final electron acceptor, the final electron acceptor is an organic molecule such as pyruvate (for lactic acid fermentation) or acetaldehyde (for alcohol fermentation)
2. Without oxygen, the energy that is stored in pyruvate is unavailable to the cell, therefore, cellular respiration with oxygen yields up to 19 times as much ATP per glucose molecule as fermentation.

1. Anaerobic Respiration - organisms have an electron transport chain, but do not use oxygen as a final electron acceptor
   1. Fermentation is an expansion of glycolysis that allows continuous generation of ATP by the substrate level phosphorylation of glycolysis. There must be a sufficient supply of NAD+ to accept electrons during the oxidation step of glycolysis
   1. NAD+ is regenerated by transferring electrons for NADH to pyruvate or derivatives of pyruvate. The NAD+ can then be reused to oxidize sugar by glycolysis, which nets two molecules of ATP by substrate level phosphorylation.
2. Fermentation - a way to harvest chemical energy without using oxygen or electron transport chain.

Answer 3

Both fermentation and cellular respiration release energy from glucose and other food molecules. They are different because respiration uses energy from glucose.

Answer 4

Fermentation is a part of cellular respiration. It is part of anaerobic cellular respiration. It is used to keep glycolysis from stopping.