## Cellular RespirationMr. Hedrick

C 6 H 12 O 6 + 6 O 2 -> 6 C O 2 + 6 H 2 O + ATP Explanation: It is important to know that the equation listed above is a summary equation. The process of cellular respiration involves many different steps (reactions) to break down glucose using oxygen to produce carbon dioxide, water and energy. The 6 carbon atoms present in a glucose molecule make it possible to form 6 carbon dioxide molecules. The 12 hydrogen atoms in the glucose make it possible for form 6 water molecules. To balance the oxygen atoms for the reactant side, you need to count 6 atoms from the glucose. In order to form the 6 molecules of carbon dioxide and 6 molecules of water you will have a total of 18 oxygen atoms on the product side (6 * 2) + (6 * 1) = 18. In order to get 18 oxygen atoms on the reactant side you need an additional 12 oxygen atoms from oxygen O 2 to balance the numbers. The process of cellular respiration will produce 36 ATP molecules in Eukaryotes (plant/animal etc.) for every one glucose molecule. The process will produce 38 ATP molecules for every one glucose in Prokaryotes (bacteria). The reason why eukaryotes produce the smaller amount of ATP is that they need to use energy to move the pyruvate (from glycolysis) needed for the Krebs cycle into the mitochondria. This video gives a quick review of respiration and discusses a lab which tests how temperature can alter the rate of respiration in yeast. The process takes place more quickly in warm conditions because of greater movement of particles
Step 1. A phosphate group is transferred from ATP, to glucose, making glucose-6-phosphate. Glucose-6-phosphate is more reactive than glucose, and the addition of the phosphate also traps glucose inside the cell since glucose with a phosphate can’t readily cross the membrane. Step 2. Glucose-6-phosphate is converted into its isomer, fructose-6-phosphate. Step 3. A phosphate group is transferred from ATP, T, P to fructose-6-phosphate, producing fructose-1,6-bisphosphate. This step is catalyzed by the enzyme phosphofructokinase, which can be regulated to speed up or slow down the glycolysis pathway. Step 4. Fructose-1,6-bisphosphate splits to form two three-carbon sugars: dihydroxyacetone phosphate DHAP, and glyceraldehyde-3-phosphate. They are isomers of each other, but only one—glyceraldehyde-3-phosphate—can directly continue through the next steps of glycolysis. Step 5. DHAP, is converted into glyceraldehyde-3-phosphate. The two molecules exist in equilibrium, but the equilibrium is “pulled” strongly downward, in the scheme of the diagram above, as glyceraldehyde-3-phosphate is used up. Thus, all of the DHAP is eventually converted.

Steps of Krebs Cycle

In order for pyruvate from glycolysis to enter the Kreb's Cycle it must first be converted into acetyl-CoA by the pyruvate dehydrogenase complex which is an oxidative process wherein NADH and CO2 are formed. Another source of acetyl-CoA is beta oxidation of fatty acids. STEP 1: Acetyl-CoA enters teh Kreb Cycle when it is joined to oxaloacetate by citrate synthase to produce citrate. This process requires the input of water. Oxaloacetate is the final metabolite of the Kreb Cycle and it joins again to start the cycle over again, hence the name Kreb's Cycle. This is known as the committed step STEP 2: Citrate is then converted into isocitrate by the enzyme aconitase. This is accomplished by the removal and addition of water to yield an isomer. STEP 3: Isocitrate is converted into alpha-ketogluterate by isocitrate dehydrogenase. The byproducts of which are NADH and CO2. STEP 4: Apha-ketogluterate is then converted into succynl-CoA by alpha-ketogluterate dehydrogenase. NADH and CO2 are once again produced. STEP 5: Succynl-CoA is then converted into succinate by succynl-CoA synthetase which yields one ATP per succynl-CoA. STEP 6: Succinate coverts into fumerate by way of the enzyme succinate dehydrogenase and (FAD) is reduced to (FADH2) which is a prosthetic group of succinate dehydrogenase. Succinate dehydrogenase is a direct part of the ETC. It is also known as electron carrier II STEP 7: Fumerate is then converted to malate by hydration with the use of fumerase. STEP 8: Malate is converted into oxaloacetate by malate dehydrogenase the byproducts of which are NADH.

In general, the bacterial electron transport chains are inducible. According to the medium in which they are growing, the bacteria will synthesize different transmembrane complexes that will produce different transports in their membranes.

Why is important the cellular respiration to life?

Part of the Life Cycle we have on the one hand to Food as one of the most important, being the incorporation of nutrients and proteins to satiate their daily energy needs, the relationship with both the environment and other individuals of the same or another species And finally the Reproduction that allows them to beget new beings of the same species, continuing with a lineage.

It makes our body through the respiratory tract (ie our nose and mouth) and passing to the Respiratory System that is responsible for making a Gas Exchange by expelling the Carbon Dioxide that is harmful to our health, oxygenating our body and Helping to obtain the Energy needed to live.

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