Cellular Respiration Essay

Succinate dehydrogenase is an enzyme found in the mitochondrial inner membrane. The enzyme catalyzes the reaction of oxidizing its substrate, succinate, into fumarate via the removal of hydrogen ions from succinate. This oxidation is vital in the Krebs cycle.

Understanding the activity of enzymes in different muscle types can aid greatly in obtaining more information about other processes such as metabolism of the tissues (Anderson et al., 2012). There are many different methods in order to achieve this information based in two different major categories but the most convenient method is one called continuous assay. This process includes the use of a spectrophotometer to continuously monitor the assay. This method allows for an easy way to calculate the initial rate of reaction as one can establish time points easily. In the lab performed the continuous method was used in order to determine the measurement of the activity enzyme succinate dehydrogenase (SDH). SDH is most commonly found in mitochondria. It is present in many different muscle tissues including the heart, red, and white tissue. In the following lab the enzyme was tested and measured in these three muscle types in the Oncorhynchus mykiss in order to determine which type contained the highest and the lowest activity. This enzyme is involved in multiple processes such as involved in both the Krebs cycle and the electron transport chain (ETC) (Smith, 2014). Its role in

Eukaryotic cells produce the chemical energy they need through the processes of either oxidative phosphorylation or photophosphorylation. Oxidative phosphorylation is the last step in the process of cellular respiration and accounts for nearly 90% of ATP production during cellular respiration. During stage one of cellular respiration 2 ATP molecules are broken down to provide the energy necessary to start glycolysis. Each glucose molecule is broken down into 2 pyruvate molecules and 4 ATPs are formed. A net gain of two ATPs is realized. In stage two the pyruvate molecules enter into the mitochondrion of the cell. The pyruvate molecules are oxidized into the compound acetyl CoA. In stage three, the acetyl CoA passes into citric acid cycle (Krebs

Two products from the Citric Acid Cycle NADH and FADH2 move from the matrix of the mitochondria and enter into the Electron Transport Chain. As they enter the transport they donate their electrons to Complexes I and II. The Co-Enzyme Q-10 is a vital piece as it retrieves the electrons from Complexes I and II and transports them to Complex III where the it will be used to yield ATP.

Cellular respiration is a metabolic process undergone by all living organisms in order to release adequate amounts of energy essential to life. This series of coupled reaction occurs through breaking down glucose, or other food molecules in the presence of oxygen, releasing the energy contained within the chemical bonds of adenosine triphosphate (ATP). Every step in cellular respiration occurs with the use of enzymes. The simplified equation shown above demonstrates one glucose molecule, in the presence of oxygen produces water, carbon dioxide gas, simultaneously yielding a net of 38 ATP molecules. However, this equation exhibits the three stages of respiration; glycolysis, Krebs cycle, and the electron transport chain.

The first step in Cellular Respiration is Glycolysis. In Glycolysis a six carbon sugar undergoes stages of chemical transformations. In the end it is converted into two molecules of pyruvate, a three carbon organic molecule. In those reactions, ATP is made, and NAD is converted to NADH. The next step in Cellular Respiration is pyruvate oxidation. Each pyruvate from glycolysis goes into the mitochondrial mix ( The innermost compartment of mitochondria. ) It is

The hub of energy metabolism, the mitochondrion, is found in virtually all eukaryotic cells, with the exception being erythrocytes. The mitochondrion generates cellular energy in the form of adenosine triphosphate (ATP), mostly by means of the oxidative phosphorylation (OXPHOS) system that is located in the inner mitochondrial membrane. The respiratory chain (CI-CIV) and ATP synthase (CV) is collectively known as the OXPHOS system, encoded by both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). The number of mitochondria per cell, ranging from hundreds to thousands, is controlled by the energy requirements of specific tissues with the greatest abundance of mitochondria found in metabolic active tissue (Pieczenik and Neustadt, 2007). Mitochondrial disease is caused when there is a defect in any of the numerous mitochondrial pathways, due to spontaneous or inherited mutations. Respiratory chain deficiencies (RCDs) are the largest subgroup of mitochondrial disease and occur when one of the four respiratory chain complexes become impaired. RCDs are considered to be one of the most common

al. 2006). When too much Ubiquinone were produced, and not enough electrons are transferred fast enough to form ubiquinol, the excessive Ubiquinone can oxidize TEO to oxaloacetate (OAA) . OAA then inhibits succinate oxidation. TEO binds to FAD functions to inhibit in the form of Oxaloacetate the flavin protein from taking hydrogen from succinate. In another sense TEO can be present and be inactive unless it was oxidized to OAA. OAA inhibits FAD from regular function (Muller FL, et al. 2007). This exergonic oxidation of malate by ubiquinone contributes to the driving force for loading the enzyme with OAA.

Mitochondria has many key molecules that are present within the organelle. Some of these molecules include oxaloacetate and succinate dehydrogenase, both in which play important roles in cellular respiration. Both of these substrates are essential for the Krebs Cycle, as they both produce ATP within the cycle (Wojtczak, Lech & Wojtczak, A.B. & Ernster, L. 1969). The shape and structure of the molecule oxaloacetate is similar to the components of the molecule succinate dehydrogenase. An active site is part of an enzyme in which a protein or substrate binds to an enzyme (“Active Site.”). Normally,

Succinyl CoA inhibits α- ketoglutarate dehydrogenase and citrate synthase. The enzyme, α- ketoglutarate dehydrogenase, catalyzes the oxidative decarboxylation of α- ketoglutarate (where equilibrium is attained far to the right towards succinyl CoA) and is allosterically inhibited by succinyl CoA. Citrate synthase is also inhibited by succinyl CoA where in the TCA cycle it is converted to oxaloacetate. Therefore, elevated generation of succinyl CoA does not just produce additional oxaloacetate; it also reduces the rate at which it is converted to citrate via inhibition of citrate synthase.

Both cellular respiration and photosynthesis use membrane bound transport chains in their pathways. The reasoning by this is to transfer electrons to generate ATP. In cellular respiration the transport chain carries NADH and FADH2to generate ATP. This is done by electrons being removed from glycolysis which are transported by NADH. Oxygen molecules pick up the electrons, and protons existing in the cellular environment, oxygen molecules form water. The total energy released from glycolysis by oxygen is huge therefore this energy can't be picked up by cells in a short amount of time. Therefore, electron transport chain creates many reactions to slowly release the energy, maximizing the usage of glucose. During these reactions each carrier is

Cellular respiration is the process that takes place in both animals and plants, and it uses to convert food to form ATP. Cellular respiration required several enzymatic steps. During the process of cellular respiration, the cells will break down sugar when the oxygen is present. The first stage of cellular respiration is Glycolysis. It is a metabolic pathway that found in the cytoplasm, it does not require oxygen but the products of glycolysis will break down into steps that require oxygen. Fermentation is an anaerobic metabolism. It is a method to generate ATP when oxygen is not present. The product of fermentation is depending on the enzyme of organism, such as animals produce lactic acid and bacteria produce acetic acid. Fermentation does not produce ATP but it allows Glycolysis to continue. Glycolysis needed 2 molecules of ATP, 1 molecule of glucose to produce 2 molecules of pyruvate, 2 molecules of net ATP and 2 molecules of NADH. The second stage is citric acid cycle, also known as the Krebs Cycle. Krebs Cycle happens in mitochondria matrix. It is a chemical that used by all aerobic organisms to generate energy. Krebs Cycle needed acetyl CoA to produce 6 NADH, 2 FADH, and 2 ATP. Krebs Cycle occurs when oxygen is present. Electron Transport Chain is the last stage of

              This experiment attempts to answer the question of whether an increase in a succinate concentration (a component of the Krebs cycle) will lead to an increased rate of cellular respiration within a cell. We measured the amount of electrons given off by the succinate to fumerate redox reaction by using DPIP. DPIP is an electron acceptor that takes the place of FAD by accepting the electrons and turning from its oxidized blue state to its reduced clear state. We had three tubes with varying concentrations of succinate and measured the transmittance of each over a half hour period to determine whether more succinate led to more DPIP being reduced. The results showed that the tube with no succinate (no

Mitochondrion produces the energy that cell needs by breaking down sugars, fatty acids and amino acids to CO2 and H2O. In this process, which is called cellular respiration, the chemical energy in sugar, fatty acid and amino acid molecules is captured as ATP. Krebs cycle is a part of the cellular respiration that consists of series of reactions. And succinate dehydrogenase is one of the enzymes that is used in this cycle. It basically catalyzes the oxidation of succinate to fumarate. In this reaction, succinate reduces a FAD molecule, which eventually donates its electrons to coenzyme Q. However, Azide prevents FADH2 from giving its electrons to coenzyme Q, rather than an artificial electron acceptor, DCIP takes the electrons. DCIP is a dark blue solution that gets lighter as it gains electrons. As DCIP gets lighter, its absorbance will decrease. So, the rate of the reaction can be relatively observed by looking at the absorbance values of DCIP since the reaction processes, DCIP gains electrons and gets lighter in color. By spectrophotometry we took the absorbance values. Spectrophotometer is used in the process, which sends beams of light to the sample and measures the intensity of the light that passes through the sample. This way we can

Cellular respiration is a vital process that breaks down glucose to create energy. It takes place in aerobic organisms, meaning they require oxygen. The first step in this process is glycolysis where the breakdown of glucose occurs. After this oxidation of the glucose molecule, it becomes a pyruvate, generating 2 ATP and gives away two electrons that convert NADs to NADHs. The pyruvate then enters the mitochondria where it is transformed into acetyl CoA by oxidizing one of the carbons in the pyruvate to co2 (Freeman, 2017). If oxygen is present, this molecule will continue to the citric cycle where it will undergo a series of eight mediated steps where the energy from the acetyl CoA is released to produce FADH and ATP (Freeman, 2017). In the 6th step of the citric acid cycle, succinate is oxidized to fumarate, giving away its electrons which reduces FAD to FADH2. These electrons are then transported to the electron transport chain where ATP, the main goal of cellular respiration, is produced. In this experiment, by substituting with an alternate electron acceptor, we can see and monitor just how quickly the reaction occurs in the presence of more succinate. Because DCPIP turns from blue to colorless as it becomes reduced, by measuring the transmittance of different samples, it will show the amount of DCPIP that has been reduced. If different amounts of succinate are added to the mitochondrial suspension, then the solution containing the most amount of succinate