Cellular respiration is a sequence of three metabolic stages. Stage one is glycolysis and occurs in the cytoplasm. Stages two and three occur in the mitochondria and are respectively called the Krebs cycle and the electron transport chain. Both autotrophs and heterotrophs use these metabolic stages to produce the energy required to grow, reproduce and undertake maintenance, in the form of ATP (Flinders University , 2018). A step in the Krebs cycle can see an enzyme catalysed conversion of succinate to fumarate where an electron is transferred from one complex to another, a redox reaction (Knox, et al., n.d.). Substrate concentration is a variable used to increase the rate of a reaction. It is a limiting factor however, up until a certain point, …show more content…
Additionally, being provided with a singular timer made the act of timing difficult, allowing for inaccurate timing to occur. The temperature of each sample was not kept at a certain temperature, allowing them to sit in room temperature meant that there was the possibility of one sample being slightly warmer of cooler depending on placement allowing more or less cellular respiration to occur, increasing the transmittance percentage. To correct this potential mistake placing all samples in the exact same conditions would improve the reliability of the …show more content…
Flinders University , 2018. Biology Molecular Basis of Life: General Information and Laboratory Manual. Adelaide : College of Science and Engineering.
Hancock, C. N., Wei Liu, W., Alvord, G. & Phang, J. M., 2016. Amino Acids. Co-regulation of mitochondrial respiration by proline dehydrogenase/oxidase and succinate, 48(3), pp. 859-872.
Jones, A. E. & H., G., 1963. Oxidation of succinate and the control of the citric acid cycle in the mitochondria of guinea-pig liver, mammary gland and kidney. Biochemical Journal, 87(3), p. 639–648.
Knox, B., Ladiges, P., Evans, B. & Saint, R., n.d. Biology: An Australian Focus. 5th Edition ed. North Ryde(New South Wales): McGraw Hill Australia PTY LTD.
Qquagliariello, E. & Palmieri, F., 1968. Control of Succinate Oxidation by Succinate‐Uptake by Rat‐Liver Mitochondria. European Journal of Biochemistry, Volume 4(1), pp. 20-27.
Uddin, N., 2012. Enzyme Concentration, Substrate Concentration and Temperature based Formulas for obtaining intermediate values of the rate of enzymatic reaction using Lagrangian polynomial. International Journal of Basic and Applied Sciences, 1(3), pp.
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
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.
In contrast, there are four metabolic stages happened in cellular respiration, which are the glycolysis, the citric acid cycle, and the oxidative phosphorylation. Glycolysis occurs in the cytoplasm, in which catabolism is begun by breaking down glucose into two molecules of pyruvate. Two molecules of ATP are produced too. Some of they either enter the citric acid cycle (Krebs cycle) or the electron transport chain, or go into lactic acid cycle if there is not enough oxygen, which produces lactic acid. The citric acid cycle occurs in the mitochondrial matrix, which completes the breakdown of glucose by oxidizing a derivative of pyruvate into carbon dioxide. The citric acid cycle produced some more ATPs and other molecules called NADPH and FADPH. After this, electrons are passed to the electron transport chain through
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.
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
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
Mitochondrion is considered the energy fuel of the cell. It is the primary site for the ATP production oxidative phosphorylation (OXPHOS) system. The mitochondrial OXPHOS machinery system is mainly composed of five multisubunits complexes (complexes I–V), which are produced by mitochondrial genome. Mitochondrial electron transport chain (ETC) has several essential physiological roles, in which, it is the main source of ATP production in the cell, in addition, its constituent enzyme complexes are a major source of ROS generation. Previous studies tested the effect of A on the mitochondrial bioenergetics function, and have concluded that direct exposure to A leads to significant impairment in the functionality of mitochondrial electron transport
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.
The intracellular redox state is a dynamic system which may modify on many factors. Mitochondria are essential to sustain life and the main intracellular source for fuel generation; moreover engaged in the regulation of many intracellular functions such as redox homeostasis and cell fate. The mitochondrial dynamics have changed and reactive oxygen species (ROS) generation could encourage the induction of oxidative DNA damage, inactivation of phosphatases and transcription factors. Moreover the mitochondrial dysfunction may constantly accompanied and contributed for a broad range of human diseases. Mitochondrial disrepair will result in oxidative stress, which is one of the underlying causal factors for a variety of diseases. High levels of
At first step, the mitochondria were pre incubated in potassium phosphate buffer, succinate and MgCl2. After addition of KCN, antimycin A, the DCPIP and rotenone, the baseline was documented for 3 min. Then, reduction of DCPIP was measured at 600 nm. The activity of complex II was recorded as DCIP mM/min/ mg of mitochondrial protein. Assay of mitochondrial complex IV activity First, sodium hydrosulfite was used to reduce the cytochrome C.
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.
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
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
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