Answer ALL questions please. ALL QUESTIONS 3) Rotenone is a pesticide that preve
ID: 260454 • Letter: A
Question
Answer ALL questions please. ALL QUESTIONS
3) Rotenone is a pesticide that prevents the transfer of electrons from complex I to ubiquinone by blocking the ubiquinone-binding site. How will the inhibition of ubiquinone binding effect on the production of ATP Se will affect overall cell physiology. (I strongly suggest you draw out the complete electron transport chain). 4) Glutamate is a neurotansmitter and glutamine is an amino acid. Both can be created from ?- ketoglutarate, an intermediate of citric acid cycle. Explain the reaction from aketoglutarate to glutamate. How does the use of ?-ketoglutarate affect the citric acid cycle, is energy being transferred in the reactions shown (if so, what type), and how does this affect the overall physiology and energy balance of the cell?Explanation / Answer
3) The flow of electrons from NADPH to Oxygen in an electron transport chain is as follows:
NADPH à complex1 à Q à Comple3 à Cyt C à Complex 4 à O2
Rotenone acts as an inhibitor of transfer of electrons from complex1 to ubiquinone. Ubiquinone is a mobile electron acceptor-donor molecule that connects complex 1 to complex3. The process of reduction of ubiquinone by complex1 results in transfer four protons from matrix side of the inner mitochondrial membrane to intermembrane space. While electron transport through these complexes results in the reduction of Oxygen, the transferred protons to intermembrane space are required for ATP production by ATP synthase complex. Inhibition of ubiquinone binding to complex1 leads to stopping of ETC at the first step and thus, there is no ATP production and oxygen reduction.
Oxygen is used by the complex4 as the final electron acceptor. The reaction is as follows
O2 + 4 e- + 4 H+ à 2 H2O
Reduction of each molecule of oxygen needs four electrons. It needs the electron transport chain to run twice. This oxygen is provided by respiration process. If due to any reason oxygen is not present in the cell. The electron flow across the electron transport chain halts. The proton gradient and ATP production will cease. ATP is necessary for smooth cellular metabolic processes. Thus, oxygen is necessary for cellular respiration and metabolism
4) Transamination reaction converts ?-ketoglutarate to glutamate by transferring an amino group from an amino acid. This reaction is catalyzed by an enzyme called aminotransferases
?-ketoglutarate + amino acid à glutamate + ?-keto acid
?-ketoglutarate is a five-carbon intermediate of the citric acid cycle. It undergoes an oxidative decarboxylation to form a four-carbon compound. TCA cycle is the major energy-yielding process in the cell by producing a reduced form of electron carriers, NADH and FADH2. Thus, conversion of ?-ketoglutarate to glutamate reduces the amount of energy produced by the cell. In other words, the cells need more glucose to fulfill their energy demand.