Bio Chem Help! An alternative metabolic pathway (40 points). A new strain of bac
ID: 1039601 • Letter: B
Question
Bio Chem Help!
An alternative metabolic pathway (40 points). A new strain of bacteria has been isolated that can use pyruvate as an energy source and that produces acetate by the pathway shown below (CoA is coenzyme A. You don't need to know its structure to answer this question) Pyruvate Acetyl-CoA Acetyl phosphate Acetate reaction 1 reaction 2 reaction 3 CH3 COA CH3 NAD+ NADH CoA H P COA ADP ATP H20 CO a. Which compound in this pathway is a high energy intermediate? Why should it be considered "high energy?" (1-3 sentences, feel free to draw chemical structures as part of your answer) b. Which step in this pathway is a redox reaction? Is the substrate oxidized or reduced? How do you know? (1-2 sentences) c. This bacterium also has a functional glycolysis pathway. How many moles of ATP could this bacterium produce per mole of glucose that is metabolized by glycolysis+this pathway? Show your work d. Consider only the pathway drawn above. Explain why this pathway could not continue indefinitely in a cell. Propose another pathway, also starting with pyruvate, to run simultaneously so that this pathway can continue indefinitely (1-3 sentences)Explanation / Answer
a. The high energy intermediate is ATP - adenosine tri phosphate. These are the energy currency of cell.When ATP get used in the oxidative phosphorylation and electron transport chain , it produces energy which are necessary for body/cell to work.
b. Reaction 1 - that step in this pathway is a redox reaction.NAD+ is getting reduced to NADH and H+.The substrate that is NAD+ is getting reduced.Because NAD+ is gaining an electron to become NADH - that is how reduction occurs.
c. This reaction is giving 1ATP and 1NADH and glycolysis gives 2ATP and 2NADH.
When NADH goes into electron transport chain it produces 2.5 ATP per NADH.So totally (2+1)=3 NADH will result (3 * 2.5)=7.5 ATP.Total (7.5+1+2)=10.5 ATP will be released.
d. This pathway can not work because the produced acetyl coA is going to enter the TCA cycle with oxaloacetate to produce citrate and run the cycle.
If the condition is anaerobic then pyruvate can go to fermentation pathway to form lactate and in absence of oxygen,the above pathway will run.(As in anaerobic condition TCA cycle won't run).
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