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The key reaction that led to Boyer’s proposed loose-tight-open mechanism for the reaction catalyzed by ATP synthase is shown below. The experiment was done in the presence of 18O labeled water with the free purified enzyme. It was the results of this experiment that led him to propose this unique mechanism of action for the synthesis of ATP by ATP synthase in the late 1950s. Briefly explain what aspect of this experiment implied that the ATP is formed by ATP synthase all by itself outside of the cell. (2 pts.) ADP + Pi + H2O18    

Name a parallel reaction that we have encountered for reaction 3. Type in the letter that corresponds to the correct answer. [Q17]

For reaction 2, name a reaction we have studied that is parallel to this reaction. Type in the letter that corresponds to the correct answer. [Q16]

Questions 16-20 Identify the cofactor or parallel reaction for each question. Some answer options may be used more than once, and some answer options will not be used. Some questions have more than one acceptable answer that will receive credit.  Use the image below for questions 16-20. Answer Options for 16-19 Aldolase Aconitase Alpha ketoglutarate dehydrogenase complex Enolase Fumarase Hexokinase Pyruvate dehydrogenase complex Pyruvate kinase Succinyl CoA synthetase Succinate dehydrogenase     Image Description A stepwise biochemical pathway showing the conversion of a substrate into Acetyl CoA through six steps. The pathway begins with leucine. In step 1, leucine is deaminated, with the amine being replaced by a ketone. In step 2, the carboxylic acid is removed and replaced by SCoA. In step 3, a single bond between a CH and a CH2 is replaced by a double bond, both carbons losing one hydrogen in the process. In step 4, one of the methylene groups on the terminal end of the leucine’s R chain has a carboxylic acid attached to it. In step 5, the carbon-carbon double bond created in step 3 is removed, with the CH being converted back into CH2 and the C getting an alcohol attached to it. In step 6, acetyl CoA is removed from the structure. 

The following is from a brief description of some research on hair growth: “New drugs promoting hair growth may soon be on the market, as researchers from UCLA have developed a new way to activate the stem cells in the hair follicle to make hair grow. Hair follicle stem cells are long-lived cells in the hair follicle that are present in the skin and produce hair throughout a person’s lifetime. The stem cells are normally inactive, but can quickly activate during a new hair cycle when growth occurs.”  Continuing, “….researchers from the University of Utah increased lactate production genetically in the mice to accelerate hair follicle stem cell activation and ultimately increase the hair cycle. Before this, no one knew that increasing or decreasing the lactate would have an effect on hair follicle stem cells,” William Lowry, a professor of molecular, cell and developmental biology at UCLA, said in a statement. “Once we saw how altering lactate production in the mice influenced hair growth, it led us to look for potential drugs that could be applied to the skin and have the same effect. (Walter, K. (August 15, 2017).  Researchers Discover New Key to Hair Growth. Retrieved from R&D World.) Upload an image of your answer to this question. One of the potential hair-growth stimulating drugs mentioned in the article is UK5099, which blocks pyruvate from entering the mitochondria. Briefly explain why blocking the entry of pyruvate into the mitochondrial matrix would result in lactate production and show the reaction(s) that would be expected to form lactate from pyruvate. (3 pts.)   Lactate is also formed in muscle cells under anaerobic conditions and subsequently shipped via the blood to the liver for re-incorporation into glucose via gluconeogenesis. Briefly explain why, under these conditions, lactate is required to keep ATP production via glycolysis active.  (1 pt.)   Under anaerobic conditions, many microorganisms convert pyruvate to ethanol. In this pathway, pyruvate is converted to acetaldehyde, which, in turn, is converted to ethanol. Show the reaction that converts acetaldehyde to ethanol. Show the structures of the substrate and the product, and include any required cofactors or co-reactants, as well as the name of the enzyme that catalyzes the reaction. (2 pts.)  

Name a parallel reaction that we have encountered for reaction 5. [Q18]

Name a parallel reaction that we have encountered for reaction 3. [Q17]

The average cost (COST) of heating a home is a function of outside Temperature (TEMP), thickness of Insulation (INSUL) and Age of furnace (AGE). Data is collected on these variables and a regression analysis is done on the data. An incomplete MS Excel output is shown below.   Regression Statistics         Multiple R           R Square           Adjusted R Square           Standard Error           Observations                        ANOVA             df SS MS F Signifcance F Regression   171220       Residual           Total 19 212916                     Coefficients Standard Error t Stat P-Value Lower 95% Intercept 427 59.6 7.17     TEMPT (X1)   0.7723 -5.93     INSUL (X2) -14.8 4.754       AGE (X3) 6.1 4.012         The hypothesis to be tested is:

You are performing an overhead shoulder press (picture). During the exercise, the torque produced by the arm/dumbbell weight rotates the shoulder into ________ .

Describe why performing a deep squat with heavy weights can aggravate the pain in individuals with patellofemoral pain syndrome. Make sure to explain your answer to receive a full credit.