1 of 3 Biological Sciences 103 Winter, 2014 K. Hilt Answer


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I have attached questions , but don’t know how answer came. ATTACHMENT PREVIEW Download attachment 3 pages bis 103 homework #1 key.pdf 1 of 3 Biological Sciences 103 Winter, 2014 K. Hilt Answer Key Homework #1 Learn the structures, enzyme names, cofactor/coenzyme requirements, and regulation of glycolysis (see page 2). Be able to draw the structure of a triglyceride, phosphatidylcholine, and phosphatidylserine with any of the five fatty acids attached: 16:0, 18:0, 18:1(9), 18:2(9,12), and 18:3(9,12,15); palmitic, stearic, oleic, linoleic, and α-linolenic, respectively. Assigned problems in Biochemical Calculations (Segel): 1. Lineweaver-Burk plots: example 4-9 on page 237; #10 on page 320 2. Beer’s Law calculations: example 5-4 on page 332; #4 on page 352 3. K/eq and ΔG calculations: examples 3-3, 3-4, and 3-5 on pages 161 – 164 1. Learn the laboratory steps needed to conduct a DNA microarray experiment. Go to http://learn.genetics.utah.edu/content/labs/microarray/. Click on the microarray image and go through the three chapters that are listed. Answer the questions that they have at the end of their chapter 3. The whole interactive laboratory exercise should take 30 minutes or less to complete and will strengthen your understanding of DNA microarray experiments. (Your computer will need the program “Active X” to run the laboratory exercise. You may already have this program. If not, download it for free from the internet). 2. A microcalorimetry experiment was done on some spinach leaves, following the same protocol that we discussed in lecture. Draw in carefully the expected results if the spinach leaves yield a heat rate of 75 μW/mg and then show a 20% increase in heat rate when 0.4 N NaOH is added to the interior container in the ampule. What would the plots look like if the same mass of spinach leaves, but treated with pesticide for thirty minutes before measuring, gave a 30% decrease in heat rate/mg, but the same heat rate/mg in the presence of 0.4 N NaOH? What do you conclude about the effects of the pesticide on the spinach leaves? Refer to your notes on how to make the above plots. Treatment of the leaves with pesticide is eliminating the CO2 production. Not a good thing. 3. A student runs an enzyme assay using the anaerobic glycolytic enzyme, lactate dehydrogenase (LDH). Their 1 ml assay is: 900 μl 200 mM Tris, pH 7.3 35 μl 30 mM pyruvate (in H2O) 35 μl 6.6 mM NADH (in H2O) 30 μl of their LDH solution, in 200 mM Tris, pH 7.3 They mix everything gently together in a cuvette and then measure the ΔA340/Δtime using a spectrophotometer. Their measured ΔA340/30 sec. was “-0.0311”. a) On the enzyme kinetic graph, what is plotted on the x and y axes? Refer to your notes. b) What does the “-” in “-0.0311” tell you? The compound that you are measuring is being consumed. 2 of 3 c) How many I.U.’s of LDH were present in the 30 μl that you added? εNADH, 340 nm = 6220 M-1cm-1. 0.01 I.U. (continued) 3. d) Let’s say that the total time of your LDH assay was 2 minutes. Did the pH of the assay change much during that time? Show a calculation. (Model your calculation after questions #40 and #41 on page 93 of Biochemical Calculations). The pKa of Tris is 8.21. No, the pH remained at 7.3. Use two HendersonHasselbalch equations. Include the volume of the enzyme solution as part of your buffer. e) If the pH changed in part “d” above, what would you do to minimize the pH change? Give three different answers. One answer would be to run the assay for a shorter period of time. You think of two other answers. f) You need to make up 500 ml of 200 mM Tris buffer, pH 7.3, in order to run your LDH assays. You have a 1.0 M Tris solution, pH 9, and 1.0 M HCl and 1.0 M NaOH. How will you make up the buffer? 100 ml 1.0 M Tris, pH 9 + 75 ml 1.0 M HCl + 325 ml water g) Let’s imagine that your LDH enzyme has a Km for NADH of 40 μM and a Vmax of 80 nmoles x liter-1 x min . What would your Lineweaver-Burk plot look like? (Draw it). Label your x- and y-axes,

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