RPE65 is a major protein of unknown function found associated with the human eye that is associated with a number of different eye diseases. One hypothesis is that RPE65 is an enzyme involved in the chemical synthesis of the pigment that makes the human eye light sensitive. In a search as to which pathway intermediate RPE65 acts on, the following dissociation constants were measured (Table 1). They were compared to BSA, which stands for bovine serum albumin and is found in large concentrations in cow milk. Table 1:  Binding Constants of Various Retinoids with RPE65 and BSA in pM (10^-12 M). The numbers in brackets (  ) indicate the errors of the binding constant determination. Ligands RPE65 (pM) BSA (pM) A: all-trans-retinyl palmitate 20 (6) 2143 (790) B: 11-cis-retinyl palmitate 14224 (3006) 2310 (611) C: all-trans-retinol 1078 (144) 2316 (1216) D: 11-cis-retinol 3811 (100) 2143 (800)   Part A. 4 points What is the purpose of comparing the dissociation constants of 4 different ligands with two different proteins, RPE65 and BSA?  Part B. 5 points What is the association constant for 11-cis-retinol binding to RPE65? Part C. 5 points What is the difference in standard binding free energy between ligand A binding to RPE65 as compared to BSA. Part D. 4 points Which is the best (highest affinity) ligand for RPE65? Justify your choice. Part E. 4 points Would you say that RPE65 binding to any of the ligands is specific? Justify your answer. Part F. 10 points If you add a 10 nanomolar concentration of ligand A to a solution containing RPE65, what percent of ligand A is bound to RPE65? Part G. 10 points If you repeat the same experiment as in part F with BSA, i.e. if you add a 10 nanomolar concentration of ligand A to a solution containing BSA, what percent of ligand A is bound to BSA? Solve this problem on paper, document your approach and provide intermediate results.  Report the final answers with 3 significant figures.  Scan the pages(s) and upload them for grading. Answer all parts A to G.

The examiner should expect the ratio of respiratory rate to heart rate to be approximately:

The client has a gastrostomy tube for enteral feedings. Which of the following statements are correct regarding enteral nutrition (EN). (Choose all that apply)

The nurse notes that a preoperative client is drowsy, but oriented, in the holding area. Because of her drowsiness, the nurse should identify the client using which of the following methods?

The decision of the Supreme Court in Roe v. Wade was based on:

The nurse is instructing a group of young adults. When talking about fiber and its relationship in preventing colon cancer, the nurse explains which of the following actions for fiber?

Costovertebral angle tenderness should be assessed whenever you suspect the patient may have:

Convert 98.7 Fahrenheit to Celsius degrees. [BLANK-1]

The nurse enters a client’s room and notes that he has tube feeding running at 50 ml per hour. If the head of the bed is flat, the nurse understands that the client is at risk for which of the following?

Which of the following is associated with the “pseudogallbladder” sign ?