This figure shows the fraction or percent of myoglobin or hemoglobin O2 binding sites occupied on the y-axis as a function of O2 partial pressure shot on the x-axis. The middle Hb blue curve is for normal Hb. The right-hand red Hb curve reflects the shift in the bonding affinity of Hb in response to a drop in pH, whereas the left-hand green Hb curve reflects the change in response to an increase in pH.     Diagram citation Wikimedia Commons (Public Domain)  Image Description  Graph depicting hemoglobin oxygen saturation percentage against oxygen partial pressure (mmHg). Three curves represent different pH levels: green for pH 7.8 (alkalosis hypocapnia), blue for pH 7.4 (normal), and red for pH 7.0 (acidosis hypercapnia). The y-axis ranges from 0 to 100%, indicating hemoglobin oxygen saturation, while the x-axis ranges from 0 to 120 mmHg, indicating oxygen partial pressure. The curves show the relationship between oxygen binding and blood pH. Which of these curves shows the greatest affinity for O2? (1 pt.) Which one of the two shifted Hb curves, right or left, would result in the release of the most O2 to the cells, if the lung pO2 decreases from 100 torr to 60 torr and the pO2 of the tissues remains the same at 27 torr? Briefly justify your answer. (2 pts.)

A random sample of 525 Penn State students were asked whether they are originally from Pennsylvania. We will study those that responded “yes”. The following Minitab output summarizes the results of those that responded “yes”. Examine the descriptive statistics provided above, which statement is NOT true?

Upload your answers to these questions. Outline the synthesis of the ketone body, acetoacetate, which forms in the liver under fasting conditions. It is formed in three steps. Include all substrate and product names and structures, enzyme names, and any necessary cofactors or coenzymes. (6 pts.) For the last step in the synthesis of acetoacetate, draw the arrow pushing mechanism for the reaction and identify which reaction in glycolysis it is parallel to. (3 pts.)  Ketone bodies are exported from the liver and utilized as an energy source by the extrahepatic tissues. The brain, which normally utilizes glucose as its energy source, can, under fasting conditions, partially convert to using ketone bodies over the course of a few days. Show how a molecule of the ketone body, -hydroxybutyrate, produced in the liver and exported via the blood to the brain, is utilized for energy production and what advantage this compound has over acetoacetate in terms of cellular energy production. You may use compound names instead of structures. Enzyme names are not necessary. Include any necessary cofactors for full points. (3 pts.) 

 Questions 14 – 17 will refer to the same research scenario. A delivery company has asked a random sample of delivery drivers to report the number of miles driven on Wednesday 8/6/2025. The data was summarized with the following box plot. How would you describe the shape of the distribution?

The amino acids Gly and Pro, as well as modified prolines that have a hydroxyl group on the Pro ring or Hyp, are the principal amino acids comprising collagen. Consider this excerpt from this article: Beck, K., Chan, V. C., Shenoy, N., Kirkpatrick, A., Ramshaw, J. A. M., & Brodsky, B. (2000). Destabilization of osteogenesis imperfecta collagen-like model peptides correlates with the identity of the residue replacing glycine. Proc. Natl. Acad. Sci. U.S.A. 97 (8) 4273–4278. “Gly-Pro-Hyp is the most common, as well as the most stabilizing, triplet in collagen (5). The presence of Gly at every third residue is considered essential….” If there is a genetic mutation that interrupts this pattern of Gly at every third position, bones do not develop properly. They are characteristically brittle, resulting in a genetic disease known as osteogenesis imperfecta. Use your knowledge of the structure of collagen to explain why this regularly repeating Gly residue is essential to the formation of a proper and strong collagen triple helix.  (2 pts.) Vitamin C is required for the biochemical reaction that puts the modifying OH group on a Pro in collagen. Why does a vitamin C deficiency result in changing the overall strength of collagen? (2 pts.)

A researcher wants to estimate the average high temperature during the month of July in Rochester, NY. Over the past 10 years, the researcher recorded the high temperature for each July and, with the data, the following Minitab output produced: A. Provide a statistical interpretation of the confidence interval written in the context of the problem. [3 points]B. How can we determine if we are able to meet the normality assumption? Explain your reasoning. [2 points]C. What is the point estimate for the confidence interval? [2 points]D. The local newspaper wants to report that with 95% confidence, the true mean July high-temperature in Rochester, NY is at least 80 degrees. Is this reasonable to say with 95% confidence? Explain. [2 points] E. Discuss how the confidence interval formula would change if we, instead, built a 99% confidence interval. Also indicate how this change affects the overall interval. [2 points]

The figure below is of the x-ray structure of this peptide. Residues 37 and 18 interact with each other. Identify the type of bond or interaction that they (residues 37 and 18) have (i.e., covalent, ionic, hydrogen bond, and so on), and state whether a link like this would be most likely to be found in a peptide exposed to an oxidizing environment, a reducing environment, or no effect. Image Description  A 3D protein structure showing the positions of cysteine residues (Cys4, Cys11, Cys18, Cys30, Cys36, and Cys37) highlighted in yellow. The protein has an N-terminal (N) and C-terminal (C) with distinct secondary structures: alpha-helices in red and beta-sheets in blue, connected by green loops. The cysteine residues form disulfide bonds, contributing to the protein’s stability and shape.

  Image Description The picture depicts the structure of epinephrine. It consists of a six-membered benzene ring with three substituent groups. Attached to the bottom carbon of the ring, the 4 position, is a hydroxyl group. Attached to the lower left carbon of the ring, the 3 position, is a hydroxyl group. Attached to the top carbon of the ring, the 1 position, is CH(OH)CH2NHCH3.   The structure of the hormone epinephrine (adrenaline) is shown. Which common biomolecule would best serve as the starting material for synthesizing this compound? Give the structure, name, or abbreviation.  (1 pt.)    Epinephrine acts on liver cells through a G protein-coupled receptor and acts similarly to the hormone glucagon. Does the action of epinephrine promote the synthesis or breakdown of glycogen?  (1 pt.)    Both epinephrine and glucagon activate the same intracellular messenger, 3’,5’-cyclic AMP (cAMP). Explain how increased levels of cAMP in the cell are able to control both the synthesis and breakdown of intracellular glycogen, beginning with GTP bound to the α-subunit of the G protein receptor. (4 pts.) 

A random sample of car ads were studied and the horsepower​ and car’s selling price were collected. ​You have obtained the graph and regression equation below to determine if the horsepower can be used to predict a car’s selling price. Car Price = 3643 + 67.91(Horsepower) What does the slope of the line indicate?

Questions 10–12 You’ll answer the questions by typing the letter that corresponds with the correct answer. This table will also be in a dropdown for each question. Identify these cofactors or coenzymes and, from the metabolic reactions we have encountered, name a reaction or enzyme that requires the cofactor. 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, but you only need to select one example that is correct. That is, you can only pick one answer even if there is more than one that would be correct. Molecule Names Enzymes and Reactions A. acetyl-CoA K. acetyl-CoA carboxylase B. acyl carrier protein L. carnitine acetyltransferase  C. biotin M. citrate lyase  D. carnitine N. citrate synthase  E. cobalamin O. dehydrogenase F. coenzyme A P. fatty acid synthase G. GDP Q. fatty acyl CoA synthetase H. HMG-CoA R. hydratase I. NADPH S. isomerase  J. NADP+ T. methyl malonyl mutase U. propionyl-CoA carboxylase  V. pyruvate carboxylase  W. racemase  X. thiolase