Relating Chemistry to Healthcare and MORE ... - ACS Publications

Oct 9, 2017 - MORE in a Survey Organic and Biochemistry Course for Prehealth. Students. Lianne Schroeder,. †. Joshua Bierdz,. ‡. Donald J. Wink,. ...
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Relating Chemistry to Healthcare and MORE: Implementation of MORE in a Survey Organic and Biochemistry Course for Prehealth Students Lianne Schroeder,† Joshua Bierdz,‡ Donald J. Wink,‡ Maripat King,§ Patrick L. Daubenmire,⊥ and Ginevra A. Clark*,† †

Learning Sciences Research Institute, University of Illinois at Chicago, MC-057, 1240 W. Harrison, Chicago, IL 60607 Department of Chemistry, University of Illinois at Chicago, MC-111, 845 W. Taylor Street, Chicago, Illinois 60607, United States § College of Nursing, University of Illinois at Chicago, MC-802, 845 S. Damen Street, Chicago, Illinois 60612, United States ⊥ Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Road, Chicago, Illinois 60660, United States ‡

S Supporting Information *

ABSTRACT: We implemented a laboratory curriculum reform to teach foundational concepts in chemistry, particularly those concepts related to healthcare, in a chemistry course for prenursing students. Here, we discuss the reform, exploring how students built upon understandings gained in lab and correlating lab learning to course outcomes. We further discuss shifts in student work as they move through the course. As the course progressed, students became familiar with the pedagogy but also faced more challenging tasks. We present details on several of the laboratories that build the groundwork for understanding chemical principles, including the following: intermolecular forces, physical properties, acid−base chemistry, equilibrium, and chemical reactions. We further share our observations of student interactions around in-lab prompts and activities, and how these interactions inform our teaching. Our reform aims to improve critical thinking skills, namely, making and using models, observation skills, reasoning with evidence, and applying concepts to new problems. The laboratory procedures presented here modify those commonly found in the chemistry curriculum with a consistent student-centered pedagogy. We hope the simplicity and popularity of the lab procedures will allow for broad implementation of Rickey’s MORE (Model, Observe, Reflect, Explain) pedagogy, and we hope our lessons in implementation will broadly benefit those who are implementing new lab curricula. KEYWORDS: First Year Undergraduate/General, Curriculum, Interdisciplinary/Multidisciplinary, Laboratory Instruction, Organic Chemistry, Inquiry-Based/Discovery Learning, Applications of Chemistry, Equilibrium, Noncovalent Interactions, Nonmajor Courses



BACKGROUND

these understandings to healthcare. We have recently developed laboratories that illustrate chemical concepts in different healthrelated contexts, such as TLC to detect neonatal respiratory distress, computer modeling to understand protein structure, and competitive albumin binding to explain drug−drug incompatibilities.3−5 In our recent publications we have cited the importance of earlier efforts to educate students in both content and critical thinking.3,4 This report focuses on reforms from the organic portion of the course. This report aims to address the following questions: Has this laboratory curriculum supported students in understanding foundational concepts in chemistry and relating concepts to healthcare? Has this curriculum supported students in finding and using evidence? Were students

Project Goals

The shifting medical landscape in the US and abroad has placed increasing demands on nurses to critically assess patient needs. Liberal arts education must support the nursing student’s ability to connect foundational scientific concepts to complex realworld situations.1,2 The goal of this project was to teach foundational concepts of chemistry in the laboratory portion of a survey organic and biochemistry course. In particular, we aimed for students to understand chemistry concepts well enough to relate them to healthcare. In this paper we explore student progress over the first 8 weeks of an organic and biochemistry course in the context of three laboratories: distillation, synthesis of cyclohexene, and pH-dependent aspirin solubility. We describe how each lab worked toward our aim of teaching foundational ideas, improving students’ ability to find and use evidence, and relating © XXXX American Chemical Society and Division of Chemical Education, Inc.

Received: April 16, 2017 Revised: October 9, 2017

A

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of fetal distress.15 Aspirin and oil of wintergreen display pH-dependent solubility properties that relate to their absorption in the body under physiologically relevant conditions, and this is an ideal topic to explore in a chemistry course for nursing students.16

able to build upon understanding across different course contexts (i.e., from one lab to the next, on lecture-based exams)? Course Learning Objectives

Our work occurred in the context of a one-semester organic and biochemistry course that primarily enrolled prehealth, especially prenursing, students. It had a prerequisite of one semester of general chemistry that, for most students, included principles of stoichiometry, gas laws, solutions, and equilibrium (including acid−base equilibrium). This course aimed to teach five basic principles, chemical bonding and reactivity, equilibrium, acids and bases, intermolecular forces, and solutions, as well as a study of biomolecules/drugs. These concepts were identified as critical components of chemistry courses for nursing students.6,7 This paper reports on three laboratory experiences that we feel are fundamental to achieving the course’s aims of learning chemistry concepts coherently and in a healthcare context. The laboratory sequence (Supporting Information) supported these principles in various ways, with learning reinforced through lecture and discussion. For example, the first lab (distillation) was designed to help students understand the relationship between intermolecular forces (IMFs) and boiling points. This understanding was supported in lecture through discussions of electronegativity, polarity, Lewis structures, VSEPR, functional groups, and so on.8 We investigated how student success in lab supported their success in performing exam tasks that integrate lab and lecture-related skills. Later in the course, material was introduced that relied on a basic understanding of the relationship between IMF and physical properties (e.g., relating to pH-dependent solubility, principles of chromatography, and protein folding3). By developing these concepts in different contexts, we hoped to help students build a coherent understanding of chemistry rather than perceive chemistry as a series of disconnected facts.9 A key feature of this work was the collaboration between nursing faculty and chemistry faculty to ensure that we focused on chemistry content that was particularly troublesome for nursing students. Our nursing collaborator (M. King) observed nursing students’ lack of basic understanding of equilibrium manifested in their difficulty understanding dialysis, ion channels, competitive binding, or the more complex idea of homeostasis, which maintains equal concentrations in an open system (i.e., the relatively stable concentrations of oxygen and carbon dioxide in the blood, and related difficulty in monitoring arterial blood gases). Indeed, chemistry students are generally challenged by equilibrium concepts, failing to understand the dynamic process10 or understand equilibrium phenomena at all.11 The synthesis of cyclohexene lab (lab 4) provided students with an opportunity to explore chemical bonding and equilibrium concepts. This lab occurred at the point in the course when students were being exposed to their first organic chemistry reaction mechanisms and reaction principles. In the aspirin lab, students explored acid−base concepts: one of the most important chemistry topics for nursing students.6 Challenges in learning acid−base chemistry are known in the literature,12−14 and provide a basis for early lessons in the course. Our collaboration with nursing faculty has revealed that understanding pH-dependent membrane diffusion of drugs is a topic that frequently challenges nursing students. The pH-dependent properties of organic molecules can influence their distribution in the body, for example, influencing the relative concentration of anesthetics in fetal versus maternal blood under conditions

Generalizability and Contexts

The role of chemistry courses in prehealth education is shifting as the healthcare profession becomes increasingly technical, the nursing workforce faces shortages, and the value of “soft skills” is increasingly appreciated.17 Many nursing schools have reduced the prerequisites for chemistry instruction; similarly, the MCAT was recently revised to reduce the emphasis on organic chemistry.18 This change is often rationalized to allow for prerequisites that support other facets of healthcare, (e.g., statistics, computer programming, and psychology). Examination of laboratory reforms reveals few efforts to relate chemistry to healthcare for 100-level courses,19 despite the fact that many undergraduate students aim toward careers in health. Nevertheless, there is a need to structure courses so that prehealth students and colleagues in other disciplines value chemistry. With respect to the generalizability of this work, some of the laboratories reported here may be too complex for a one-semester general−organic−biochemistry (GOB) course and may be more appropriate for organic or biochemistry courses. Nevertheless, we have been developing laboratories to support several key chemical concepts that will be generally valuable: equilibrium, acid−base chemistry, physical properties, and chemical properties. We recently reported on a lab to relate intermolecular forces to protein structure.3 We further reported on a lab related to dialysis concepts and drug distribution.4 Development of several additional laboratories related to acid−base chemistry, carbohydrates, and chromatography is underway. By creating a series of refined laboratory experiments, and reporting on student development over the course of the semester, we hope to provide a guide for other practitioners in refining their courses to meet the dynamic needs of their programs and students. Frameworks and Pedagogy

This work is based on the use of the MORE (model−observe− reflect−explain) pedagogy, developed by Rickey and co-workers,20 and we recently reported a detailed study which includes an in-depth description of our frameworks, methodologies, and rationale.3 In this report, we describe how we applied these ideas across the curriculum. In the MORE pedagogy, students model a system of interest in both the molecular and macroscopic level. In lab, students make observations. Students then ref lect upon both their observations and their models, considering how their observations serve as evidence to support their models or support refinement of their models. Students finally use their understanding to explain the phenomena of interest or relate the phenomena to a similar system. This pedagogy is grounded in constructivist theories of learning, where the learner must find and use knowledge.21 Within the process of finding and using knowledge, students build upon their current understandings, resulting in deeper learning. Our project uses Design-Based Research (DBR) principles to both refine laboratory experiences for students and as a research tool to unveil student learning and misconceptions.22 We recently described using several rounds of DBR cycles to refine laboratories, resulting in improved student outcomes.3,4 In deviation from the work of others,23,24 we found that detailed prelab modeling prompts led to detailed (though often incorrect) B

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models. These prelab models revealed student misconceptions and resulted in improved postlab models. Further, we used prompts in lab to encourage students to draw what they observe, reflect upon how their observations support their models, and compare their work with that of other groups of students. In the current work, we made observations during lab in order to illustrate how students and teaching assistants (TAs) interacted around these prompts leading to improved understanding. In order to further understand the impact of our curriculum, we measured items to gauge student interest in chemistry across multiple iterations of our curriculum. This work also aimed to encourage student interest in chemistry, which is a key variable for success and retention in STEM.25 Students may be encouraged to effectively engage in chemistry practices by harnessing their interest in healthcare,26,27 and productive engagement with chemistry may increase interest.25,26 Scaffolds that help students to find and use knowledge in chemistry may support students’ developing interests. Similar approaches have proven helpful in reducing female and minority achievement gaps in STEM.26,27



Table 1. Number of Labs Collected and Analyzed for Each Experiment Experiment Name

Number of Laboratories

Week Implemented

Distillation of Liquids Synthesis of Cyclohexene Synthesis and Properties of Aspirin

22 27 34

1 4 8

implemented for each lab are provided in Table 1. The coders achieved an inter-rater reliability of 85% or greater across all laboratories. Application of Framework

Students were supported in their understanding of MORE with a video at the beginning of the semester to describe the MORE pedagogy. Further, prelab videos were created for several laboratories. (Prelab videos are available from the authors upon request.) Some of these videos were prepared solely by the course instructor,3 while others were prepared with our nursing collaborator.4 Students were provided with a laboratory handout, which was accessible from the course Web site. TAs were provided with detailed instructor notes, created through discussion with former TAs and analysis of student outcomes from previous semesters. These notes were the basis of weekly TA discussions that lasted approximately 50 min. As per the MORE framework,24 each prelab question included a prompt, an example of which is shown in Box 1.

METHODS AND IMPLEMENTATION

Description of Course

These laboratories were implemented in an organic and biochemistry survey course at a large midwestern university. The population of students at this university was roughly 40% under-represented minorities, with an average ACT score very close to the US average. Enrollment in this course was predominantly students preparing to apply to a top-caliber nursing program and predominantly female. The course followed a traditional sequence and was linked to a lecture course that employed a traditional textbook.28 In each week of the 15 week semester, students attend 2.5 h of lecture, 1 h of discussion with a TA, and one 3 h lab with a TA. The course covered approximately 10 weeks of organic chemistry and 5 weeks of biochemistry. The course schedule and a brief description of the laboratory curriculum is provided in the Supporting Information. Student survey responses from a presemester and postsemester survey were used to gauge student self-reported interest and ability in chemistry as well as the utility of lab as an instructional tool. This data was collected from FA13 to FA16, representing various stages in implementation of the reformed curriculum. Likert response items were examined for students who responded to both the pre- and postsemester surveys. The change in percentage of students who Agree/Strongly Agree with each statement is reported. Weekly surveys were also implemented, which included an open-ended response item asking students in what ways lab related to lecture.

Box 1. Pre- and Postlab Modeling Question Prompts Used throughout the Semester For this question, you will be graded on completion, rather than correctness of the model. In the postlab, you will be asked to evaluate your original models based on what you experienced in lab. In formulating your model, include macroscopic and molecular-level descriptions (in words and/or pictures). Postlab prompts were based upon the same question, but asked students to describe changes made to their models and evidence from lab that supported their models. Postlab prompts can be found in the Supporting Information as part of each lab handout.



RESULTS

Distillation Lab: An Introduction to MORE

During the first week of the semester, students separated acetone and isopropanol by simple distillation. The goal of this lab was to familiarize students with organic functional groups and the role of intermolecular forces (IMF) in determining boiling points. A foundational understanding of IMF and the ability to relate IMF to physical properties are foundational to understanding a number of more sophisticated topics in chemistry,8 such as chromatography,5 protein folding,3 and drug−protein binding.4 Each of these topics is relevant to nursing,6 but also to most careers in healthcare or the sciences. This was also the students’ first opportunity to use the MORE pedagogy. In the prelab, students were asked to draw the intermolecular interactions in each pure liquid and predict which molecule would have a lower boiling point (Figure 1). Students were further asked to draw a molecular and macroscopic picture of what occurs when a molecule boils, but that prompt was not included in our discussion, and it can be found in the Supporting Information. During lab, students were asked to

Collection and Coding of Student Work

Collection and analysis of student work was performed in accordance with a protocol approved by the university IRB. Identifying information was redacted from student work and replaced with a unique identifier. Collection of student work was performed within a single semester of implementation. Coding rubrics were developed for three laboratories (distillation, synthesis of cyclohexene, and synthesis and properties of aspirin) using the method previously described.3 Each rubric contained components that considered completeness (e.g., included macroscopic and microscopic representations) and correctness. Each lab was also coded for reflection components and use of evidence in supporting postlab models. Two coders evaluated the S16 student lab reports, where the number of lab reports collected and the week in the semester where the lab was C

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Figure 1. Distillation lab: modeling prompts and sample work. (A) Prelab question. (B) Student response to prelab question. (C) Student response to postlab question (from the same student). Student work was redrawn to improve reproduction quality and clarity. During-lab prompts and (same) student responses are provided in SI Figure S1.

reasoning.29 Many models failed to adequately consider the polarity of specific bonds in each structure, leading to errors. We observed that student notebooks were rich in observation data, such as descriptions of smells, and details about the rate of distillation. However, only 27% of students reflected upon their models during lab (Table 3). Nevertheless, most students

collect observations and reflect upon their models. In the postlab, students were asked to use evidence (boiling points) to support or refute their model. We found that 95% of students completed the prelab modeling activity, even though it was implemented in the first week of the semester and about a third of the class attended lab before the first lecture (Table 2). A majority of students (63%)

Table 3. Student Use of Reflection and Evidence in the Distillation Lab

Table 2. Distillation Lab: Student Improvement of Pre- and Postlab Intermolecular Force Models Degree of Completeness or Correctness Student made an attempt that includes all required components (correct or incorrect) Student drew two molecules to represent IMF (correct or incorrect) Student correctly modeled IMFa

Prelab, %b Postlab, %b 95

100

63

77

36

50

a

a

Significant improvement from prelab to postlab based on t test for two dependent means (t = 2.6, p = 0.016). Each lab scored 0−3 according to components above (1 = attempt, 3 = correct) to generate a score for the t test. bN = 22.

Description of Student Action

Students, %a

Predicted that acetone has lower boiling point (prelab) Reflection during lab completed Used evidence (boiling points) to support or correct model

77 27 91

N = 22.

(91%, Table 3) used the boiling point evidence to support their models in the postlab. This finding suggests that, during this first lab, students struggled to connect in-lab reflections to their model, but were successful at connecting the model to evidence in the postlab. Further, many students (43%) with incorrect prelab models improved their models in the postlab, suggesting that lab provided an opportunity to discuss Lewis structures and intermolecular interactions that led to improved understandings. Figure 1 shows a model of student work that failed to properly analyze polarity in the prelab, but was corrected in the postlab. This student further used the evidence of lower boiling points to support their understanding. This student’s responses to during-lab prompts are provided in the Supporting Information. The student engaged in observation, but not reflection during lab. We aimed to establish relationships between student lab performance and in-class performance on related topics. We studied responses to an exam question that asked students to draw primary and tertiary amines and explain which would have a higher boiling point (Box 2). As shown in Table 4, students who correctly drew IMF in their postlab were the most likely to correctly draw IMF for both the primary and tertiary amines.

used two molecules in their prelab models (Table 2), but only 36% of students properly drew intermolecular interactions for both isopropanol and acetone. The fact that students used two molecules was encouraging, since other reports showed that students frequently represent intermolecular interactions using a single molecule.29 The use of two molecules was prompted in both the lab handout and the prelab video, suggesting that students used these materials in making their models. However, students’ inability to properly draw intermolecular interactions highlights the challenge of Lewis structures and IMF for students. In the prelab, most students (77%) correctly predicted that acetone has a lower boiling point since isopropanol forms H-bonds and has stronger IMF, though most students were unable to properly illustrate intermolecular interactions. This finding suggests that students’ understanding of IMF was at the surface level. While they could state the relationship between boiling point and IMF, they did not understand the underlying principles and followed a simplistic “more is more” D

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(Table 5). Importantly, we found that students did engage in reflection during lab, as indicated by both laboratory notes and in-lab observations. While only 36% of initial models were correct, students improved their models, with 80% having correct molecular-level representations in the postlab. These results suggest that students’ early experiences with MORE improved their ability to generate and refine more sophisticated models, which in turn facilitate their understanding of complex ideas. When examining students’ notebooks, we find that many students drew pictures of their observations during lab, such as drawing shifts in the solution volumes of reaction and receiving flasks. Further, students engaged in reflection during lab, considering how evidence can be used to support their models. This data is provided in Table 6, and an example of student inlab observations is given in Figure 3. Most students (88%) identified two layers (water and cyclohexene) in their collected product, with 52% of students further indicating how this observation can be used as evidence to support their models (Table 6). We also observed students in lab as they discussed their observation of two layers in the separatory funnel, the chemical significance of adding sodium chloride solution to their product, and its relation to their models. The transcript of this conversation is provided in Box 3 and illustrates that

Box 2. Distillation Exam Question: Drawing and Representing IMF for Amine Compounds (a) Draw three unique molecules with the molecular formula C3H9N. Indicate if each molecule is a primary, secondary, or tertiary amine. (b) Draw a picture to describe the intermolecular interactions between primary amine molecules. Be sure to label your picture. (c) Draw a picture to describe the intermolecular interactions between tertiary amine molecules. Be sure to label your picture. (d) Based on your drawings, which do you expect to have a higher boiling point, primary or tertiary amines? Explain your answer. Table 4. Students Performance on Exam Question Related to Model of Intermolecular Forces Students Correctly Answering IMFRelated Exam Questions, % Primary Amine

Tertiary Amine

Question Status on IMF in Postlab Model (Acetone/n-Propanol) Structure

IMF

Structure

IMF

Did not use 2 molecules (n = 5) Drew 2 molecules, but incorrect (n = 6) Drew 2 molecules, correct IMF (n = 13)

0 67 84.6

0 100 84.6

0 50 61.5

20 100 84.6

Box 3. Cyclohexene Lab: Conversation between Students Regarding Layers Observed

Only one student who did not draw two molecules in the postlab was able to perform any portion of the exam question correctly. Even though the Distillation Lab was the first lab of the semester, we found a relationship between success in this lab and success on the exam. Half of the students who used two molecules but incorrectly drew IMF on their lab report were successful on the exam question, suggesting they used in-class opportunities to build upon their understandings.

S1: How many layers? S2: There’s two layers S1: Are your observations consistent with your prelab model? S2: We added sodium chloride to decrease solubility of cyclohexene in water. And this got bigger when we added NaCl. S1: Bottom layer got larger. S2: The aqueous layer is the bottom because the NaCl dissociated in the water, which makes it...

Cyclohexene Lab: Organic Reactions and Equilibrium Concepts

In this lab, students performed an elimination reaction of cyclohexanol to produce cyclohexene and water. Since the products have a lower boiling point than the reactant, the reaction can be driven to completion by product distillation, providing a clear illustration of Le Châtelier’s Principle. To support the relationship between equilibrium concepts and healthcare, M. King was presented in the prelab video describing homeostasis concepts in relation to oxygen levels in a gunshot victim’s blood. We implemented multiple iterations of this lab, and found that students had immense difficulty in understanding the application of Le Châtelier’s principle to a distillation reaction. For example, students used equilibrium arrows to indicate a relationship between the contents of the reaction flask and receiving flask; indicated that, at the midpoint, the entirety of the reaction was the carbocation intermediate; or suggested that the reaction volume increases as product forms (data not shown). Many students suggested that the only reason to perform a distillation would be to purify products. Indeed, these student experiences highlighted the divide between students’ surface-level understanding of Le Châtelier’s principle11 and their ability to relate this principle to a laboratory experience. Over time, we refined the lab with the prelab modeling questions shown in Figure 2 to ask for multiple macroscopic and molecular-level representations, where most students (96%) were able to generate a complete model in the prelab

students use the in-lab prompts to improve their understandings. The value of specific prompts to engage students in observation and reflection was recently reported, and this study provides evidence that these prompts can be applied across a variety of lab types.3 We also found that reflection during lab was scaffolded by the TA. After students collected their pure cyclohexene, students added bromine to verify that they synthesized cyclohexene. The addition of bromine results in an addition reaction, leading to 1,2-dibromocyclohexane, providing students with evidence for a claim that they made cyclohexene during the distillation reaction. Due to bromine toxicity, the TA added bromine to the flask for each group of students, allowing for a more in-depth conversation to occur. Students struggled initially to connect the observation of color change (i.e., loss of bromine color) as evidence that a reaction occurred. TA dialogue presented in Box 4 between a student and the TA illustrates some of the challenges students faced in making good observations and understanding their observations in the context of a chemical reaction. Indeed, we see in the example provided in Figure 3 a student who was not able to make good use of observation in understanding the bromine experiment, and only 40% of students successfully used this data as evidence to support their understanding (Table 6). E

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Figure 2. Cyclohexene lab. (A) Prelab prompt (student work completing reaction shown in blue). (B) Student (partially correct) response in postlab. Student work was redrawn to improve reproduction quality and clarity.

Table 5. Cyclohexene Lab: Students’ Macroscopic and Molecular Representations in Pre- and Postlab Modelsa

Table 6. Observation and Reflection Behaviors During the Cyclohexene Lab

Macroscopic Representation Status of Model Attempted Illustrated change in volume over time

Prelab, %

In-Lab Observation: Separatory Funnel

Postlab, %

Drew and identified two layers 88 Connected to model indicating that two products are 52 present In-Lab Observation: Bromine Reaction Identified Features, %a

92 92 64 80b Molecular Representation

Status of Model

Prelab, %

Postlab, %

Attempted Correct structures and changes Correct structures, changes, stoichiometry

96 32 20

100 80c 44d

Identified Features, %a

Attempted to use evidence Correctly interpreted color change Connected evidence to model Postlab Uses of Observation and Reflection

a

N = 25, tested for significance based on Z-score for two population proportions (one tailed). bNot statistically significant. cZ = −3.4, p = 0.0003. dZ = −1.8, p = 0.03.

84 68 40 Identified Features, %a

Used observation as evidence in postlab (two-layers OR bromine) Correct response to postlab question (not distilled)

Importantly, we found that 88% of students reflected during lab on at least one piece of evidence (two layers or bromine test) to support or improve their molecular-level model (Table 6). Overall, 80% of students successfully represented the molecular and/or macroscopic representations in the postlab (Table 5). Further, 76% of students correctly answered a postlab question regarding what would happen if the reaction was performed in a single container and not distilled (Table 6 and Box 5). This suggests that students were able to understand their models and apply this information to similar systems. Of note, only 44% of students showed consistent stoichiometry in their postlab (Table 5). For example, the student work in Figure 2 showed four molecules in their initial flask, then nonstoichiometric yields as the reaction proceeded. We have modified TA notes and student prompts to improve this result. We recognize that

88 76

models are by definition approximations, where certain information is highlighted over other pieces of information. For the novice student, stoichiometric accuracy may not have been valued to the same extent as it would be for an expert. Aspirin Lab: pH-Dependent Solubility and Drug Absorption

In this lab, students complete the synthesis of aspirin and oil of wintergreen to help solidify their understanding of ester and anhydride chemistry. This chemistry is foundational to understanding transcription, translation, and DNA synthesis, which are studied later in the course.28 In addition, students examine the pH-dependent solubility of their products to better understand principles of drug absorption. The topic of pH-dependent drug absorption was identified by F

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Figure 3. Cyclohexene lab. (A, C) During-lab prompts to observe two layers and during bromine test, respectively. (B, D) An example of student response to the prompts. Student work was redrawn to improve reproduction quality and clarity.

Box 4. Cyclohexene Lab: TA Interaction with Students about Bromine Test TA: What are the characteristics of a chemical reaction? Student: A color change? TA: A color change. What else? (Pause) Here, you have the bromine that is brown. Your initial reaction was clear. After mixing of the two you go back to something clear. Student: There was no reaction? TA: You mix something that is brown with something that is clear and after mixing, it is back to clear. What Student: There was a reaction. TA: There was a reaction because you have disappearance of the color of bromine. That means that the bromine reacted with the compound that is inside. Okay? (Pause) If the bromine reacted with the compound that is inside, what does that mean? What was the initial question to do this test? Student: It is a cyclohexene. Figure 4. Aspirin lab. Prelab prompt and student response in postlab. Student work is shown in blue and was redrawn to improve reproduction quality and clarity. Student drawings and explanations are partially correct.

Box 5. Postlab “Explain” Prompt Consider what would happen if this reaction was done in a single container (not distilled). Draw what would be in the flask after the reaction has reached equilibrium. Remember that this is a reversible reaction.

Table 7. Aspirin Lab: Student Postlab pH-Dependent Solubility Models Representation at pH Value, %a

our nursing colleagues as particularly difficult for students to understand and also relevant to their chemistry coursework. This example provided an opportunity to connect organic chemistry concepts to material that students will learn in a pharmacokinetics course, typically taught in their junior year of nursing school.16 We have devised a different application of the MORE framework, to scaffold students in understanding of the pH-dependent solubility of aspirin in the digestive system. The prelab modeling question asked students to show the structure of aspirin at different points in the digestive system (at a given pH) (Figure 4). Table 7 summarizes student responses to this modeling question. Most students (82%) were able to show that, at low pH (pH = 2), aspirin will be protonated and insoluble in water. Further, most students (65%) were able to

a

Status of Model

2

3−5

7.4

Attempted Correct protonation state Correct explanation (e.g., Figure 4)

94 85 41

94 44 26

94 74 35a

n = 34.

show that, at high pH (pH = 7), aspirin would be deprotonated and soluble in water. Figure 4 is an example of a typical student who had correct protonation states and explanations at some pH values. Less than half of students were able to connect solubility to the concept of drug absorption. Students struggled most with representing and explaining the protonation state of G

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aspirin when the pH of the solution was near the pKa of aspirin. Only 26% of students included both protonated and deprotonated states in their postlab models. Further, few students were able to explain the role of equilibrium between the protonated and deprotonated forms in rapid aspirin absorption. Our view is that most students did not have enough time in lab for reflection, and we will reimplement with this lab split over 2 weeks. Nevertheless, we demonstrate that students who developed a clear understanding of membrane permeability in lab were able to apply these principles to a related exam question (Box 6). Box 6. Aspirin Lab Exam Question: Below Is the Structure of Cocaine

Figure 5. Change in percentage of students who Agree/Strongly Agree with each of the Likert response items from presemester to postsemester. A positive value means that more students Agree/ Strongly Agree in the postsemester survey. In FA13, FA14, and FA15, there was no change in the percentage of students who “Agree” or “Strongly Agree” to the question “Chemistry is important for nursing”.

the Supporting Information. Early in our iterations (FA13−SP14), students were less likely to report lab as helpful at the end of the course than they were at the beginning. As our project progressed, students became more likely to report lab as helpful in the postsemester survey. In all iterations, students reported “liking” and being “good” at chemistry at higher rates after taking the course. In every iteration, over 80% of students “Agree” or “Strongly Agree” that chemistry is important in nursing. We note in the last three iterations that more students identify chemistry as important after taking the course. These are by no means exhaustive measures of student attitudes toward chemistry, and we would caution against applying statistical analysis to this data.31 However, taken together they suggest that, through course improvements, students’ interest in chemistry increases, their confidence increases, they see increased value in chemistry, and they report lab as useful for learning chemistry.

Students’ understanding was demonstrated through a prelab question about the absorption of oil of wintergreen through skin. Students who demonstrated a good understanding of the absorption of oil of wintergreen through the skin performed better on the exam question than students who did not (Table 8). Table 8. Aspirin Lab: Student Performance on Exam Question Related to Absorption Student Status on Oil of Wintergreen in Postlab

Cocaine Absorption Question Meana(SD)b

Not attempted/incorrect n = 10 Correct explanation, n = 24

2.70 (1.48) 4.38 (1.55)

a

Out of 6 possible. bp = 0.002.



Student Interest in Chemistry

DISCUSSION AND CONCLUSIONS Here we described our implementation of the MORE pedagogy in an organic and biochemistry course. Students’ ability to make and refine models improved over the first 8 weeks of a 15 week semester. For example, in the distillation lab (week 1) 50% of students refined their models, whereas 88% of students refined their models in the cylcohexene lab (week 4). We also observed students using the in-lab prompts as the semester progresses, both to improve their models and to use evidence in supporting refinement. Students’ ability to make and use models improved as the semester progressed and was correlated with their understanding of course content. For example, students who used two molecules to demonstrate IMF performed better on an exam-related question that required additional learning from other elements of the course. Student learning from the distillation lab likely supported student learning in later laboratories, for example when we asked students to draw two amides H-bonding in a computer modeling lab.3 In our computer modeling lab, we found that 90% of students drew two molecules in the prelab,

Critical to our efforts is that students see the value in chemistry and how chemistry can be used to understand various phenomena. We find that many students were supported in their understandings, as one student reported in their weekly online survey: The Aspirin lab helped introduce the concept of how various drugs and compounds are absorbed by the body, how these compounds interact with each other, and why it is important to know all this chemistry. Further, we examined student response to 5-point Likert response items (“Strongly Disagree”, “Disagree”, “Neither Agree nor Disagree”, “Agree”, “Strongly Agree”) regarding students’ perceived interest and ability in chemistry, as well as the value of lab (Figure 5). These questions are similar to those presented to calculus students in work by Bressoud and co-workers,30 but with strikingly different results. We report the change in percentage of students who “Agree” or “Strongly Agree” with each statement from the presemester survey to postsemester survey over several semesters of lab implementations. Percentages of students who agree/strongly agree in the pre- and postsemester survey data and with n values for each semester are provided in H

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but only 40% correctly drew the H-bonding pattern.3 While our modeling report was on students from a different semester, our finding that 90% of students draw two molecules is in striking contrast to other reports on unreformed classrooms, where only 46% of students drew two molecules.29 Further, student understanding of chemical equilibrium was developed throughout the course in several ways, built largely on lessons from the cyclohexene lab. These lessons were used later in the semester to help students develop models for dialysis4 and competitive albumin binding,4 concepts that are directly linked to healthcare. Further, we worked to develop student understanding of equilibrium in pH-dependent drug absorption. We demonstrated that students who understood oil of wintergreen absorption understood not only pH-dependent cocaine solubility, but also its volatility. Relating charge to volatility was not directly discussed in the course, so solving this problem requires students to integrate knowledge across the semester. A limitation of this study is that it was performed in one context in which the course instructor was also responsible for lab implementation in a medium-sized classroom. The influence of instructional changes in lecture cannot be separated from lab, but nevertheless this implementation emphasizes the connection between lab and lecture. Further, that students retained and built upon material in the course does not a prioi mean that students retain and build upon this information later in their academic or professional careers. This paper discusses three laboratories that are generally very close to those found in the typical GOB curriculum, but focus student understanding to foundational concepts that might be missed in a traditional lab. We hope that the similarity of the methods will allow for adoption of our pedagogy. We demonstrate how the use of this pedagogy when paired with classroom learning helped students to find greater value in chemistry and their laboratory experience. In this sense, students followed the same trajectory in using the laboratories as we followed in building the laboratories, with more nuanced learning occurring with each opportunity to engage in the curriculum and application to healthcare occurring as foundational understandings are defined. We have demonstrated the progress we have made toward developing a laboratory curriculum based in our three guiding principles: teaching fundamental concepts, using an appropriate pedagogy, and connecting chemical concepts to healthcare. Over the course of a semester engaging in these lab activities, we see improvements in students’ understanding of fundamental concepts in chemistry.



Present Address

(J.B.): Biomedical visualization graduate program, University of Illinois at Chicago, MC-530, 1919 W Taylor St Suite 250, Chicago IL, 60612 Notes

The authors declare no competing financial interest.



ACKNOWLEDGMENTS The material is based on work supported by the National Science Foundation under Grant DUE-1431926. The authors would like to thank the teaching assistants who have participated in this study for their insights and efforts. The authors would further like to thank the students who have performed this lab.



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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00272. Supplementary figures, tables, and laboratory handouts used in the study (PDF) Synthesis of cyclohexene lab (DOC) Distillation lab (DOCX) Aspirin and oil of wintergreen lab (DOCX)



REFERENCES

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Ginevra A. Clark: 0000-0003-3065-2627 I

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