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The Molecules that Make Me Unique

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Abstract

As a fifth-year teacher in an urban middle school, I have become keenly aware of how important it is to provide my students, who are predominantly African American, with culturally responsive classroom experiences. In this application of socially transformative science curriculum, I began with a traditional lesson on atoms, molecules, and compounds and modified two activities within the lesson. Explanation (20 minutes) The explanation portion of the lesson is aimed at facilitating students' understandings of the differences between atoms, molecules, and compounds. To begin this portion of the lesson, students are provided with a Venn diagram featuring bubbles for molecules, compounds, and atoms as well as brief descriptions of each (see Figure 2). [Extracted from the article]
BY JOMO MUTEGI AND VANESSA GEE
As a fth-year teacher in an urban middle school,
I have become keenly aware of how important
it is to provide my students, who are predomi-
nantly African American, with culturally responsive
classroom experiences. Unfortunately, there are not
many resources that support the application of these
approaches to science instruction.
44
CONTENT AREA
Physical Science
GRADE LEVEL
6–8
BIG IDEA/UNIT
Atoms, molecules and
compounds
ESSENTIAL PRE-EXISTING
KNOWLEDGE
None required
TIME REQUIRED
95 minutes
COST
Minimal (<$20)
SAFETY
Students should wear safety
goggles when working with
models.
content mastery is essential for students
to have access to science and science-
related professions. Second, students
should develop a mastery of currency,
which is to say that they should devel-
op an understanding of how the con-
tent is relevant to human beings. Third,
students should develop a mastery of
context, which refers to students’ under-
standing of how the content is related to
them. This area of mastery is important
because it helps students to see them-
selves represented in the curriculum.
This can be accomplished by introduc-
ing them to signicant people, places, or
events (whether historical or current).
Fourth, students should develop a
mastery of critique, which refers to stu-
dents’ ability to be critical consumers
and producers of scientic knowledge.
Here students should learn to recog-
nize shortcomings, unseemly inuenc-
es, and aws in scientic practice and
in the application of scientic knowl-
edge. Finally, students should develop
a mastery of conduct, in which they
learn practical skills for the application
of science knowledge. It is not neces-
sary for each lesson to encompass all
ve areas of mastery. The goal should
be to infuse as many as are reasonable.
In this application of socially trans-
formative science curriculum, I began
with a traditional lesson on atoms, mol-
ecules, and compounds and modied
two activities within the lesson. The
rst modication was aimed at helping
students develop mastery of context,
which in this case refers to an under-
standing of how atoms, molecules, and
compounds relate to them as people
of African descent. The second modi-
cation was aimed at helping students
develop a mastery of critique, which
encouraged them to pay close attention
to the limitations of the models we use
Then one summer I was selected
to participate in a Research Experi-
ences for Teachers (RET) program.
The program gave me an opportu-
nity to conduct lab-based research. It
also required that I (along with nine
other teachers) develop a culturally
responsive curricular module, apply-
ing what I learned to one of my sci-
ence courses. But I still had some con-
cerns. What would it look like when
implemented? Would there be time to
include a cultural focus in addition to
the science content? Would the cultur-
al focus distract from the science con-
tent? How would students respond?
In this article, we describe a two-part
lesson in which I employed socially
transformative science curriculum as
one means of being culturally respon-
sive. I also conclude with some of the
benets realized from the experience.
What is socially
transformative science
curriculum?
The goal of socially transformative
curriculum is to help children devel-
op the tools they need to “transform”
the society in which they live (Freire
1970; Pitts Bannister et al. 2017). I es-
pecially like this goal for the students
that I teach because many hope to one
day change their social circumstances.
Many opportunities exist in the tradi-
tional science curriculum for teachers
to help prepare science learners for
the long-term goal of social change.
To provide some guidance, there
are ve areas of mastery that we want
to help students to achieve (Mutegi
2011). First, students should develop a
mastery of content. The bulk of our in-
structional focus is aimed at helping
students to understand content, and
January/February 2021 45
to represent atoms, molecules, and compounds. Both
modications are consistent with Mutegi’s (2011) de-
scription of socially transformative STEM curriculum,
as well as the Next Generation Science Standards’ (NGSS
Lead States 2013) emphasis on foregrounding culture
(National Research Council 2012, pp. 306–307) and
critiquing (National Research Council 2012, p. 77) and
identifying limitations of models (National Research
Council 2012, pp. 56–58).
Engagement (10 minutes)
This is the rst lesson in the chemistry unit. Typical-
ly, students are familiar with the Bohr model of the
atom. Students also come with the idea that atoms
are small and that they make up matter. By contrast,
they do not typically have an idea of the various vi-
sual models used to represent molecules. They are
largely unfamiliar with ball-and-stick models for
molecules and compounds. For many, it is their rst
opportunity to create and manipulate these models.
To begin the engagement, I project an image of the
three-dimensional model for a melanin molecule on
the screen. This image is also provided on the rst
page of the students’ journal entry with the caption,
“What do you think this is?” Students are instructed
to write a description of what they see in their jour-
nals. An example of a student’s journal entry is shown
in Figure 1. The image I use for the melanin molecule
is taken from PubChem (see Resources). Once stu-
dents complete the rst part of the journal entry, I re-
veal that they are looking at the compound melanin.
I then use open-ended questions to engage the class
in a discussion of the biological role of melanin: Has
anyone heard of melanin? What does melanin do?
Why is melanin important? What are the properties of
melanin? During the discussion, students take notes
on melanin in their journals.
In guiding the discussion, there a few points I un-
derscore. On the biological role of melanin, I make
sure to emphasize that (a) melanin is a pigment found
in nature; (b) in humans melanin is reected in skin,
hair, and eye color; (c) nonhuman mammals and some
plants also have melanin; and (d) greater amounts
of melanin are responsible for darker colors. On the
chemical classication of melanin, I make sure to
emphasize that (a) melanin is a compound; (b) com-
pounds are made of two or more different elements;
and (c) the elements seen in our melanin compound
are carbon, hydrogen, nitrogen, and oxygen. On the
importance or benets of melanin, I make sure to em-
phasize that (a) melanin is essential to brain, nerve,
and organ function; (b) it provides protection against
ultraviolet radiation; and (c) it promotes younger
looking skin in humans.
This engagement could be conducted with any
number of compounds. I considered both glucose (the
simplest monosaccharide and a key component of
many carbohydrates) and capsaicin (one of the mole-
cules that make peppers hot). However, I use melanin
because it provides an opportunity to help students
develop an understanding of how the content relates
to them as people of African descent (context).
| FIGURE 1: Student journal entry for
engagement exercise.
46
Exploration (30 minutes)
For the exploration portion of the
lesson, I provide students with
red, yellow, and blue modeling
clay; toothpicks; trays; and a list
of ve chemical formulas (C,
H2O, H2, CO, and CO2). Working
in groups of three, their rst task
is to form the clay into balls, each
ball representing an atom. Each
color represents either carbon,
hydrogen, or oxygen. Using the
clay and toothpicks, students
create models reecting each
of the formulas provided. They
also indicate whether each is an
atom, molecule, or compound.
After creating their models,
students collaborate with their
groupmates to create graphic or-
ganizers representing the ve chemical formulas. Each
group is expected to explain to the class the rationale
behind the organization used.
Explanation (20 minutes)
The explanation portion of the lesson is aimed at fa-
cilitating students’ understandings of the differences
between atoms, molecules, and compounds. To be-
gin this portion of the lesson, students are provided
with a Venn diagram featuring bubbles for molecules,
compounds, and atoms as well as brief descriptions of
each (see Figure 2). A version of this diagram is pro-
jected for the whole class to see. I then lead the class
in a discussion during which we write the chemical
formulas on the diagram to indicate where each of the
ve models should be placed. After adding our ve
formulas to the diagram, I provide students with six
new formulas (NaCl, Ag, Co, SO2, H2, and C18H10N2O2).
Working in their groups, students decide where these
formulae should be placed on the Venn diagram.
Elaboration (20 minutes)
At this point in the class, I have provided students
with 11 chemical formulas. For the elaboration
portion of the lesson, I ask students to identify the
common or scientic names for as many of these
formulae as possible. I then ask students to record
answers to two questions in their journals. The rst
question asks, “How are the clay models similar to
(and different from) actual atoms, molecules or com-
pounds?” The second question asks, “What are the
advantages and disadvantages of using clay models
to represent atoms, molecules, or compounds?” This
portion of the lesson concludes with a discussion of
the strengths and weaknesses of scientic models.
Typically, the types of disadvantages students pin-
point are inaccuracies in the scale of our models (e.g.,
“in our models the distance between atoms is xed”
or “our models do not represent the relative sizes of
atoms”) and the incompleteness of our models (e.g.,
“our models do not show different types of bonds” or
“our models do not show components of atoms”). I
draw from their comments to help them see that they
are identifying inaccuracies in scale or incomplete-
ness in models. These larger themes are revisited
throughout the course when examining other scien-
tic models.
These questions and the related discussion pro-
vide a good opportunity to support students’ efforts
| FIGURE 2: Venn diagram for molecules, compounds, and atoms.
January/February 2021 47
THE MOLECULES THAT MAKE ME UNIQUE
to become more critical consumers and producers
of scientic knowledge (critique). Because students
are readily able to see limitations in their own rep-
resentations (models), I use this as a starting point
for helping them to see limitations in scientic rep-
resentations (models). The models that scientists use
to represent the world are always incomplete. They
are tentative. They are not fully accurate. They leave
a lot unanswered. While these characteristics do not
invalidate scientic models, they do encourage us to
be measured when we think about how fully a mod-
el represents the natural world.
Evaluation (15 minutes)
Although students participate in a number of forma-
tive assessments throughout this lesson (e.g., small-
and whole-class discussion), the journal entry and
the Daily Science Review (see Online Supplemental
Resources) are the culminating evaluation activities.
For their nal journal entries, students rst complete
a table wherein they identify a substance, its chemical
formula, its classication (i.e., element, molecule, or
compound), and a two-dimensional model of the
classication. Following that, they summarize their
understanding of the limitations of models. Figure 3
| FIGURE 3: Exit assessment: Formula,
classification, and model.
Students modeling molecules.
Photo courtesy of Vanessa Gee
48
Jomo W. Mutegi (jmutegi@iupui.edu) is an associate professor in the Urban Teacher Education Department at Indiana
University Purdue University at Indianapolis. Vanessa Gee is a doctoral student in the Urban Education Studies program at
Indiana University Purdue University at Indianapolis and a science teacher in the Metropolitan School District of Washington
Township in Indianapolis, Indiana.
provides a student’s example of this nal journal
entry.
In their journals, students frequently pointed out
that they heard about melanin before. It is a term
that is frequently used in popular culture. They have
heard and seen phrases such as “Your melanin is
poppin” or #MelaninMagic. They were, however,
unfamiliar with the chemical properties of melanin
or the fact that melanin is found in plants and in non-
human animals.
After the journaling, students completed a Daily
Science Review, which is a ve-question, multiple-
choice assessment aimed at determining the degree
to which students were able to differentiate between
atoms, elements, molecules, and compounds. I use
it to determine whether (and how much) I need to
revisit the topics covered. The students did particu-
larly well on the question assessing understanding
of compounds, and the overall scores were notably
higher than is typical of Daily Science Reviews.
Subsequent lessons build from this introductory
lesson in two ways. First, students extend their knowl-
edge of molecular modeling to describe and explain
particle motion, density, temperature, and changes in
states of matter as a function of adding or removing
thermal energy. Second, students are presented with
more complex molecules and compounds, as well as
alternative ways to represent them.
Summary
The lesson implementation described here provides
an example of how a socially transformative approach
to science curriculum can be readily implemented in
a traditional science classroom. The description also
shows that subtle, yet powerful modications proved
benecial to both my students and to me. The rst
readily identiable benet for my students was in-
creased engagement. Students asked more questions,
contributed more thoughtful input, and were more
condent in themselves throughout the lesson. It was
extended throughout the lesson and was evidenced
in journal entries that (a) were more extensive, and (b)
made more personal connections. A second benet for
my students was increased assertiveness. While stu-
dents were more condent than normal throughout
the lesson, when they were called on to critique the
veracity of their models and of scientic models in
general, they embraced that opportunity and asserted
their ideas with vigor.
The modications made using the socially trans-
formative approach allowed me to include African
Americans in my science curriculum and to be able
to underscore something culturally afrming in do-
ing so.
REFERENCES
Freire, P. 1970. Pedagogy of the oppressed. New York, NY:
Herder & Herder.
Mutegi, J.W. 2011. The inadequacies of “science for all” and
the necessity and nature of a socially transformative
curriculum approach for African American science
education. Journal of Research in Science Teaching 48:
301–316. doi: https://doi.org/10.1002/tea.20410
National Research Council. 2012. A framework for K-12 science
education: Practices, crosscutting concepts, and core
ideas. Washington, DC: The National Academies Press.
NGSS Lead States. 2013. Next Generation Science Standards:
For states, by states. Washington, DC: National Academies
Press. www.nextgenscience.org/next-generation-science-
standards.
Pitts Bannister, V. R., J. Davis, J.W. Mutegi, L.R. Thompson, and
D.D. Lewis. 2017. “Returning to the root” of the problem:
Improving the social condition of African Americans
through science and mathematics education. Catalyst: A
Social Justice Forum 7 (1): 4–14.
RESOURCES
PubChem—https://pubchem.ncbi.nlm.nih.gov/
ONLINE SUPPLEMENTAL RESOURCES
Daily Science Review—https://www.nsta.org/online-
connections-science-scope
January/February 2021 49
THE MOLECULES THAT MAKE ME UNIQUE
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Article
The underachievement and underrepresentation of African Americans in STEM (Science, Technology, Engineering and Mathematics) disciplines have been well documented. Efforts to improve the STEM education of African Americans continue to focus on relationships between teaching and learning and factors such as culture, race, power, class, learning preferences, cultural styles and language. Although this body of literature is deemed valuable, it fails to help STEM teacher educators and teachers critically assess other important factors such as pedagogy and curriculum. In this article, the authors argue that both pedagogy and curriculum should be centered on the social condition of African Americans – thus promoting mathematics learning and teaching that aim to improve African communities worldwide.
Article
“Science for All” is a mantra that has guided science education reform and practice for the past 20 years or so. Unfortunately, after 20 years of “Science for All” guided policy, research, professional development, and curricula African Americans continue to participate in the scientific enterprise in numbers that are staggeringly low. What is more, if current reform efforts were to realize the goal of “Science for All,” it remains uncertain that African American students would be well-served. This article challenges the idea that the type of science education advocated under the “Science for All” movement is good for African American students. It argues that African American students are uniquely situated historically and socially and would benefit greatly from a socially transformative approach to science education curricula designed to help them meet their unique sociohistorical needs. The article compares the curriculum approach presented by current reform against a socially transformative curriculum approach. It concludes with a description of research that could support the curricular approach advocated. © 2011 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 301–316, 2011
A framework for K-12 science education: Practices, crosscutting concepts, and core ideas
National Research Council. 2012. A framework for K-12 science education: Practices, crosscutting concepts, and core ideas. Washington, DC: The National Academies Press. NGSS Lead States. 2013. Next Generation Science Standards: For states, by states. Washington, DC: National Academies Press. www.nextgenscience.org/next-generation-sciencestandards.