Ideal Diet for a Cell

Audrey DeZeeuw, Julia Neumann, & Jennifer Gidley

Introduction

Anchor Video

Intro Paper

Project Description

Through a six week unit focusing on nutrition, students will learn to make better health choices and become better consumers. Incorporating relevant benchmark lessons, this unit will challenge students to design and implement a diet for mealworms. The students will learn about important components to nutrition and will see the effects of their choices on the mealworms. Using scientific analysis, the students will analyze and discuss the results of the chosen nutritional plans and apply it to human consumption. As the students continue their research, they will be exposed to mechanisms of cellular metabolism; they will be able to observe other animals feeding; they will gain an insight on the responsibilities of a registered dietician; and, they will engage in classroom discussions on current diet trends. The unit will culminate in a series of presentations open to parents and other community members to help increase awareness about nutrition and help others learn to make better nutritional choices.

Driving Challenge

Design the ideal diet for a particular cell.

Overall Goals of the Project

The specific goals of the project include: having students design and implement a diet for meal worms based on researching cellular and organ needs; having students consider the impact of nutrition on physiology; having students evaluate the validity of claims made by various popular diets; producing more active consumers; and engaging students in science. At the end of the project, students will pass on their scientific findings to parents, teachers, and other interested students in presentations that will include aspects of the project from procedure to results. These presentations will increase the number of people impacted by spreading the concepts learned throughout the community.

Rationale

Turn on your TV, drive a few blocks, listen to the radio, and walk into just about any restaurant, and you're sure to encounter some form of commercialization for dieting. Atkin's, South Beach, diet pills, and weight-loss programs are diet trends that are common in the American market. With the prevalence in today's media and the focus on body images, students of any school are affected by the hype driven by media around these products and trends. This is reflected by an increase in eating disorders, particularly in girls of high school age. According to the Diagnostic and Statistic Manual of Mental Disorders , around 3% of the female students are affected by an eating disorder.

The project is intended to provoke students to question fad diets. They will discover the biological mechanisms behind dieting by implementing a diet of their own design on mealworms. The students will monitor the mealworms as they progress through the unit to evaluate the effects of the diet they designed. With help from registered dietician Elizabeth Wilkes, the students will apply the knowledge gained from the mealworm model and draw a parallel to human dietary needs. By gaining a better understanding of nutrition and the physiological effects of nutrition, the students will be able make more informed choices as consumers. They will question the veracity of advertisements and claims made by manufacturers and promote healthy choices to the community in a culmination presentation.

Background Information

Cell and their processes: information available at www.cellsalive.com

Mealworms: Mealworms are the larval form a common beetle known as the Darkling beetle. The larval stage is just one in the entire process of metamorphosis the beetle goes through, from egg to larva to pupa to beetle. The larval stage is ideal to study because it lasts for a period of three weeks in which the beetle continually molts until it forms a pupa.

To care for the mealworm a shallow container with an aerated lid will suffice for the organisms housing. Common foods for the mealworm include apples or bran flakes. A potato is also necessary in the mealworm house as a source of moisture for the animal. Care should be taken when using the potato as it can mold easily and provide too much dampness that would kill the mealworm. These scarce conditions are not only enough to support the larval stage of the beetles' metamorphosis, they can support the pupa and beetle stages as well! It is quite simple to create your own mealworm colony by simply providing them with the aforementioned food and housing.

Nutrition and Fad Diets: It is through the consumption of food that we obtain our nutrition and energy. Some of the primary components in our food that assist in our survival include the usual vitamins and minerals, water, carbohydrates, enzymes, fats, protein, and fiber. Together these components provide us with energy, proper metabolic functioning, prevention of diseases and disorders and much more. The only way to obtain all these components and thus live a healthy lifestyle is through eating a varied diet.

The cornerstone of the Atkins philosophy is a four-phase eating plan in conjunction with vitamin and mineral supplementation and regular exercise. Further, it is based upon four principles. The phases in the Atkins roadmap to sustained success are:

Phase 1: Induction: Restrict carbohydrate consumption to 20 grams each day, obtaining carbohydrate primarily from salad and other non-starchy vegetables.

Phase 2: Ongoing Weight Loss (OWL): Add carbohydrate, in the form of nutrient-dense and fiber -rich foods, by increasing to 25 grams daily the first week, 30 grams daily the next week and so on until weight loss stops. Then subtract 5 grams of carbohydrate from your daily intake so that you continue sustained, moderate weight loss.

Phase 3: Pre-Maintenance: Make the transition from weight loss to weight maintenance by increasing the daily carbohydrate intake in 10-gram increments each week so long as very gradual weight loss is maintained.

Phase 4: Lifetime Maintenance: Select from a wide variety of foods while controlling carbohydrate intake to ensure weight maintenance and a sense of well-being. This lifestyle is the foundation for a lifetime of better health.

The most drastic way to reduce caloric intake is to stop eating completely. After a few days, body fats and proteins are metabolized to produce energy. The fats are broken down into fatty acids that can be used as fuel. In the absence of adequate carbohydrate, the fatty acids may be incompletely metabolized, yielding ketone bodies and thus ketosis. Prolonged fasting is unsafe, because it causes the body to begin to digest proteins from its muscles, heart, and other internal organs.

Low-carbohydrate diets also produce ketosis. As it begins, large amounts of water will be shed, leading the dieter to think that significant weight reduction is taking place. However, most of the loss is water rather than fat; the lost water is regained quickly when eating is resumed. Appetite, often reduced during ketosis, also returns when a balanced diet is resumed.

Most low-carbohydrate diets do not attempt to limit the intake of proteins, fats, or total calories. (In other words, their fat content tends to be very high.) Promoters claim that unbalancing the diet will lead to increased metabolism of unwanted fat even if the calories are not restricted. This is not true, but calorie reduction is likely to occur because the diet's monotony tends to discourage overeating.

The nutrition committee of the American Heart Association has issued a science advisory warning that high-protein diets have not been proven effective and pose health risks. The report covered the Atkins, Zone, Protein Power, Sugar Busters, and Stillman diets. The committee stated:

Such diets may produce short-term weight loss through dehydration.
Weight loss may also occur through caloric restriction resulting from the fact that the diets are relatively unpalatable.
The high fat content may be harmful to the cardiovascular system in the long run.
Any improvement in blood cholesterol levels and insulin management would be due to weight loss, not the change in composition.
A very high-protein diet is especially risky for patients with diabetes because it can speed the progression of diabetic kidney disease.
A high intake of saturated fats over time raises great concern about increased cardiovascular risk. The study did not follow participants long enough to evaluate this.

THE DIETARY GUIDELINES FOR AMERICANS

Eat a variety of foods to get the energy, protein, vitamins, minerals, and fiber you need for good health.

Balance the food you eat with physical activity - maintain or improve your weight to reduce you chances of having high blood pressure, heart disease, a stroke, certain cancers, and the most common kind of diabetes.

Choose a diet with plenty of grain products, vegetables, and fruits which provide needed vitamins, minerals, fiber, and complex carbohydrates, and can help you lower your intake of fat.

Choose a diet low in fat, saturated fat, and cholesterol to reduce your risk of heart attack and certain types of cancer and to help you maintain a healthy weight.

Choose a diet moderate in sugars. A diet with lots of sugars has too many calories and too few nutrients for most people and can contribute to tooth decay.

Choose a diet moderate in salt and sodium to help reduce your risk of high blood pressure.

If you drink alcoholic beverages, do so in moderation. Alcoholic beverages supply calories, but little or no nutrients. drinking alcohol is also the cause of many health problems and accidents and can lead to addiction

Chart for vitamins and their functions: www.petdoc.ws/PsitDiet.html

Standards Addressed

TEKS for our project

(1) In Biology, students conduct field and laboratory investigations, use scientific methods during investigations, and make informed decisions using critical-thinking and scientific problem-solving. Students in Biology study a variety of topics that include: structures and functions of cells and viruses; growth and development of organisms; cells, tissues, and organs; nucleic acids and genetics; biological evolution; taxonomy; metabolism and energy transfers in living organisms; living systems; homeostasis; ecosystems; and plants and the environment.

(2) Science is a way of learning about the natural world. Students should know how science has built a vast body of changing and increasing knowledge described by physical, mathematical, and conceptual models, and also should know that science may not answer all questions.

(3) A system is a collection of cycles, structures, and processes that interact. Students should understand a whole in terms of its components and how these components relate to each other and to the whole. All systems have basic properties that can be described in terms of space, time, energy, and matter. Change and constancy occur in systems and can be observed and measured as patterns. These patterns help to predict what will happen next and can change over time.

(4) Investigations are used to learn about the natural world. Students should understand that certain types of questions can be answered by investigations, and that methods, models, and conclusions built from these investigations change as new observations are made. Models of objects and events are tools for understanding the natural world and can show how systems work. They have limitations and based on new discoveries are constantly being modified to more closely reflect the natural world.

>(1) Scientific processes. The student, for at least 40% of instructional time, conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to:

(A) demonstrate safe practices during field and laboratory investigations; and

>(2) Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is expected to:

(A) plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology;

(B) collect data and make measurements with precision;

(D) communicate valid conclusions.

3) Scientific processes. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to:

(A) analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information;

(B) evaluate promotional claims that relate to biological issues such as product labeling and advertisements;

(4) Science concepts. The student knows that cells are the basic structures of all living things and have specialized parts that perform specific functions, and that viruses are different from cells and have different properties and functions. The student is expected to:

B) investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules;

(10) Science concepts. The student knows that, at all levels of nature, living systems are found within other living systems, each with its own boundary and limits. The student is expected to:

(A) interpret the functions of systems in organisms including circulatory, digestive, nervous, endocrine, reproductive, integumentary, skeletal, respiratory, muscular, excretory, and immune;

(B) compare the interrelationships of organ systems to each other and to the body as a whole; and

(9) Science concepts. The student knows metabolic processes and energy transfers that occur in living organisms. The student is expected to:

(A) compare the structures and functions of different types of biomolecules such as carbohydrates, lipids, proteins, and nucleic acids;

(B) compare the energy flow in photosynthesis to the energy flow in cellular respiration;

(D) analyze the flow of matter and energy through different trophic levels and between organisms and the physical environment

11) Science concepts. The student knows that organisms maintain homeostasis. The student is expected to:

C) analyze the importance of nutrition, environmental conditions, and physical exercise on health;

Description of formative and summative assessments

Projective prospectus, classroom opinion poll-This assessment could be used when discussing diets, to see how students really think about the new trends and see how the debate has impacted their opinions.
The interest knowledge skills checklistcould be use to assess students' level of interest in topics the unit will cover prior to starting the unit. The use of this would be to emphasize the parts of the unit students are most interested in, and de-emphasize those that the students have the most experience in, or take those on a more in depth level, so as to avoid student boredom. The more interested students are, the more they will learn and pay attention, which would increase the success of the project.
The diagnostic learning logs would be great for students ready to analyze their own skills as learners. Students would keep a log through the entire project, to give themselves and the teacher feedback to improve lessons and make sure students understand material. By keeping a journal throughout the six weeks (or semester) students will be more aware of their own strengths and weaknesses so they can properly prepare for tests and not fall behind.
The Problem Recognition Task could be incorporated into the unit when considering the consequences of certain diet deficiencies. Students would be presented with symptoms and, using their new knowledge of diet/nutrition information, they could come up with possible causes of the symptoms to diagnose.
The one-sentence summary technique would be a good way for students to synthesize their knowledge of processes such as respiration and photosynthesis, which are both included in our unit. They would have to use one sentence to link all of the steps, which would give them a cohesive overview of a more complex topic. I think it would help them recall the overall ideas of each in the future.
The "pro and con" grid would fit perfectly into the debate section of our unit that has students look at diets that have been designed and debate on whether they would work and be healthy. In a pro and con grid, students would be able to get their ideas down in an organized system. This will help them to learn how to evaluate issues in other realms as well by sitting down and logically thinking about the ramifications of such issues by considering both positive and negative aspects. It is a skill critical to functioning in a social context, so students can carry this into the world and be able to make more informed choices.
memory matrix assessment technique would be another good way to start off the 6 weeks to recap the cell structures that students have already learned and to build on with the cell membrane, which is a new topic. Each organelle would have its own line, with "structure" and "function" being two headings to fill in for each organelle. The students would fill the chart in as best they can, and then whatever they are not clear on can be recovered as needed for the cell nutrition unit. They could then take the chart and build on it with the membrane and larger organs that fit into the nutrition unit.

Project Grading Rubric

Background Research (due at end of week 1):

presented in APA format with correct grammar
sufficient to make informed choices, including (but not limited to):
meal worm dietary needs
meal worm anatomy

10 points possible

Project Design Plan (due at end of week 2)

Procedure
Materials
Hypothesis
Potential methods of data collections and analysis
Proposed diet (based on research)

20 points possible

Project Implementation (done in shifts by group; each group does this for 1 week)

Group diet selection
Data collection
Feeding worms
Participation

10 points possible

Data and Analysis

Log books complete
Statistical analysis of data; are the worms in each group really different?

20 points possible

Conclusion

Synthesis of results; back your conclusion with the data you've collected
Include any confounding variables

10 points possible

Presentation

Content: cover all pertinent material (procedure ˆ conclusion)
Clarity (target towards someone with no biology background)
Communication Style (use whatever format you think best fits!)

30 points possible