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Rat High Fructose Corn study- Jenny Green

   
  Rat at the end of the study- notice the large stomach!

Research Question and Hypothesis

Does High Fructose Corn Syrup cause more weight gain than Sucrose (table sugar)?
Standards
Biology:
Cell Biology

 1.The fundamental life processes of plants and animals depend on a variety of chemi­ cal reactions that occur in specialized areas of
                the organism’s cells. As a basis for understanding this concept:                                                                                                                               a.Students know cells are enclosed within semipermeable membranes that regulate their interaction with their surroundings.
 b.Students know enzymes are proteins that catalyze biochemical reactions without altering the reaction equilibrium and the                 activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings.

 e.Students know the role of the endoplasmic reticulum and Golgi apparatus in the secretion of proteins.

 g. Students know the role of the mitochondria in making stored chemical-bond energy available to cells by completing the breakdown of glucose to carbon dioxide.

 h.Students know most macromolecules (polysaccharides, nucleic acids, proteins, lipids) in cells and organisms are synthesized from a small collection of simple precursors.

i.* Students know how chemiosmotic gradients in the mitochondria and chloroplast store energy for ATP production.

            

Physiology


9.As a result of the coordinated structures and functions of organ systems, the internal environment of the human body remains relatively stable (homeostatic) despite changes in the outside environment. As a basis for understanding this concept:

 a.Students know how the complementary activity of major body systems provides cells with oxygen and nutrients and                 removes toxic waste products such as carbon dioxide.

 c.Students know how feedback loops in the nervous and endocrine systems regulate conditions in the body.

 f.*Students know the individual functions and sites of secretion of digestive enzymes (amylases, proteases, nucleases, lipases),                          stomach acid, and bile salts.

 g.* Students know the homeostatic role of the kidneys in the removal of nitrogenous wastes and the role of the liver in blood detoxification and glucose balance.

 i.*Students know how hormones (including digestive, reproductive, osmoregula­ tory) provide internal feedback mechanisms for homeostasis at the cellular level and in whole organisms.


Investigation and Experimentation


1. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other four strands, students should develop their own questions and perform investigations. Students will:

a. Select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data.

b.Identify and communicate sources of unavoidable experimental error.

c.Identify possible reasons for inconsistent results, such as sources of error or uncontrolled conditions.

d.Formulate explanations by using logic and evidence.

j.Recognize the issues of statistical variability and the need for controlled tests.

k.Recognize the cumulative nature of scientific evidence.

l.Analyze situations and solve problems that require combining and applying concepts from more than one area of science.

m. Investigate a science-based societal issue by researching the literature, analyzing data, and communicating the findings. Examples of issues include irradiation of food, cloning of animals by somatic cell nuclear transfer, choice of energy sources, and land and water use decisions in California.

n.Know that when an observation does not agree with an accepted scientific theory, the observation is sometimes mistaken or fraudulent (e.g., the Piltdown Man fossil or unidentified flying objects) and that the theory is sometimes wrong (e.g., the Ptolemaic model of the movement of the Sun, Moon, and planets).

Experimental Design

Students have three groups of rats, 14 in the HFCS, 14 in Sugar, 14 in Water group.  Rats are fed lab food (Kaytee brand), as much as they want.  HFCS mixed with water in water bottles at 10% solution. High fructose corn syrup is found in the form of Mrs. Butterworth's Pancake syrup, CH brand table sugar mixed with tap water to create a 10% solution.  Sugars were mixed and placed in the rats water bottles.  .  Rats are massed twice weekly and bedding is changed once weekly.  Experiment lasts 3 months.
Independent variable
Time measured over 3 months time

Dependent variable

Mass of Rats- series is 7 groups of HFCS, 7 groups of sugar, 7 groups of Water.

Constants and Controls

Constant factors: percent of sugar, hfcs, water given each week, type of rat chow, bedding used, types of cages used, types and ages of rats used, male and females used, types of sugar, HFCS and water same each time, mass taken same days of the week for 3 months.

Control group: Water- feed tap water in water bottles as opposed to sugar infused water

Materials:

norweigian lab rats- rat breeder (4 wks old) - 40 total rats- 20 males, 20 females (We chose to use both sexes in order to possibly observe changes between the genders.)

30 water bottles with rubber stoppers

30 cages- (males need to be separated) 

10 bags of sani-chip bedding

60 lbs of rat chow KayTee Rat food (Petco or Petsmart)

50 lbs of table sugar

12 bottles of HFCS Mrs. Butterworth's Pancake syrup bottles (32 oz)

tap water

cage cards and notebooks for recording 

400 gram electronic scales

Rat cage, water bottle and set up
Sucrose group
High Fructose Source
Rat chow

Sani-chips



Procedures

A. Students develop hypothesis for each group of rats.
B. Student read the study Princeton released to study how they set up their lab.
C. Students read opposing view points of Princeton study.
D. Student plan out study including what controls might be needed, data tables created, procedures written out.

Students developed the following procedures:

1. Record the characteristics of each rat assigned to each student.  Recommended to take permanent maker and make mark on tails to distinguish between the rats and also take pictures.  Then set up cages and take initial mass of rats.  After recording mass, create cage cards identifying which group the rats are being tested for, as well as student's names.  Make sure to separate males because of fighting.  Males can be placed in separate cages and females may be placed two to a cage.

2. Record mass of each rat twice weekly.

3. Check rats daily for food and water rationing.  

4. Change bedding twice weekly, using sani-chips.

Sample data and graphs

Rat data weekly % mass rats for each group

Rat Data sheets % change for each mini group


Chart 1



weekly mass ‎(grams)‎totals for rats for each group


Analysis & Conclusions

You can see overall that the High Fructose Corn Syrup actually had the greatest gain but not by much over the water group.  One of the issues we had was two different age groups on the rats.  One group was recieved from a University at about 4 months old and another was purchased from a breeder at about 2 months old.  The growth rate interfered with the actual percent change in the sugar weight gain. Plus we had lots of students which would lead to many errors in such things as massing and measuring of sugars.  This lab was a great experience for the kids and they really enjoyed the responsibility of taking care of the rats as well as setting up an experiment based on a real live study.   Below was the flow chart for topics leading up to and supporting the study.

ap agenda inquiry for rats.doc

HFCS study initial study questions.doc




Photos & Movies




References
HFCS Scientific Review- refutes connection between HFCS and weight gain
HFCS and memory loss- scientific american article



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Jennifer Green,
Nov 16, 2011, 9:23 PM
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