Understanding Kidney Disease
Roots Charter School, Brooklyn
Program for Science Teachers
3rd to 5th
can the scientific method be used to understand kidney disease?
- understand the
function of our kidneys
- identify basic
parts of the urinary system
organ, kidney, nephrons, waste, blood, vitamins, minerals, urinary system,
bladder, ureters, scientific method, hypothesis, data, observations, procedure,
results, conclusions, mass, circumference
salt, sugar, water, vegetable oil, clear cups, permanent markers, graduated
cylinders, measuring tape, spoons, balance, sponges, paper towels,
What are the
essential things that humans need in order to survive? [make list on board:
air, water, food, shelter]. Of the ones that are on the board, which one(s)
have to do with what is going on within our body? [air, water, food]. So
what happens to those 3 items once they go into our bodies? [Eventually
something comes out like CO2 or waste/urine. We have specific organs in our
body that are like little machines that have very specific jobs. One of the
most important organs is one that people often overlook: our kidneys. Show a
diagram of the kidneys and how they are a part of the urinary system.]
Looking at the diagram, why do you think our urinary system, including our
kidneys are so important?
they help to remove waste in the blood. What kind of waste? Well, think
about what kinds of foods we eat – how do they taste? [sweet, salty, greasy,
Now that you know a little bit about our kidneys, let’s try to use our
knowledge of the scientific method to figure out a question: What kinds of
waste do our kidneys interact with?
How are we going to
solve this problem?
Each group will get 4
“kidneys”, which are raw eggs. Each group will also need 4 clear cups, 1
permanent marker, 1 spoon, 1 marked cup with granulated sugar with a spoon,
1 marked cup with table salt with a spoon, 1 marked cup with vegetable oil
with spoon, and a pitcher of water. Ask students how we can use these
materials to figure out if it is sugar or salt that is being removed from
our blood by our kidneys.
Once a procedure is established and written on the board, have groups begin
setting up their experiment. Be sure to test before hand to make sure that
students add enough sugar/salt to the point of saturation in the water.
4 cups labeled:
water, salt, sugar, vegetable oil
amount of water from pitcher in graduated cylinder and pour carefully
into the 3 cups so that all cups have the identical amount. Be sure that
the amount of water determined leaves enough room to add sugar/salt and
Add the determined
amount of salt into the salt cup with water and stir until completely
dissolved. Add the determined amount of sugar into the sugar cup with
water and stir until completely dissolved.
Label each egg with
a 1, 2, 3 or 4. Measure the eggs’ mass and circumference around the
Place each egg into
the designated cup. Record observations.
Let it sit over
hypothesize what you think will happen and write it down.
Clean up and wrap up
with students for the day’s activity. Share hypotheses and reasoning.
When students return the
following day, have students review the urinary tract and revisit their
hypothesis. In their groups, first observe their cups and record any changes
that the see. After recording, hand out paper towels, balances, and
measuring tapes. Gently wipe off each egg at a time, make any kind of
observations, then measure the mass and circumference of each one. Record.
Analyze the data:
Finish the data table. Show students how to fill out the graph using their
data table, colored pencils, and ruler. Once students’ graphs are completed,
have their groups come up with a sentence for each sample as to what
happened, and a sentence or two describing if and how their experiment could
lead to any kind of conclusion about the question posed.
take one group’s egg in water sample. Cover the egg in vinegar to dissolve
the shell. Remove and then carefully pierce the membrane with a needle
jet of water will shoot out. Ask students why this happened. Does this help
to explain some of the results in your table?
Review and Explanations:
go over what
students observed as a class. Explain that the changes in the egg that they
observed and recorded show that those substances are ones that can affect
our own kidneys.
the kidneys did not remove them, these wastes would build up in the blood
and damage the body. The actual removal of wastes occurs in tiny units
inside the kidneys called nephrons. Each kidney has about a million nephrons.
Most kidney diseases attack the nephrons, causing them to lose their
How do you think we can take care of our kidneys?
New York State Standards:
Inquiry, and Design
Critical thinking skills are used in the solution of mathematical problems.
Use appropriate scientific tools, such as metric rulers, balance, graph paper,
cylinder to solve problems about the natural world.
T1.3 Generate ideas for possible solutions, individually and through
group activity; apply age-appropriate mathematics and science skills; evaluate
the ideas and
determine the best solution; and explain reasons for the choices.
Standard 6: -
Equilibirum and Stability
are simplified representations of objects, structures, or systems used in
analysis, explanation, interpretation, or design
Standard 7: -
knowledge and skills of mathematics, science, and technology are used together
to make informed decisions and solve problems, especially those relating
to issues of science/technology/society, consumer decision making, design, and
inquiry into phenomena.
science/technology/society problems and issues that affect their home,
school, or community, and carry out a remedial course of action