Download Polymer Lesson - Penn Arts and Sciences

Patty McCarrin
Cory Redding
Biology Lesson
July 20, 2004
Audience- Cory Redding
Eighth Grade Physical Science- William Allen Middle School, Moorestown, New Jersey
There are approximately 24 eighth grade students in each of my five eighth grade physical
science classes. The classes meet for 45 minutes daily. Students are not tracked by academic
ability, but instead grouped heterogeneously. One of the five classes is an inclusion class in which
there are special education students mainstreamed with regular education students. The special
education students range from auditory impaired to attention deficit disorder. There is a support
teacher in that class who modifies tests and provides the students who have IEPs specifically for
science with additional support. There is also an interpreter who signs for four auditory impaired
students.
The environment of each of the classes is one of excitement, energy and positive attitudes.
Each of the five classes learns the same subject matter. The students are on task and focused for the
majority of the class period. They enjoy coming to science class and are most eager to learn when a
hands-on activity is taking place. Students are often required to relate their findings to the real
world, and specifically their lives. They are enthusiastic about discussing topics that they can
connect with.
Students are often asked to think critically and apply higher order thinking skills. It is
frequently required that students explain why scientific phenomena occur. Seldom are students
asked to memorize facts but instead they must apply scientific concepts to prove mastery of content.
Student expectations range from designing and implementing their own experiments using the
scientific method to conducting teacher designed guided activities to participating in a classroom
discussion. A driving, or essential, question is presented to the students at the beginning of the
investigation and the teacher refers back to that question throughout the related activities. An
evaluation may simply be to answer, in detail, the driving question at the end of the lesson.
Identify an area of biology that you know is frequently difficult for students
The function of biological polymers is affected by its make up.
Enduring Understanding
We can understand biological phenomena by analyzing them at multiple levels from the
molecular to the organism level.
Standards:
Content Standard A
• Use appropriate tools and techniques to gather, analyze and interpret data.
• Develop descriptions, explanations, predictions and models using evidence.
• Think critically and logically to make the relationships between evidence and
explanations.
Content Standard B
• Students observe and measure characteristic properties and use those properties to
distinguish and separate one substance from another.
Content Standard C
• Living Systems at all levels of organization demonstrate the complementary nature of
structure and function.
• Disease is a breakdown in structures or functions of an organism. Some diseases are
the result of intrinsic failures of the system.
Background Content and Discussion of Pedagogic Literature
Biologic Polymers Teacher Background Information
Polymers are made up of monomers. The three main types of biologic polymers are proteins,
polysaccharides and nucleic acids. Lipids are not considered polymers because they are not
composed of component part molecules (Krough, 2005).
Proteins
Proteins accomplish a multitude of functions within the body and are often referred to as
building-block molecules. They are made up of monomers called amino acid joined together by
polypeptide bonds. Amino acids have a typical structure, consisting of a carbon atom in the middle
with an amino group on one side, a carboxyl group on the other and a hydrogen atom attached to the
“top.” What differentiates one amino acid from the other is the side-chain, or “R” group. The
variation in the R position results in twenty different amino acids.
www.hcc.mnscu.edu/.../ amino_acid_structure_2.jpg
Whilst the protein is forming and monomers are lined up in a chain, the correct terminology is a
polypeptide. Once the polypeptide is folded, it is considered a protein. Below is a diagram of how
a protein is synthesized.
www.accessexcellence.org/ RC/VL/GG/images/protein.jpg
The shape of the protein is imperative to its function. Should the protein be folded
incorrectly due to a mutation, such as the process that occurs in sickle cell, the protein will not
function properly. Proteins are responsible for a variety of functions, including movement,
chemical processes within the body and mechanical support.
Polysaccharides
Polysaccharides are made up of monomers called monosaccharides, or simple sugars.
Examples of monosaccharides are glucose and fructose. When the monosaccharides link up, a
polysaccharide, or complex carbohydrate, is formed. Polysaccharides are carbohydrates that are
polymers. There are four main types of polysaccharides are starch, glycogen, cellulose and chitin.
Polysaccharide
Starch
Glycogen
Cellulose
Chitin
Function
Store carbohydrates in plants
Store carbohydrates in animals
Helps forms cell walls
Structure
May be Found in…
Potatoes, wheat grains
Pasta
Trees, grass
External skeleton of arthropods
www.ualr.edu/botany/ polysaccharides.jpg
Nucleic Acids
Nucleic acids are made up of monomers called nucleotides. Each nucleotide includes a
phosphate group, a sugar and nitrogen base. When nucleotides are linked together, nucleic acids
such as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are formed. There may be up to
three billion nucleotides linked together to form a copy of DNA in humans, and one copy exists in
each of our cells (Krough, 2005). The function of DNA is to store our genetic information. RNA’s
functions include aiding in the synthesis of proteins and transporting encoded DNA (see figure 1.1).
www.accessexcellence.org/RC/VL/GG/images/rna.gif
Sickle Cell Anemia Teacher Background Information
Sickle cell anemia is a blood disorder that primarily affects people of West African descent. It is an
autosomal recessive disorder, meaning that children that receive two copies of the gene will have
the disease. Children that inherit only one copy of the gene will be carriers but generally do not
exhibit symptoms. In an area where malaria is common this is an advantage because having the
genetic mutation helped protect people from getting infected with malaria. Unfortunately over time
individuals with the heterozygous recessive gene married others with the same recessive trait. The
recessive form of the gene became much more common and more and more people inherited the
disease.
Sickle cell anemia is caused by a genetic change in hemoglobin. Hemoglobin is a protein that is
made up of chains of amino acids. Its function is to pick up oxygen in our lungs and deliver it to
other cells. It performs this function well unless it is inherited in another form called hemoglobin S.
Hemoglobin S results from a change in one nucleotide that makes up the DNA. The mRNA
transcribes the incorrect information and carries it to the tRNA. In turn, the tRNA will translate and
drop off the incorrect amino acid which forms the polypeptide. This results in a change in the fold
of the protein. Glutamic acid, which is polar and soluble in the watery cytoplasm of the red blood
cell, is replaced by valine which is non-polar and non-soluble in the cytoplasm. The valine stacks
and precipitates out in spike like formation. The result of this process is a sickle shaped cell as
opposed to the concave discs that are normally found. Because the capillaries are so tiny, they can
become clogged when the odd shaped cells attempt to pass through them. This can cause pain and
damage to tissue and organs. Sickle cells also have a shorter life span than regular blood cells
which can cause chronic anemia.
The severities of the symptoms of the disease vary from individual to individual. They cannot be
predicted based solely on genetic inheritance. Some develop life threatening symptoms as infants
but others have only mild symptoms throughout their life. Varying severity of the symptoms can be
exhibited at different times. Factors that can cause the disease to manifest itself are low oxygen,
cold temperatures and dehydration.
“There are several symptoms that warrant immediate medical attention, including the following:
•
•
•
•
Signs of infection (fever greater than 101°F or 38.3°C, coughs frequently or breathing
trouble, unusual crankiness, feeding difficulties)
Signs of severe anemia (pale skin or lips, yellowing of the skin or eyes, very tired, very
weak)
Signs indicating possible dehydration (vomiting, diarrhea, fewer wet diapers)
Other signs (pain or swelling in the abdomen, swollen hands or feet, screams when touched).
Testing can be done to determine if a child has sickle cell disease even before the child is born. The
disease cannot be cured but some of its effects can be mitigated. Preventive antibiotics are used,
making sure that a person stays hydrated is important, getting proper immunizations, avoiding stress,
and proper nutrition are important.”
http://health.enotes.com/genetic-disorders-encyclopedia/sickle-cell-disease
Goals of Lesson
Big Ideas
• There are polymers in our body that perform specific functions.
• The biological polymers need to have a certain make up to perform their function.
• Changing a structure on the molecular level influences an organism at the organism level.
Objectives
• The students will identify the three main types of biological polymers and their functions.
•
The students will be able to identify the effects of change in a polymer at the molecular level
and how it may influence the organism at the whole body level.
Students’ Prior Knowledge
Students have been learning about polymers over the course of six days. The lesson on biological
polymers and the effect of their make up on function will occur on day seven. Prior knowledge
from the polymer unit includes:
~ What is a monomer?
~ What is a polymer?
~ Examples of common/ everyday polymers
~ Synthesis / cross-linking of polymers
~ Models of monomers/ polymers (using paper clips)
Introduction to
Polymers
~ Fortune Telling Fish
~What is a monomer?
~What is a polymer?
~ Examples of
Common Polymers
Using the Internet to
Investigate Polymers
(Plastics)
Eighth Grade Polymer Unit
Playing with
Playing with
Polymers
Polymers
(Synthesize and
( Synthesize and
Collect Data for
Collect Data for
Polymer #1Polymer #2Gloop)
Ooblec)
BIOLOGIC
POLYMERS
~ Polymers in
my Body!
~ How can a
change in the
make up of a
polymer affect
its function?
Playing with
Polymers
( Synthesize and
Collect Data for
Polymer #3Goobers)
A Molecular
Model of
Polymers
(Paper Clips and
Cross Linking)
Review Polymers
Discuss Homework
(Explain how the
change in the make
up of a polymer
effect its functiondiseases)
Dr. Dad Video
Polymer Quiz
Students also have background knowledge from the seventh grade life science course. A
short review will take place at the beginning of the lesson to activate concepts learned the year
before. Prior knowledge includes:
~ Structure of the cell
~ Basic understanding of human body systems
~ Amino Acids/ Proteins (transport, enzymes etc)
~ Monosaccharides/ Polysaccharides (starch, glycogen, etc)
~ Nucleotides / Nucleic Acids (DNA, RNA, etc)
~ Molecules
Part 1 – Identifying Biologic Polymers
Hook and Informal Pre-Assessment – Hand out worksheet with a list of various substances. Have
students circle any substance that contains or is a polymer. (see attached student worksheet)
Students will work in groups of three and list as many examples of monomers and polymers in their
body as they can. Students will have resource books and web sites to use that include information
that will give examples of monomers or polymers in the body.
Suggested web site:
http://pslc.ws/mactest/maindir.htm
Expected Student Responses
Polymers
Monomers
Amino acids
Sugar (glucose, fructose)
Protein
Polysaccharides (starch, glycogen,
cellulose)
Nucleic Acid (DNA, RNA)
Nucleotides (sugar, phosphate, base
combination)
Students will take on the role of one biologic polymer (protein, polysaccharide, nucleic acid) and
will be responsible for finding examples of their polymer along with its function. (see attached
student worksheet)
Expected Student Responses
Protein
Function
Transport
Move other molecules
Enzymes
Quicken Chemical
Reactions
Hormones
Chemical Messengers
Structural
Mechanical Support
Contractile
Movement
Polysaccharides
Glycogen
Chitin
Nucleic Acid
DNA
mRNA
tRNA
Examples
Hemoglobin: Transports
oxygen through the blood
Sucrose: Positions sucrose
(table sugar) so it can be
broken down.
Growth Hormone:
stimulates growth of bones
Keratin: Hair
Collagen: Cartilage
Myosin and Actin: Allow
muscles to contract
Function
Carbohydrate storage in
animals
External skeleton of anthropods
Function
Stores genetic information
Transmits information encoded
in DNA
Uses the information of mRNA
to make proteins
Jig Saw Activity - Students will share information with original group. To insure all students have
accurate and complete information teacher will fill out data table on overhead.
Part 2 – Effects of a Change in a Polymer at the Molecular Level
Students are asked to take out their chart with information on the properties of the three polymers
that they synthesized and investigated at the start of the unit.
Students will be asked to briefly review the characteristics of the polymers.
Students will be given the specific ingredients for one of the polymers (gloop) and asked to make
changes in the ingredients following the guidelines outlined on the student worksheet. Students will
list any changes in the characteristics of the polymer. (see attached worksheet)
Teacher will call students together and they will share the results of their investigation.
List quantitatively the results of the slime test and the bounce test.
Discuss the changes that were made to get these results. (i.e. what were the specific ratios and
proportions used to get new characteristics)
Students will get into groups of four and asked to research sickle cell anemia using web sites, books,
or articles. Each group will be responsible for researching one of the following questions:
What is sickle cell anemia?
What causes sickle cell anemia?
What effects does sickle cell anemia have on your body?
How do you get sickle cell anemia?
Web Articles: http://kidshealth.org/teen/diseases_conditions/blood/sickle_cell_anemia.html
http://www.mayoclinic.com/health/sickle-cell-anemia/DS00324
http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_All.html
http://www.scinfo.org/Sickleinfosheet2.doc
http://www.scinfo.org/powerpt.htm (on line power point presentation)
Jig Saw 2 - Students will meet with representatives to share what they learned with the other
groups.
Finally, as a whole group we will discuss the findings and how they relate to the polymer
investigations.
Teaching Points
•
•
•
•
•
Polymers are made up of smaller components called monomers.
There are three main types of biological polymers.
The make up of biological polymers determine their function.
A change in one nucleotide (monomer) that makes up the DNA (polymer) leads to the
incorrect transcription from the mRNA (polymer) to the tRNA (polymer.) The tRNA
translates and delivers the incorrect amino acid (monomer) which forms the polypeptide.
This results in a change in the fold of the protein (polymer.)
The properties of anything made out of polymers really reflect what's going on at the ultratiny (molecular) level. So, things that are made of polymers look, feel, and act depending on
how their atoms and molecules are connected, as well as which ones we use to begin with!
Connection to Enduring Understanding
•
•
•
•
Molecular Level – Polymer make up can cause a malfunction in a structure.
Cellular Level – Red blood cells are sickle shaped as a result of incorrect make up. Sickle
cells expire more quickly due to shape.
Tissue/System – Circulatory system malfunctions because the capillaries become clogged
with the sickle shaped cells.
Whole Body Organism – painful, causes damage to tissues and organs, premature death
rate.
Assessment and Homework – Differentiated Expectations
Lower Level
Explain how a change at the molecular level (gene mutation) may affect an organism at the whole
body level. (Effects of sickle cell anemia on the body)
Middle Level
Research Tays Sachs disease or Hemophilia. Explain the causes of the disease and how it affects
the body.
Gifted
Research Tays Sachs disease or Hemophilia and compare their genetic mutations with sickle cell
anemia.
Name: ________________________________ Date: ____________ Period:_____
Biological Polymers
Directions:
Assign each student in your group one of the three main types of biological polymers (protein,
polysaccharide, nucleotide) and break up into new groups with other students who were also
assigned that polymer. After filling in the correct information below, you will come back to your
original group to teach the other group members about the biological polymer you researched.
Proteins:
Look at the list of the specific types of proteins below. For each of the specific proteins, explain
the function and an example.
Protein
Transport
Enzyme
Hormones
Structural
Contractile
Function
Polysaccharides:
What is the function of Glycogen?
What is the function of chitin?
Nucleotides:
What is the function of DNA?
What is the function of m-RNA?
What is the function of t-RNA?
Example
Effects of a Change in a Polymer at the Molecular Level
Directions:
Look at your polymer data table, specifically POLYMER #1. Briefly discuss the characteristics
(bounciness, slime rating, etc) of that polymer with your group. Following the below guidelines,
create a different polymer using the same ingredients that you used to synthesize POLYMER #1.
Guidelines:
You may use any amount of white glue between 1mL and 20 mL.
You may use any amount of sodium borate solution between 1mL and 20 mL
How much glue did your group decide to use? _________mL
How much sodium borate solution did your group decide to use? ___________mL
List the characteristics of your new polymer:
Characteristic
Description
Slime Rating
Slow Poke Test
Quick Poke Test
Slow Pull Test
Quick Pull Test
Blob Test
Hang Test
Bounce Test
Newly Synthesized Polymer
Questions:
How did changing the amount of glue and sodium borate solution change the characteristics of your
newly synthesized polymer?
What is the ratio of the original amount of glue to the new amount of glue?
___________:_______________
What is the ratio of the original amount of sodium borate solution to the new amount of sodium
borate solution?
___________:_______________
Group _______________________________
Date ______________________
_______________________________
Period_____________________
_______________________________
_______________________________
Sickle Cell Anemia
What is sickle cell anemia?
What causes sickle cell anemia?
What effects does sickle cell anemia have on your body?
How do you get sickle cell anemia?
Name: ________________________________ Date: ____________ Period:_____
Circle the items that are polymers in red!
Circle the items that contain polymers in black!
If the item is not a polymer or does not contain one cross it out!
Wood, Food, Rubber, Water, Plastic, Bottles,
Styrofoam, RNA, Chewing Gum, Latex Paint,
Cellulose, Trees, Bugs, Humans, Cows, Shoes,
Whales, Walruses, Fungus, Crabs, Lobster Shell,
Plants, Silk, Wool, Bullet, Polysaccharides, Proof
Vests, Tires, French Fries, Rubber Bands, Foam,
Amino Acids, Nucleotides, DNA, Chitin, Sugar,
Nucleic Acid
Pictures: http://srs.dl.ac.uk/Annual_Reports/AnRep02_03/cd12-fig3.jpg
http://polymers.case.edu/images/dna.jpg