Download Carbohydrates

Teacher’s Guide
EXPLORE
Part I: Testing Known Substances
Teacher Prep:
1. Prepare and label four Erlenmeyer flasks and disposable pipettes with the following suggested solutions
and place them in the front of the room for easy access for students:
a. Polysaccharide Solution - blended potato or lab grade starch solution
b. Monosaccharide Solution – apple juice or lab grade glucose solution
c. Protein Solution – blended meat or egg whites
d. Lipid Solution – vegetable oil, melted butter
2. Set up 4 lab stations (twice around the room) for students to rotate. Each station should have the
materials needed to conduct one of the following tests:
a. Iodine Test: starch + iodine (yellowish orange)  blue-black
Ex. Potato solution
b. Benedict's Test: monosaccharide + Benedict's solution (light blue)  green to red depending on
concentration of sugars
Ex. apple juice or glucose solution
c. Biuret's Test: protein solution + Biuret’s solution (light blue)  pinkish purple
Ex. meat , egg white
d. Paper Bag (Translucence) test
3. At each station, have the indicator test procedure card, the biomolecule information card for the
biomolecule being tested at the station, and all lab supplies required to conduct the test. It is
recommended that the two lab stations in the front be designated for the Benedicts test which requires a
hot water bath.
Procedure
4. Have students read the background information and complete the Pre-Lab questions for Part 1 as the
journal activity for the day.
5. Demonstrate to students what equipment and basic procedures they will be applying during this exercise.
6. Have students get into groups of 2-3 and rotate through all 4 stations and record their results.
7. Have students return to their desks but stay with their groups to complete the Analysis Questions in their
journals.
Alternate indicators:
 Iodine for lipids/oil (turns pink but transformation is temporary so watch carefully)
 Biuret Solution is easy to make. Start with 40% NaOH and then sprinkle in copper sulfate until you get a
nice blue color.
 Nitric acid for proteins (turns yellow in the presence of proteins, stays clear if none are present).
o Students need to take the proper cautions when working with nitric acid to prevent contact with skin or
clothing. It becomes really easy to see who did not take proper precautions because they can be caught
yellow-handed.
 Water solubility test for fats (the presence of fats makes an insoluble layer on top of the water). This test
can be difficult at times to detect based on the type of substance and amount of fat in it.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
ELABORATE
Part II: A Lesson in Urinalysis
Teacher Prep:
1. Prepare and label four Erlenmeyer flasks and disposable pipettes with the following synthetic urine
solutions and place them in the front of the room for easy access for students:
Synthetic Urine Recipes
Each student group needs about 10 mL of a sample for testing. These recipes make about 60 mL of each
sample.
Stock Urine:
 160mL water
 Yellow food coloring
 2g NaCl
Urine Sample from Patient #H 987
(High glucose)
 40mL apple juice
 20mL stock urine
Urine Sample from Patient #L 623
(High protein)
 60mL stock urine
 5mL egg albumin
Urine Sample from Patient #P 552
(High glucose & protein)
 40mL apple juice
 20mL stock urine
 5mL egg albumin
Urine Sample from Patient #M 340
(High protein & High starch – contaminated sample!)
 50mL stock urine
 5mL egg albumin
 5mL starch
2. Set up 3 lab stations (2-3 times around the room) for students to rotate. Each station should have the
materials needed to conduct one of the following tests:
a. Iodine Test: starch + iodine (yellowish orange)  blue-black
Ex. Potato solution
b. Benedict's Test: monosaccharide + Benedict's solution (light blue)  green to red depending on
concentration of sugars
Ex. apple juice or glucose solution
c. Biuret's Test: protein solution + Biuret’s solution (light blue)  pinkish purple
Ex. meat , egg white
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
3. At each station, provide the Macromolecule Lab: Urinalysis experimental procedure and all lab supplies
required to conduct the test. It is recommended that the 1-2 lab stations in the front be designated for the
Benedicts test which requires a hot water bath.
4. As the journal questions for the day have students complete the Pre-Lab questions for Part 1.
5. Demonstrate to students what equipment and basic procedures they will be applying during this exercise.
6. Have students get into groups of 2-3 and rotate through all 4 stations and record their results.
7. Have students return to their desks but stay with their groups to complete the Analysis Questions in their
journals.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Macromolecule Lab: Using Indicators
Purpose
The purpose of this exercise is to determine how to use chemical indicators to verify the
presence of carbohydrates (monosaccharides and polysaccharides), proteins, and lipids in
several known substances.
Background
Carbohydrates, proteins, and lipids are nutrients that are essential to all living things. Most
foods contain mixtures of proteins, carbohydrates, and lipids. These food molecules taken into
cells react to provide the chemical building blocks needed to synthesize other molecules used
for processes that the body carries out, like growth and reproduction. The atoms that make up
the macromolecules (carbon, oxygen, and hydrogen in particular) occur in different ratios and
structures that account for different properties. Indicators are chemical substances that can be
used to classify the types of macromolecule present in substances. The indicators will turn
color due to the structural differences among the macromolecules.
The individual classes of macromolecules can be described as follows. A carbohydrate is an
organic compound composed of carbon, hydrogen, and oxygen atoms in the ratio of about
two hydrogen atoms to one oxygen atom. A protein is organic molecule that is formed from
amino acids. An amino acid consists of a central carbon atom to which four functional groups
are attached. Most lipids contain fatty acids and glycerol. Nucleic acids are organic molecules
that store genetic information in the cell.
SAFETY:
Pre-Lab – Answer the following pre-lab questions using complete sentences in your lab
journals.
1. What are the four main biomolecules found in living things?
2. What is an indicator? How will they be used in this lab?
3. Based on the safety symbols below, what precautions will you expect to take in order
to perform this investigation?
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Part I: Testing Known Substances
In the first part of this lab, you will need to determine how to use chemical indicators
to verify the presence of monosaccharides and polysaccharides, proteins, and lipids in
several known substances. Your results in this section will allow you to carry out tests
on a “patient’s” urine samples to determine the presence of any of the above known
substances.
Procedure
1. Draw or paste the following data table in your journal.
Chemical
Macromolecule
Indicator
Biuret’s
Solution
Benedict’s
solution
Lugol’s
Iodine
Initial
Observation
Observations for a
Positive Test
Paper Bag
2. Visit each of the stations set up in the classroom. Follow all instructions carefully
and make detailed observations in the data chart to assist you in Part II.
3. When your group has completed all the tests at each station, return to your
desks and discuss what you have discovered during this investigation.
4. Be ready to participate in a class discussion and complete an exit ticket.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Analysis Questions (Answer in complete sentences in your journal):
1.
Which substances contain monosaccharides?
a. Which substances contain starch?
b. Which substances contain protein?
c. Which substances contain lipids?
2.
Which substances did not test positive for any of the organic compounds?
3.
What is the purpose of using distilled water as one of your test substances?
4.
What do all of the indicators you have used have in common?
5.
What conclusions could you make if a positive test for any of the organic
compounds occurred in the test tube containing distilled water?
6.
How does an indicator detect the presence of only one type of macromolecule?
7.
Is there a macromolecule that the tests in this lab did not test for? If so, list the
kinds of macromolecules not tested, and give one reason why they were not
tested.
8.
Which compound is most common in foods that come from plants?
9.
If you wanted to reduce the amount of fat in your diet, what foods would you
avoid?
10. Which foods tested would your body use for a quick burst of energy?
a. For energy when no carbohydrates are available?
b. For building body parts?
__
____
____
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
_
______Part I
Protein Test Station Card - Biuret Solution
Materials
 Substance tested Protein solution
 Indicator - Biuret
solution
 Test tubes
 Dropper
 Supplies to clean and
dry test tubes
Procedure
1. This is the station where you will use Biuret’s
solution to test for the presence of proteins.
2. Locate a test tube, the protein solution, and the
Biuret solution.
3. Shake the protein solution. Then add 1-2 drops
into the test tube.
4. Now, add 2-3 drops of Biuret solution. Swirl the
solutions together.
5. Record any observable change in color.
6. Replace all materials. Clean out your test tube
using soap, water, and a test tube brush. Place
your test tube into the rack to dry.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Lipid Test Station Card - Paper Bag
Materials
 Substance tested –
Lipid (vegetable oil )
solution
 Indicator - Paper bag
 Dropper
 Test tubes
Procedure
1. This is the station where you will use the paper bag
test to check for the presence of lipids (fats).
2. Obtain a test tube, the vegetable oil, and a piece of
brown paper bag.
3. Add 1-2 drops of vegetable oil to the brown paper.
Record what you see. Describe how the paper looks.
4. Repeat step 3 using water on a different piece of
brown paper. Record what you see.
5. Compare your two results and come up with a good
description of how the paper test can be used to
test the presence of lipids.
6. Replace all materials. Clean out your work area.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Monosaccharide Test Station Card - Benedict’s
solution
Materials
 Substance tested Monosaccharide solution
 Indicator - Benedict’s
solution
 Test tubes




Hot water bath
Test tube holder
Dropper
Supplies to clean and dry
test tubes
Procedure
1. This is the station where you will use Benedict’s solution to
test for the presence of monosaccharides (simple sugars).
2. Locate a test tube, a test tube holder, the monosaccharide
solution, and the Benedict’s solution.
3. Add 4-5 drops of the monosaccharide solution to the test
tube.
4. Now, add 4-5 drops of the Benedict’s solution. Swirl the
solutions together.
5. Carefully place your test tube into the hot water bath using
the test tube holder. (Caution: water is HOT!)
6. Record the change in color that is seen (green indicates a
low concentration of monosaccharides – brick red indicates
a high concentration). Also, note how long it took for the
color to change.
7. Replace all materials. Clean out your test tube using soap,
water, and a test tube brush. Place your test tube into the
rack to dry.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Polysaccharide Test Station Card - Lugol’s
Iodine
Materials
 Substance tested Polysaccharide (Starch)
solution
 Indicator - Iodine
solution
 test tube
 Dropper
 Supplies to clean and dry
Procedure
1. This is the station where you will test for the presence
of polysaccharides (starch).
2. Shake the polysaccharide (starch) solution. Then add
1-2 drops into the test tube.
3. Note the color of the iodine solution. Now, add 1-2
drops of the Iodine solution.
4. Record the change in color that you observe.
5. Replace all materials. Clean out your well plate using
soap and water. Place your well plate on the paper
towel to dry.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Cut and paste into lab notebook.
Chemical
Indicator
Macromolecule
Initial
Observation
Observations
for a
Positive Test
Initial
Observation
Observations
for a
Positive Test
Biuret’s
Solution
Benedict’s
solution
Lugol’s Iodine
Paper Bag
Cut and paste into lab notebook.
Chemical
Indicator
Macromolecule
Biuret’s
Solution
Benedict’s
solution
Lugol’s Iodine
Paper Bag
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Lab: Macromolecule - A Lesson in Urinalysis
Background
A healthy diet abundant with foods that contain each of the macromolecules
insures proper function of all the body’s cells, tissues, organs, and organ systems. If
one or more are lacking, the body cannot function to provide us with all of our
necessary needs.
Your kidneys filter waste products from your blood while retaining components
your body needs — including proteins and sugars. The kidneys take out waste material,
minerals, fluids, and other substances from the blood to be passed in the urine. Urine
has hundreds of different body wastes. What you eat, drink, how much you exercise,
and how well your kidneys work can affect what is in your urine.
Urine can contain important information about a patient’s (human or animal)
health status. A test called a urinalysis, or “UA”, is done to check for infections of the
urinary tract or for the presence of blood, glucose, or protein in the urine.
The composition of urine varies depending on diet and activity. Urine is about
95% water, but it also contains urea and uric acid. Sometimes traces of amino acids can
be found in urine, as well as a variety of electrolytes. In this activity, you will be
analyzing a “patient’s” urine for the presence of carbohydrates, proteins, or lipids.
Glucose is the type of sugar found in blood. Normally there is very little or no
glucose in urine. When the blood sugar level is very high, as in uncontrolled diabetes,
the sugar spills over into the urine. Glucose can also be found in urine when the
kidneys are damaged or diseased.
Some diseases and conditions can allow proteins to pass through the filters of your
kidneys, causing protein in urine. Protein is normally not found in the urine. Low levels
of protein in urine are normal. Temporarily high levels of protein in urine aren't
unusual either, particularly in pregnant individuals, younger people after hard exercise,
or during an illness. However, abnormally high amounts of protein found in a urine
(proteinuria or microalbuminuria) is often a sign of kidney disease and can be used to
detect the early signs of kidney damage.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Pre-Lab Questions – Answer the following pre-lab questions in complete
sentences in your lab journals.
1. What are the monomers of protein, and what element(s) do they contain that
carbohydrates and lipids do not?
2. Explain why you have to test for the presence of macromolecules in known
substances first before you test unknown samples?
3. Using the following sentence stem, formulate a hypothesis regarding your
patient’s urine sample.
If Patient # _______’s urine tests positive for (protein/glucose/starch), then
his/her sample indicates a (contaminated sample/risk of diabetes/sign of kidney
disease).
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
MATERIALS
 Urine sample*
Patient #M 340
Patient #P 552
Patient #L 623
Patient #H 987






Macromolecule Lab: Urinalysis
Purpose
To test urine samples for the presence of monosacchrides,
polysaccharides, and protein in order to diagnose a patient with
diabetes or kidney disease.
3 test tubes
Test tube rack
Test tube tongs
Biuret solution
Iodine solution
Benedict’s
solution
 Hot plate with
water bath
Procedure
Part 2
SAFETY
2. Conduct the following three tests on the urine sample:
a. Monosaccharide (Simple sugar) Test
 Add 1-2 drops of the urine sample to a clean test tube.
 Add 1-2 drops of Benedict’s solution to the sample.
 Heat the sample for 1-2 minutes in a hot water bath.
 Record your results in the data table.
1. Draw the following data table in your lab journal.
Urine Sample #:
Macromolecule
Chemical
Indicator
Prediction
Present (+)
Absent (-)
Monosaccharide
(simple sugar)
Polysaccharide
(starch)
Protein
b. Polysaccharide (Starch) Test
 Add 1-2 drops of the urine sample to a clean test tube.
 Add 1-2 drops of Lugol’s iodine solution to the sample.
 Record your results in the data table.
c. Protein Test
 Add 1-2 drops of the urine sample to a clean test tube.
 Add 1-2 drops of Biuret’s solution to the sample.
 Record your results in the data table.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
3. When your group has completed all the tests at the stations, return to your desks
and discuss what you have discovered during this investigation. Make your
diagnosis based on your data.
4. Be ready to participate in a class discussion and complete a conclusion paragraph
as an exit ticket.
Conclusion
In paragraph form, write a summary of the experiment, analysis of data, and a
discussion of any sources of error if any occurred.
Make sure to include the following information in your conclusion paragraph(s):
a) For which patient did you do your urinalysis tests?
b) What was your original hypothesis?
c) What was the independent variable in your experiment?
d) What was your dependent variable?
e) What were your results? Which macromolecule(s) were present in your patient’s
urine?
f) Did your results support your hypothesis?
g) Can you make a diagnosis about your patient? If so, what is it?
h) Where there any errors in your tests that could have affected your results?
Niesen, Lorilee (2008). Macromolecule Lab; A Lesson in Urinalysis. Maxwell High School Ag.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #5150
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret
Answer:
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #5150
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret
Answer:
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #5150
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret
Answer:
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #0560
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret
Answer:
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #0560
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret
Answer:
Name _____________________________________________ Date ___________________ Period __________
EXIT TICKET: Urinalysis Patient #0560
A student conducted a urinalysis test on two urine samples. Evaluate the results and
indicate which macromolecules are present and explain why.
Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret
Answer:
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Carbohydrates
Function
Carbohydrates are found in
foods such as:
Simple sugars include:

table sugar and honey
Living things use carbohydrates as their
main source of energy. Plants and some
animals also use carbohydrates for
structural purposes. Starches and sugars
are examples of carbohydrates that are
used by living things as a source of
energy.
Complex carbohydrates include:







Grains, cereals, and pasta
Breads, tortillas, crackers,
bagels
Dried beans, split peas and
lentils
Vegetables, like potatoes,
corn, and peas
Fruit
Milk and yogurt
Foods and drinks made with
sugar, like regular soft drinks
and desserts
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Glucose is the most common sugar unit
in our food and in our bodies. Besides
glucose, monosaccharides include
galactose, which is a component of milk,
and fructose, which is found in many
fruits.
The polysaccharide, starch, is stored in
plant fruits and seeds. Another
carbohydrate found in plants is
cellulose, a very straight and stiff
material, which is a major component of
cell walls. Animal starch, glycogen, is
stored in the liver of many animals.
Structure
One of the four groups of organic compounds
found in living things is carbohydrates.
Carbohydrates are compounds made up of
carbon, hydrogen, and oxygen atoms, usually
in a ratio of 1:2:1, for example, glucose has
the formula C6H12O6.
The building blocks of carbohydrates are ring
shaped molecules called monosaccharides
(mohn-oh-SAK-uh-rydz). Glucose is an
example of a monosaccharide. Carbohydrate
is sugar – and includes both single sugar units
called monosaccharides and chains of sugar
units chemically linked together called
polysaccharides (poh-li-SAK-uh-rydz). Starches
form when sugars join together in a long
chain.
Carbohydrates have to be broken down into
single sugar units to be absorbed.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Lipids
One of the four groups of organic compounds found
in living things are lipids.
Lipids are a large and varied group of biological
molecules that are generally insoluble (does not
dissolve) in water. The common categories of lipids
are fats, oils, and waxes. A fat is a solid at room
temperature, while an oil is a liquid under the same
conditions.
Lipids are made mostly from carbon and hydrogen
atoms. The building blocks of lipid molecules are
fatty acids and glycerol.
There are different functions for
lipids in our bodies:
 Lipids can be used for longterm energy storage.
 Some lipids called
phospholipids form biological
membranes like the
membranes around our cells.

Form waterproof coverings

Hormones and vitamins
Phospholipids serve an extremely important function in our bodies,
they form the cell membrane. The fatty acid chains are usually
between 10 and 20 carbon atoms long. The fatty "tail" is non-polar
(hydrophobic) while the carboxyl "head" is a little polar (hydrophillic).
A cell as being surrounded by a flexible fence called the cell
membrane. The cell membrane is composed of two layers, each
composed of trillions of phospholipid molecules oriented in a special
manner.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
If each carbon atom in a lipid's fatty
acid chains is joined to another
carbon atom by a single bond, the
lipid is said to be saturated.
The term saturated is used because
the fatty acids contain the maximum
possible number of hydrogen atoms.
If there is at least one carbon-carbon
double bond in a fatty acid, the fatty
acid is said to be unsaturated.
The fatty acids in oils are mostly unsaturated, while those in fats are mostly saturated.
oil
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
butter, margarine
Proteins
One of the four groups of organic compounds
found in living things is proteins.
Proteins are found in:






Beef and pork
Poultry
Fish and shellfish
Eggs
Dairy products like cottage cheese and
regular cheese
Plant-based proteins like beans, nuts,
and tofu
Protein is an essential part of your diet -and your body. But, too much of a good
thing can be bad for you. Most meats
have fat as well as protein. So, excess
protein from animal sources can mean
excess calories and fat – which means a
greater chance at gaining weight.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Functions of Various Proteins
Antibodies - are specialized proteins involved in
defending the body from antigens (foreign invaders).
Contractile Proteins - are responsible for movement.
Proteins such as actin and myosin are involved in muscle
contraction and movement.
Enzymes - are proteins that facilitate biochemical
reactions. They are often referred to as catalysts because
they speed up chemical reactions.
Hormonal Proteins - are messenger proteins which help
to coordinate certain bodily activities. Insulin regulates
glucose metabolism by controlling the blood-sugar
concentration.
Structural Proteins - are fibrous and stringy and provide
support. Keratin strengthen protective coverings such as
hair, quills, feathers, horns, and beaks. Collagen and
elastin provides support for connective tissues such as
tendons and ligaments.
Storage Proteins - store amino acids. Ovalbumin is found
in egg whites and casein is a milk-based protein.
Transport Proteins - are carrier proteins which move
molecules from one place to another around the body.
Hemoglobin transports oxygen through the blood.
Primary Structure
Secondary Structure
Tertiary Structure
Structure
Proteins vary in structure as well as function. They are
constructed from a set of 20 amino acids and have distinct
three-dimensional shapes.
The structure of a protein determines its function. For
example, collagen that is found in hair and skin, has a supercoiled helical shape. It is long, stringy, strong, and resembles a
rope. This structure is great for providing support.
Hemoglobin on the other hand, is a globular protein that is
folded and compact. Its spherical shape is useful for moving
oxygen through blood vessels.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm
Quaternary Structure
Nucleic acids
The building blocks of nucleic
acids are nucleotides.
Nucleotides are made of three
parts: a phosphate group, a
sugar, and a nitrogen base.
Nucleotides link together to
form long strands.
Function
The main function of nucleic acids is
to store and transmit genetic
information and use that information
to direct the synthesis of new
protein.
Functions of DNA (deoxyribonucleic acid):
 DNA is a permanent storage place
for genetic information.
 DNA controls the synthesis of RNA
(ribonucleic acid).
 The sequence of nitrogenous bases
in DNA determines the protein
development in new cells.
Functions of RNA (ribonucleic acid):
 RNA transmits genetic information
from DNA to the protein factories
(ribosomes) in the cell. RNA also
directs the synthesis of new
proteins using the genetic
information it has transported.
Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm