Download HBS L-3

Lesson 3
Exploring Carbohydrates
Objectives
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Recognize that carbohydrates are one of three
major food types.
Indicate that sugar and starch are forms of
carbohydrates.
Perform chemical tests to determine the
presence of sugar and starch in five foods.
Explain that carbohydrates are a major source
of energy for the human body.
Terms
3.1 Indicator
3.2 Carbohydrates
3.3 Sugar
3.4 Starches
3.5 Proteins
3.6 Amino Acids
3.7 Saturated Fats
3.8 Unsaturated Fats
3.9 Vitamins
3.10 Minerals
3.11 Water
3.12
3.13
3.14
3.15
3.16
3.17
3.18
Benedicts Solution
Lugols Solution
Complete Proteins
Incomplete Proteins
Fats
Monosaccharide
Polysaccharide
Question:
How can you determine
if sugar or starch is
present in food?
Hypothesis:
I believe you can
determine the presence
of sugar/starch
by…because…
Data:
Safety!!!!
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Don’t taste or eat the food!!!!
Don’t touch the test tubes after they come out
of the hot bath!!!!
Don’t get Benedict’s solution on your skin—if
you do rinse it off immediately.
Lugol’s will stain.
If you get lugol’s on you—notify me
immediately.
Procedure
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Mark the lab cups as indicated on page 17 in
student guide.
Mark the scoops 3, 4, 5
Using 6 test tubes, mark these 1-5 & DW.
Add the materials in the cup according to the
following chart.
Stir each cup—use a different toothpick!!!!!
Add the following materials to the
lab cups as follows:
1
45 drops sugar
solution
3
5
2
4
DW
One Marshmallow
45 drops distilled
water
2 scoops egg white
45 drops distilled
water
45 drops distilled
water
2 scoops potato buds 2 scoops starch
45 drops distilled
45 drops distilled
water
water
Testing for Sugar
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Make sure the materials in each cup have been
stirred.
Use a different pipette for each test tube
In each test tube place 20 drops of the liquid
that was in the cup.
Make sure the test tube # matches the cup #!!!
Add 10 drops of Benedict’s solution to each
test tube.
Testing for Sugar
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Attach the clamp to the test tube.
Two members of the group will take a test tube
and place it in the water bath for one minute.
Do not hold onto the test tube while it is in the
water bath.
Repeat this procedure until all 6 test tubes have
been heated.
Record any color changes on the handout.
Testing for Starch
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Make sure the sugar test has been completed.
Add 3 drops of Lugol’s solution to each cup in
the lab tray.
Look for color changes in the solid food
instead of the liquid if the food hasn’t
dissolved.
Record findings on the student sheet.
Data/Results
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Record your results in your table
Conclusion
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Write a paragraph stating your results. Be sure
to discuss the role of Benedict’s and Lugol
solutions.
Clean-up Roles
Test-tube
clean-up
Pour contents
down
sink/waste
bucket.
Scrub test
tubes in soap
water.
Place in clean
water bucket.
Lab-tray
clean-up
Empty solids
into trash.
Rinse scoops
in distilled
water.
Clean lab
tray in soapy
water.
Pipette
clean-up
Rinse pipette
in soapy
water.
Rinse in
clean water
Lab Station
clean-up
Make sure
all lids are
back on all
materials
Put all
materials
back into
tote tray.
Terms
3.1 Indicator
3.2 Carbohydrates
3.3 Sugar
3.4 Starches
3.5 Proteins
3.6 Amino Acids
3.7 Saturated Fats
3.8 Unsaturated Fats
3.9 Vitamins
3.10 Minerals
3.11 Water
3.12
3.13
3.14
3.15
3.16
3.17
3.18
Benedicts Solution
Lugols Solution
Complete Proteins
Incomplete Proteins
Fats
Monosaccharide
Polysaccharide
Terms
3.1 Indicator – Demonstrates the presence of a substance
3.2 Carbohydrates – Major source of energy for the body
(sugars/starches)
3.3 Sugar – Occurs as Mono and Disaccharides. Form as
glucose easily used by the body.
3.4 Starches – Polysaccharide. Must be broken down into
Monosaccharide to be used by the body.
3.5 Proteins – Build and repair body. Made up of chain of
amino acids.
3.6 Amino Acids – Make up proteins and are essential for
health.
3.7 Saturated Fats – Comes from animals and can be
converted into cholesterol (bad fats!)
3.8 Unsaturated Fats – Comes from plants, nuts, and seeds
and is converted into energy (better fats!)
Terms
3.9 Vitamins – Chemicals made by living organisms.
3.10 Minerals – Chemicals made naturally in the environment.
3.11 Water – Nutrient in the body. H20.
3.12 Benedicts Solution – Indicator for Sugar.
3.13 Lugols Solution – Indicator for Starch.
3.14 Complete Proteins – A food that has all 9 essential amino
acids.
3.15 Incomplete Proteins – A food that does not have all 9
essential amino acids.
3.16 Fats – Provides energy and insulates the body.
3.17 Monosaccharide – Simple sugar. Provides energy.
3.18 Polysaccharide – Chain of sugars = Starch. Broken
down to provide energy.