Transcript Macromolecules - Hudson City School District

Macromolecules
Standard Qualitative Tests
and
Testing Your Own Food
Qualitative
• Detecting if a
substance is present
• You don’t know how
much
SAFETY
• IF A SOLID, cut into little pieces
• Rinse razor blades under water,
do not wipe across the blade
• Put used blades at the end of the
period in the “used beaker” on the
cart
Goggles and Apron
• Chemicals
are caustic to
your eyes
• Iodine stains
When it asks for…
• Dropper Full
• Just squeeze to
fill dropper and
release
• Exact amounts
are not important
• 1 dropper full =
20-30 drops
Pasteur Pipets
NEVER EVER
• NEVER, hold a
filled pipet
upside
down…or hold
on its side…
You contaminate
the bulb
For 5mL and 10 mL
• ACID
• SUCROSE
Controls
• Positive Control • Negative Control
• Absolutely expect • Absolutely expect
to see the result
to NOT see the
result
• Use the substance
(starch, glucose,
• (may use water)
etc.)
Lab Objective:
• Describe the test that
indicates the presence of
most small
sugars.
Recording Benedict’s Results
•
•
•
•
•
blue
+
blue/green
++ green
+++ yellow
++++ orange/red
no sugar
trace
little sugar
some sugar
much sugar
Benedict’s Sugar Test
Lab Objectives:
• Describe the test that
indicates the presence
of starch.
• IODINE IS POISONOUS!!!
Iodine Test
negative
positive
Lab Objective:
• Define hydrolysis and give an
example of the hydrolysis of
carbohydrates.
• ANIMATION LINKS:
Animation: Enzyme Action and the
Hydrolysis of Sucrose
• Hydrolysing starch
• WHFoods: How Does Digestion Work
and How Can I Improve Mine?
(Animated graphics)
Hydrolysis
“break with water”
to make monomers
Lab Objective:
• Give examples of the
formation/ breakdown of a:
• monosaccharide
• disaccharide
• polysaccharide
Lab Objective:
• Name the
monosaccharide
components of sucrose
and starch.
Polysaccharide
Disaccharide
(sucrose)
Monosaccharide (glucose)
Two Common Monosaccharides
Simple Sugars
• Called monosaccharides
• primary function = energy
• Your SAMPLE will be
glucose
Disaccharide
• Double Sugar
• Combined simple sugars
• YOUR SAMPLE WILL
BE SUCROSE
Disaccharide
Now Let’s Demonstrate how
Digestion Might Work
• Click Here Howstuffworks "The Digestive
System"
Tube 1blue (-) still sucrose, a disaccharide
2
1
Tube 2- heat broke bonds
–so tested orange (+) for
glucose
Tube 3
• Negative for
because it is
starch (a
polysaccharide)
STARCH
Polysaccharides
• Shorter sugars link together to
form complex sugars
• Your starch sample will be
POTATO STARCH
glucose
Tube 4
Starch Not
heated – so
it would be
(+) for
iodine, blueblack
Tube 5
• Heated 5 minutes – added Benedicts
• Starch may just start to break down, so just a little (+)
for glucose or (-) starch did not break down yet
here
Tube 6
• Heated 5
minutes added
Iodine
• Brown –
somewhat
broken down –
so just partially
(+) for starch
Tube 6
Tube 7
• Heated 15 minutes
• Added Benedicts (for a glucose test)
Starch is broken down to its monomers,
glucose
Tube 7
Tube 8
• Heated 15
minutes – Tested
for starch
• Negative,
because it is
broken down to
glucose
TUBE 8
Explain Benedict’s test on sucrose
• AT first sucrose is (-) with
Benedicts because it is a
disaccharide.
• After hydrolysis (heating and
acid), the monosaccharide
glucose is (+)
Explain the iodine test with starch
• At first starch is (+) with
iodine.
• After hydrolysis, the starch
breaks down to glucose and
tests (-) with iodine.
Explain Benedicts with starch.
• At first starch would be (-) for it is
not glucose, but is a
polysaccharide.
• After hydrolysis, glucose is formed
when the bonds break.
Why does hydrolysis of starch take
longer than of sucrose?
• Starch is a
polysaccharide,
more bonds to
break.
• Sucrose is a
disaccharide.
Cellulose
Dehydration Synthesis
take out water to make
macromolecule
Complex Carbohydrates
• Starch -storage in plants
• Cellulose -fiber
• Glycogen-storage in animals
Testing for Fats and Proteins
• Read Lipids Intro p. 9 and answer the
questions to the left (3)
• Read Proteins Intro p. 10 and answer the
questions to the right (3)
• Mrs. Sheldon will demonstrate the
Separation of Butter lab.
Fat Test with Brown Paper
Translucent (light can go through)
= + fat test
Protein Test with Biuret’s
Describe the Protein Test
• Biuret’s is what color?
• Blue
• In the presence of a protein it will
turn what color?
• purple
Biurets turns purple in the presence
of protein
Neg.
Lots
Slight
Separation of Butter
• Clarification is removing lipid
part (water insoluble) from nonlipid part (water-soluble).
• Why do it? Clarifying butter raises
the smoke point from 250oF to
350oF.
Emulsion
Oil droplets
(micelles) are
formed in watersoluble
substances
Oil is non-watersoluble
Heat breaks up the Emulsionseparates the butter
Ghee
A common food fat in India, ghee is
produced from boiled buffalo milk. Its
manufacture is similar to that of butter oil.
It can be kept for months, or years, without
refrigeration, and has a more intense flavor
than butter or butter oil.
Clarified Butter (Ghee)
separated into:
Protein foam
on top skimmed off
Next layer
= clarified butter
Bottom layer =
milk solids - flavor
BRING IN FOODS TO TEST
• We can grind,
chop, dilute them
to make them
dissolve in water
• We will run all
the tests on them
While you Wait…
• Do exercises from the handouts:
– Lipid Crossword
– Exercise 6
– Exercise 7
– If you have trouble, use text CD