Testing for Organic Macromolecules. What are Macromolecules? Large molecules made of smaller...
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Transcript of Testing for Organic Macromolecules. What are Macromolecules? Large molecules made of smaller...
Testing for Organic Macromolecules
What are Macromolecules?• Large molecules made of smaller
molecules
Or
Small molecules
Or
Macromolecule
What do we mean by Organic?
• Compounds that contain the atom Carbon are considered organic.
• All living things are made of organic molecules!
There are four classes of Organic Compounds
1. Carbohydrates
2. Proteins
3. Lipids
4. Nucleic acids
Indicators
• Are substances used to test for the presence of specific chemical compounds.
• Have a known response to specific chemical compounds.
• Indicate whether a chemical compound is present in the solution you are testing.
• The slides that follow have instructions for using specific indicators to test for four specific organic compounds!
• Use these notes as procedures for your lab today and for your final lab write up.
**Note: You will find out which compound each indicator tests for next week when we take notes on each category of organic compounds.
Indicator: BROWN PAPER1. Dip the clean end of a cotton swab into the
solution you are testing, swirl it around.
2. Wipe a thin layer of the SOLUTION you are testing ONTO BROWN PAPER. If you put to much on, dab it off with paper towel
3. WAIT FOR IT TO COMPLETELY DRY (do this test first so you have plenty of drying time)
4. A TRANSLUCENT SPOT (LIGHT SHINES THROUGH) is a positive test result.
***Any other change or no change is a negative result!
1. Wash your test tube!2. Stir the solution you are testing, then add 3
ml to your test tube. 3. Add 15 drops of Benedicts (the indicator) to
3 ml of the solution in the test tube. 4. Swirl test tube to mix. 5. Heat solution, in a water bath, for
approximately 1-2 min.6. If the solution turns orange, this is a positive
result. ***Any other change or no change is a negative result!
Indicator: BENEDICT’S
Indicator: BIURET’S
1. Wash your test tube!2. Stir the solution you are testing, then add 3 ml
to your test tube. 3. Add 10 drops of Biuret’s to 3 ml of solution in
the test tube.4. Swirl test tube to mix.5. A positive test result is if the solution turns
purple. (hold up to white paper if not sure)
***Any other change or no change is a negative result!
Indicator: IODINE1. Wash your test tube!2. Stir the solution you are testing, then add 3
ml to your test tube. 3. Add 10 drops of Iodine to 3 ml of solution in
the test tube.4. Swirl test tube to mix.5. A positive test result is if the solution turns
dark blue or black.
***Any other change or no change is a negative result!
Use the graduated cylinder to
measure out 3 ml.
After measuring, put the solution you are testing into the test
tube, then add indicator and swirl!
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