Chemistry of Life The Essential Ingredients for Life

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Chemistry of LifeThe Essential Ingredients for
Life
Cornell notes pg 17 in your INB
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Ingredients for Life

1. Water
2. Carbohydrates
3. Lipids
4. Proteins
5. Nucleic Acids

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Properties of water

• Living organisms are made mostly of water
• Adhesive (adhere to other surfaces)
• Cohesive (adhere to each other)
• The universal solvent
• Why does water have these special properties???

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because water is POLAR!

• Polar molecules have an uneven charges.

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Carbohydrate
(make sure to illustrate and label figures)

• Store short term energy
• Simple sugar (monosaccharide) glucose
• Complex sugar (polysaccharide) - starch

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Lipids

• insoluble (do not dissolve) in water
• stores the most energy
• Ex 1. Fats
• 2. Oils
• 3. Cholesterol
• Some functions of lipids
• 1. Long term energy storage
• 2. Insulation
• 3. Major component of membranes (phospholipids)

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Proteins

• Amino acids (20 different kinds)
• Amino Acids bonded together form a chain called a
  polypeptide chain.
• A polypeptide chain folds into a protein.
• Some functions of proteins
• 1. Transport hemoglobin in red blood cells
• 2. Movement muscles
• 3. Structural membranes, hair, nails
• 4. Enzymes cellular reactions

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Nucleic acids

• Two types
• a. DNA (deoxyribonucleic acid)- genetic
  material
• b. RNA (ribonucleic acid)-copy of genetic
  material
• Nucleic acids are composed of long chains of
  nucleotides

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Identifying Organic Compounds Lab
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PRE-LAB QUESTIONS

• How do you know if a food contains protein?
• How do you know if a food contains starch?
• What is the difference between starch and sugar?
• Why should you be careful of biuret solution?
  What should you do if you spill some on yourself?

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Introduction
The most common organic compounds found in living
organisms are lipids, carbohydrates, proteins,
and nucleic acids. Common foods, which often
consist of plant materials or substances derived
from animals, are also combinations these organic
compounds. Substances called indicators can be
used to test for the presence of organic
compounds. An indicator is a substance that
changes color in the presence of a particular
compound. In this investigation, you will use
several indicators to test for the presence of
lipids, carbohydrates and proteins in various
foods.
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• Title
• Problem
• Hypothesis
• Independent variable
• Dependent variable

• The effect of _______ on _____.
• Using the indicators (listed below) which test
  for specific compounds. Which of the 4 major
  types of organic compounds are found in spinach?
  
• Iodine change color if
• Benedicts present in a
• Biuret particular compound
• Ifthenbecause
• Complete the rest of your Lab-write up on your
  own.

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• Independent variable
• Dependent variable
• Control
• Contants
• of Trials

• The indicators added to the samples
• - Iodine
• - Benedicts
• - Biuret
• The color change of the samples.
• The color of the samples before adding indicator
• Materials, amounts, equipment
• 1 for each indicator

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Data chart
Food Sample Lipid Starch Sugar Protein
Egg white
Corn Oil
Potato
Butter
Distilled Water
Apple Juice
Fish
Spinach
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Materials

• For each organic compound test you need
• 5 drops egg white
• 5 drops apple juice
• 5 drops corn oil
• 5 drops fish
• 5 drops of distilled water
• 5 drops butter
• 5 drops of potato
• 5 drops of spinach
• Starch test Iodine solution
• Sugar test Benedicts solution
• Protein Biuret solution

• 8 Test tubes
• Test tube holder
• Test tube rack
• Hot plate
• Brown paper towel
• Labeling tape

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Lipid Test

• 1. Divide a piece of brown paper towel into 8
  equal sections. In each section, write the name
  of one test substances, as shown.
• 2. In each section, place a small drop of the
  identified food onto the brown paper towel. With
  another paper towel, wipe off any excess pieces
  of food that may stick to the paper. Set aside
  for 10-15 minutes
• 3. Hold paper to light or window. If food sample
  produces a translucent or see-through spot, there
  is a presence of a LIPID.

1.Distilled Water 2.Egg White 3.Corn Oil 4.Potato
5. Butter 6.Apple Juice 7. Fish 8. Spinach
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Carbohydrate Test - Starch

• 1. Label test tubes distilled water, egg, oil,
  butter, apple juice, potato, spinach, fish
• 2. Add 5 drops of each food sample to its proper
  test tube.
• 3.Add 2-3 drops of iodine solution to each test
  tube and shake.
• Iodine will change color from yellow brown ?blue
  black in presence of STARCH.
• 4. Record data on table.
• 5. Wash test tubes thoroughly!

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Carbohydrate Test - Sugar

• 1. Set up hot water bath Fill half the beaker
  with tap water and heat to a gentle boil.
• 2. While water bath is heating, fill each cleaned
  test tube with 5 full drops of the appropriate
  food sample.
• 3. Add 2-3 drops of Benedicts solution and shake.
• 4. Place test tubes in hot water bath and heat
  for 3-5 minutes.
• 5. Caution Remove test tubes from water bath
  with test tube holder!
• When heated, Benedicts solution will change
  color from blue ? green, yellow, orange, or red
  in the presence of SUGAR.
• 6. Record any color changes on data table.
• 7. Wash test tubes thoroughly!

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Protein Test

• 1. Put 5 drops of appropriate food samples in
  each labeled test tube.
• 2. Add 2-3 drops of Biuret solution to each test
  tube and gently shake.
• Caution Biuret contains NaOH, a strong base. If
  you splash any on yourself, wash with water and
  notify your teacher immediately!
• Biuret changes color from light blue?blue-violet
  in the presence of PROTEIN.
• 3. Record any color change on data table.
• 4. Wash test tubes thoroughly!

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POST LAB QUESTIONS

• Which foods come from plants? What biomolecule is
  most common in these foods?
• Which foods come from animals? What biomolecule
  is most common in these foods?
• Does water contain any of the macromolecules that
  you tested for? Explain why water is used as a
  control.

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Fill out the following table by listing the foods
that you tested.
High in Carbohydrates High in Protein High in Lipids