Biology Ag – Unit 2Chemistry of Life

Terms to Know ______/22 Chemistry, pH & Water Notes ______/20 Bonding Basics _______/30 pH Lab ______/40 Water Lab _______/25 Macromolecules Chart _______/40 Macromolecules Sort _______/40 Enzymes Lab________/25

Unit Total ________/________

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Key Terms to Know:Organic:

Carbohydrate:

Protein:

Fat:

Nucleic Acid:

Lipid:

Catalyst:

Enzyme:

Solvent:

Solute:

Adhesion:

Cohesion:

Element:

Compound:

Molecule:

Macromolecule:

Activation Energy:

pH:

Hydrogen Bonds:

Homeostasis:

Polar:

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Chemistry, pH & Water Notes________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Name ___________________________________________________ Period ________

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Element # of Protons # of Electrons # of Valence Electrons # of Electrons to FillOuter Shell

Carbon

Hydrogen

Nitrogen

Oxygen

Phosphorus

Sodium

Sulfur

Chlorine

Follow your teacher’s directions to complete each covalent bond. Draw the bond structure using symbols and lines. Use one line for each pair of electrons shared. WRITE the chemical formula for each molecule

(1) Hydrogen + Hydrogen (2) Hydrogen + Oxygen

(3) Chlorine + Chlorine (4) Oxygen + Oxygen

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Bonding Basics - Covalent Style

(5) Carbon + Oxygen (6) Carbon + Hydrogen

(7) Now draw the ionic bond between Chlorine and Sodium. This makes the molecule of table salt. They swap an electron.

In the section below you will calculate fill in the blanks by using the periodic table. Make sure you know how to calculate the atomic mass, know how to find the atomic number, and infer that all elements are NUETRAL

Carbon:

Symbol_____________ Atomic #__________ Atomic Mass__________

Protons_____________ Neutrons__________ Electrons____________

Oxygen:

Symbol_____________ Atomic #__________ Atomic Mass__________

Protons_____________ Neutrons__________ Electrons____________

Sodium:

Symbol_____________ Atomic #__________ Atomic Mass__________

Protons_____________ Neutrons__________ Electrons____________

Lead:

Symbol_____________ Atomic #__________ Atomic Mass__________

Protons_____________ Neutrons__________ Electrons____________

Question:

Find the element on the table that has the symbol AG (silver). It has an atomic mass of 108 and an atomic number of 47. How many neutrons does this element have?

How many electrons does it have in a neutral atom?

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Name ___________________________

Properties of Water LabStation 1: Diagram the structure of 2 water molecules bonded together. Label the bonds, charges, and atoms. Explain how water’s structure makes it polar.

Station 2: Float a small piece of aluminum foil on water. Gently place beads on the aluminum foil.

-How many can it hold? _________. -How do objects that are denser than water float?

-What property of water is allowing the foil to float?

Station 3: This time add a small amount of detergent to the water. Place a small piece of aluminum foil on water. Place beads on the aluminum foil now.

-How many can it hold? __________. -Detergent is non-polar. How does the detergent change the way the foil floats?

Station 4: Get a small plate or bowl and cover the bottom with water. Sprinkle pepper on the surface of the water. Touch a soapy cotton swab to the water. What happened? Why? Soap is hydrophobic. Describe what you think this means.

Station 5: How does pollution of our lakes and streams from stuff that is washed down our drains influence water striders and other organisms that float or walk on water?

Station 6: Take a penny and a dropper. Estimate how many drops of water you can get on top of the penny before it overflows __________. Now, add water drop by drop to the top of the penny and count how many drops it can hold before overflowing. -How many drops? __________. Explain what property of water allows this to happen.

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Station 7: Notice how easy it is to separate two dry glass slides.7a. Hold the flat surfaces of two dry slides together. Immerse one corner of the slides in water. Wait 1 minute and explain what happened.

-What property of water caused the change in the slides?

7b. Try to separate the two glass slides when they have water between them. Explain what happened.

-What property of water caused this change in the slides?

Station 8: Each graduated cylinder started with the same amount of water. The difference is the size of the paper towel. Record how much water is left in each graduated cylinder.

Small towel ____ Medium towel ____ Large towel ____-Describe what property of water caused the change in the graduated cylinders.

Station 9 & 10: Because of its high polarity, water is called the universal solvent. A solvent is a substance that dissolves, or breaks apart, another substance (known as a solute). A general rule that determines whether a substance will dissolve in a solvent depends upon its polarity. Polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes. In this activity, you will compare the ability of water, alcohol, and vegetable oil to dissolve certain solids. CAUTION: Rubbing alcohol is flammable, an eye irritant, and has fumes. Wear safety glasses and gloves for this station.

Procedure:1. Number your test tubes 1-9 on a piece of scratch paper.2. Pour 10 mL of water into test tubes 1, 2, and 3.3. Pour 10 mL of rubbing alcohol in test tubes, 4, 5, and 6.4. Pour 10 mL of vegetable oil in test tubes 7, 8, and 9.5. Place a teaspoon of sugar in test tubes 1, 4, and 7.6. Place a teaspoon of salt in test tubes 2, 5, and 8.7. Place a small amount of margarine in test tubes 3, 6, and 9.8. Cover each test tube with your thumb and shake to mix.9. Observe your results and fill in the data table.10. Wash all of your test tubes with soap and water. Place them upside down in a test tube rack to dry.

Substance Water Rubbing Alcohol Vegetable Oil KeySugar +++dissolves ~100%

++ or + partial dissolves0 did not dissolve

Salt

Margarine

What general rule determines whether a solute will dissolve in a solvent?

From this experiment, would you conclude that sugar is polar or non-polar? Explain.

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Station 11: Using the pH strips, test the pH of each of the 3 clear liquids. Label below which liquid is water, vinegar (an acid), and ammonia (a base).

A. _______________ B. ________________ C. _______________

Describe how you figured out which liquid was in each container.

Station 12 & 13: Water has a high specific heat which means that it takes a lot of energy to change its temperature a small amount. Because of this, water resists temperature change. This is one property of water that helps us maintain a constant body temperature.

Proceudure:1. Add 30 mL of water to beaker A and 30 mL alcohol to beaker B.2. Record the temperature of both liquids.3. Place both beakers on the hot plate at the same time. Heat them for one minute.4. Remove the beakers using your beaker tongs and oven mitt. The beakers will be hot.5. Immediately record the temperature of both liquids.6. Let both liquids cool for 2 minutes and then record their temperatures.

Before Hot Plate After 1 minute on heat After cooling 2 minutesTemperature of WaterTemperature of Alcohol

Which liquid had the smallest change in temperature?

If you were to let these two liquids boil, which liquid would boil at a higher temperature. Explain your reasoning.

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Name:__________________ Testing pH Lab

Background: A liquid may be an acid, base, or neutral. The degree of acidity or basicity can be measured by using the pH scale. The scale is divided into three areas: Acid (readings below 7), neutral (reading of 7), and basic (readings above 7). Each division either increases or decreases the pH of a substance 10 times. For example, the pH of 5 is ten times more acidic than a pH of 6. Water has a pH of 7 but when it mixes with air the suspended materials will either raise or lower its pH. Acid Rain is an example of this type of reaction. Universal indicator paper changes depending on the pH of the solution being tested. Many substances around your home are acids with a low pH. Others are bases and have a high pH. Purpose: To determine the pH of some common solutionsMaterials- 50 ml beaker (#) - tweezers- Various common solutions - pH indicator paper and chart

Procedure1) Obtain a test tube rack containing several test tubes of various common solutions.2) Before testing each known solution, hypothesize about the pH of each of the known solutions. Use your previous knowledge of the solutions and knowledge of pH to create your hypothesis. Record your hypothesis in Table 1. (You will have to create a table with the appropriate number of rows. Use the column headings shown in Table 1 below)

Table 1Solution Hypothesis of pH pH Acid Base Neutral

3) Dip the tip of a strip of pH indicator paper into each beaker to test the pH of each known solution as shown in the diagram to the right. Use a different strip of pH indicator paper for each solution.Caution: Do not come in contact with any of the solutions. If contact is made, wash immediately with water and inform your teacher.4) Use the color scale on the indicator paper package to estimate the pH of each solution. If the color does not match any color on the indicator package exactly, estimate the pH (ex: 8.3 or 5.6). Record the pH of the known solutions in Table 1.5) Once the pH has been recorded, determine if each solution was an acid, a base, or neutral. Check the appropriate column. 6) Once all the solutions have been tested, use the pH scale below and put the known solutions in their appropriate place. The pH scale ranges from 0 (very acidic) to 14 (very basic), with 7 (neutral) in the center. Place the names of the solutions on the pH scale according to your results.

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7) Use red cabbage juice as a pH indicator to test the solutions that you tested earlier. See your teacher for details on this procedure.

Name:_____________________________________

Discussion: Answer the following questions

1) Was the pH of any of the solutions significantly different than what you hypothesized? Explain

2) What is the pH range of the solutions you tested? Are any of the solutions very acidic or very basic?

3) What does pH measure?

4) Compare the hydrogen ion concentration in vinegar to window cleaner.

5) Is pH an absolute or a relative measure? Explain

6) Word Origins. The p in pH stands for the German word Potenz, which means “power” or “potential”. The H represents the hydrogen ions (H+). How are these related to the definition of pH?

7) Describe the relationship between the hydrogen ions (H+) and pH. How is pH related to a solution’s acidity?

8) Do you notice anything about the solutions on the pH scale, their pH, and their location on the pH scale?

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9) Is the red cabbage juice as accurate as the pH indicator paper? Explain.

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Name:_______________________________

PINEAPPLE ENZYMES & JELL-O MOLDS

BACKGROUND: If you have ever made Jell-O by cooking the powder that comes in a box, you may have noticed the warning on the instructions that tell you not to add fresh or frozen pineapple to the gelatin. Have you ever wondered why?

Well, I have been telling you that most of cooking is really Kitchen Chemistry and this is another example. In this lab, you will be designing an experiment to test what is really happening when you add pineapple to gelatin. You know enough organic chemistry now to figure this out. First, you need a little background about gelatin… and it may be more than you ever wanted to know. Do you know what Jell-O is really made out of? Are you ready?...

WHAT IS JELL-O ANYWAY? That sweet colorful treat is actually made out of hides, bones, and inedible connecting tissue from animals butchered for meat. No? Yup!

All gelatin (including those made for photographic and laboratory use, as well as for desserts) is made out of discarded animal parts — the tough parts: bone and skin. And all these tough parts are made of proteins. In fact, the extracted gelatin is a protein. So, why do you think gelatin gets thick and jelly like when you cook it? (We’ll come back to that later.)

Gelatin can be extracted from any kind of animal, but cows are most common. If your Mom or Dad have ever made a batch of chicken soup from scratch, you've probably seen how it gets stiff and Jell-O like after it sits in the fridge… that's because boiling the chicken in water extracts the gelatin from the carcass (bones & cartilage), just like a miniature version of the commercial gelatin factories!

Commercial gelatin making starts by grinding up bones. The crushed bones are then soaked in a strong base (high pH) to soften them, and then passed through progressively stronger acid (low pH) solutions, until the end result isn't recognizable as bones at all! Then the whole mess is boiled for hours to extract the gelatin… and this part really makes a stink! Finally, the gelatin layer is skimmed off the boiling pot, and dried into a powder. With added sugar, flavorings, and artificial color, it's ready to become a jiggly dessert!

And now that you know what Jell-O's made from, why don't you put some on the table tonight? Your guests will be delighted when you share your new knowledge with them in the middle of a luscious spoonful of dessert!

By the way, this whole process of extracting gelatin from bone was originally developed in 1845 by an engineer, Peter Cooper — the man who Cooper Union (a college in NYC) is named after. Some time later (1895), Pearl B. Wait, a cough syrup manufacturer, bought the patent from Peter Cooper and adapted Cooper's gelatin dessert into an entirely prepackaged form, which his wife, May David Wait, named "Jell-O." The rest is history...

Made from bone… made from protein… so it must be tough stuff! So why can’t you put fresh pineapple in it? Let’s learn a bit about pineapple. The pineapple plant (Ananas comosus) is a grass-like plant, that belongs to the bromeliad family. It is thought to have originated in Brazil. In the 1950s, pineapple became the United State’s second most important fruit and Hawaii led the world in both quantity and quality of pineapples. However, times have changed and now, all canned pineapple comes from overseas, largely from the Philippines.

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As with some other tropical fruits, the pineapple fruit contains an enzyme that breaks down, or digests, protein. This protease enzyme in pineapple is called bromelain, which is extracted and sold in such products as Schilling's Meat Tenderizer. Papaya, another tropical fruit, also contains an enzyme, called papain, that digest protein. It can be found in Accent Meat Tenderizer.

PROCEDURE: In this lab, you will be given an array of materials and you will be asked to design your own experiment to test the effect of pineapple on gelatin. The goal is to understand what is actually going on in the pineapple-gelatin mix at a chemical level as well as understanding what affects the function of enzymes.

1.Materials: Fresh pineapple Canned pineapple Jell-o Beakers

Boiling & ice water Test tubes & rack Spoons, stirring rods Knife for cutting pineapple

2. Design a controlled experiment that shows the effect of raw pineapple on gelatin. Make sure your experiment description includes the following:

a. An hypothesis. Remember hypotheses are written as “If…then” statements.b. A detailed experimental design which will include:

1. The effect of fresh pineapple on gelatin.2. The effect of frozen pineapple on gelatin.3. The effect of canned pineapple on gelatin.4. The effect of freshly cooked pineapple on gelatin.5. A test to determine how gelatin behaves without any fruit additives.

c. A data table

3. Write up a detailed experimental plan on the accompanying sheet of paper.

4. You will be able to perform your experiment once you receive approval of your experimental design from your teacher.

EXPERIMENT RESEARCH PROPOSAL

Teacher Approval________________

1. Title:

2. Team Members (Maximum 3):

3. Research Relationship (What is affecting what?)

4. Research Prediction (What results do you expect?)

__________________________________________________________________________________________________

________________________________________________________________________________________________

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5. Hypothesis (Be specific. Include a variable you are measuring. In an “If, then” form)

__________________________________________________________________________________________________

________________________________________________________________________________________________

6. Experimental Design (Describe your experimental procedures)

a.

b.

c.

d.

e.

f.

g.

7. Independent Variable:

8. Dependent Variable:

9. What other factors must be controlled?

10. Data Table (Create a table to collect your data in.)

11. Title of Data Table & Graph

12. Proposed Plan to Analyze Data (In what way will you compare these numbers after you collect them?)

13. Explain what results you would need to see in your data to support your hypothesis

14. Complete the experiment. Collect the data in your Data Table. Graph your results in the space below. Answer the Summary Questions.

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Name_____________________________ SUMMARY QUESTIONS

1. Clearly describe the results of your experiment. In which test tubes did the gelatin jell, which did not.

2. Clearly explain the results of your experiment. Why did some containers of gelatin jell, why did others not. Be specific!

3. What is the enzyme in your experiment?

4. What is the substrate in your experiment?

5. What is (are) the product(s) in your experiment?

6. What type of organic molecule is gelatin?

7. What type of organic molecule is the enzyme, bromelain?

8. Write a “word equation” to describe the chemical reaction that occurs when pineapple is mixed with the gelatin.

9. Is the reaction of bromelain and gelatin synthesis (building) or digestion (breakdown)?

10. Why were the results of the freshly cooked pineapple different than the results of the fresh, raw pineapple? Be specific! What happened to the enzyme?

11. What is meat tenderizer and what does it do? Be specific!

12. Explain what is meant by denaturing a protein.

13. Design an experiment you could do in science class to test at exactly what temperature the pineapple enzyme denatures (unfolds). Be specific!

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