Earth’s Environme

ntalSystem

‘Traces of Life’Macro Organic-Molecules Lab

Procedure:There are two parts to this lab.

Part 1:During this part of the procedure you will learn how to perform four different tests used to identify the presence of proteins, starch, simple sugars, and lipids. The presence of macro-molecules are evidence of life. Without these essential building blocks, life cannot exist.

Get one test tube. You will use this test tube for all of the indicator tests. Clean it thoroughly between each test.

Tests 1-4 can be completed in any order! Pick a station that is not crowded by other students.

How to perform indicator tests:When adding the indicators to each tube, be careful not to touch the side of the test tube with the eyedropper. Hold the dropper over the tube mouth and let the drops “free fall” into the tube. After adding the indicators, give each tube a gentle tap with your forefinger to mix.

Protein TestTest 1: Perform a protein identification test using Biuret’s solution

1. Add 5 drops of the known protein solution to the test tube2. Add 5 drops of Biuret solution to the tube3. Mix well4. Compare the results with the color of the negative Biuret’s solution5. Any color change from the blue color of the Biuret’s solution is an indication of the presence of proteins6. Record the results in your data table

Glucose (most common sugars) TestTest 2: Perform a simple sugar identification test using Benedict’s solution

1. Add 5 drops of the known sugar solution to the test tube.2. Add 5 drops of the Benedict’s solution to the test tube3. Mix well4. Place the test tube in the boiling water bath for 5 minutes5. Remove the test tube from the boiling water using a test tube clamp.6. Compare the results with the color of the negative Benedict’s solution.7. Any color change from the blue color of the Benedict’s solution is an indication of the presence of simple sugars.8. Record the results in your data table.

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Starch (complex carbohydrate) TestTest 3: Perform a starch identification test using Iodine solution.

1. Add 5 drops of the known starch solution to the test tube.2. Add 5 drops of the iodine solution to the test tube.3. Mix well.4. Compare the results with the color of the negative iodine solution.5. Any change from the brown color of the iodine solution is an indication of the presence of starch.6. Record the results in your data table.

Fats (Lipids) TestTest 4: Perform a lipid identification test using brown paper

1. Add a drop of the liquid oil to a piece of brown paper.2. Hold the paper up to a light.3. A transparent spot on the paper is an indication of the presence of a lipid.4. Add a drop of water to a piece of brown paper5. Hold the paper up to a light6. A wet but not transparent spot is a negative result and an indication of the absence of a lipid7. Record your results in your data table.

Part 2: During this part of the procedure you will use the knowledge gained from Part 1 to identify the organic compounds present in unknown solutions.

1. Get three test tubes. Place 5 drops of ONE unknown substance in each test tube.2. Perform the tests for organic compounds.3. Record your unknown letter and the results.4. Repeat with a second unknown

Data Table 1: Positive Test Color Proteins Lipids Starches Glucose

Distilled WaterCooking OilGelatin SolutionApple JuicePotato SolutionUnknown # 1Unknown #2

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Analysis Questions:1. Which solutions identify the presence of life? Explain

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2. What are some limitations in using the indicators to test for the presence of the various carbon-based molecules? Include at least 2 limitations_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Suppose Unknowns # 1 & 2 were taken from samples from the Mars Rover expedition. What does the presence of the macro organic-molecules (proteins, lipids, starches, and/or glucose) suggest? Explain what conclusion scientists could come to, based upon these hypothetical ‘findings’.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Conclusion:Develop a claim, evidence reasoning paragraph for each of your UNKNOWNS.

• Claim – Present what the unknowns are (lipids, starches, glucose, and/or proteins) • Evidence – How you know what the unknowns are (explain the tests performed)• Reasoning – Tie your evidence back to what you know about the various organic compounds (look at your notes). Give me at least two pieces of information about the structure or function of the carbon-based molecules present in your unknowns.

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Saltines, Saliva, & Starch Reaction

Background Information:Starch is a long polymer of glucose molecules. There are three forms of starch; amylose, amylopectin, and ‘animal’ starch (glycogen).

Amylose (with an ‘o’) is the form found in the saltines used for this experiment. Amylose is a linear chain of 200-2000 glucose subunits bonded together that form a long helical structure. Iodine molecules fit tightly inside the helix, and consequent changes in the electron configuration of the iodine molecules cause the starch/iodine complex to turn a blue-black color. This color change indicates the presence of the complex carbohydrate (a.k.a. starch). This color reaction is reversible and is specific to the helical forms of glucose polymers found in starch.

Amylase (with an ‘a’) is an enzyme found in saliva. Amylase is responsible for breaking down amylose into the individual glucose subunits. As amylose is broken apart and the remaining sections grow shorter, they can no longer accommodate the iodine molecules. At this point the color reaction no longer takes place and the iodine will remain the normal brownish color.

Preliminary Questions:1. What color would you expect to see if you place a drop of the iodine solution directly on

the cracker? Why? Defend your answer.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. What color would you expect to see if you used the iodine test on a cracker you have chewed up and spit out? Why? Defend your answer.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Try it! Chew up a cracker for a few minutes. Spit it into a Ziploc baggy. Test it with the iodine solution. What did you observe? Make a data table…keep chewing!!!________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Did you observe what you expected? Explain!!! ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Materials:Saltine crackers, Test tubes, small cups, water, droppers, graduated plastic pipette, iodine

Procedure:1. Spit into a cup. You must collect at least 5 mL (1 tsp) of saliva. 2. Break off two pieces of cracker (about the size of a small pea)3. Crush each piece of cracker into oblivion and place into two separate test tubes labeled

‘A’ and ‘B’ respectively.4. Add 5mL of water to tube ‘A’.5. Add 5mL of saliva to tube ‘B’.6. Mix each tube thoroughly and allow the mixture to sit at room temperature for at least

minutes.7. Add one drop of iodine to each mixture8. Record your observation (a.k.a. what color does it yield)

Making sense of it All:Notice that after placing a drop of iodine on the cracker, it turns a blue-black color (as expected). The reaction indicates the presence of starch, a complex carbohydrate.

After chewing the second cracker, you may have expected that the starch would be broken down into glucose. This would result in a negative iodine test (a.k.a. it would remain brown and not turn blue/black). Your methodology is sound, but because there is an abundance of starch in the cracker and not enough amylase in the saliva it tests positive for starch (blue/black). Basically, there was not enough saliva to break the starch down completely.

After pulverizing the tiny bit of cracker and submerging it in your saliva, you were able to observe the expected negative iodine test (brown color). This is because the cracker sample was small and amount of saliva (amylase) was more abundant. Therefore, the long helical starch structure was completely broken down into smaller glucose molecules.

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Thought Experiments:

Amylase is a protein that functions as a biological catalyst (enzyme). Therefore, its activity can be changed by some simple manipulations.

1. Suppose you were to vary the ratio of cracker to saliva. How do you suppose the enzyme concentration affects the enzyme as assessed by the iodine reaction?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Different people produce different amounts of amylase in their saliva. How do you suppose other students’ results compare to yours? How could you test your hypothesis?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Acid & Base LabObjective:

Acids and bases are very common. For example, limestone is made of a substance that is a base when it is dissolved in water. In this investigation you will use what you have learned about solutions, acids, and bases to test various household substances and place them in categories according to their pH values investigate the properties of common acids and bases.

Materials:12 well spot plate pH indicator strips

pH indicator color chartvarious common household substances

Procedure:1. In your spot plate there are twelve known solutions.2. Read the data table and predict the pH given what you know about acids & bases.3. Read the four pre lab questions & answer them in complete sentences.4. Take turns testing the solutions in the numbered plastic wells by dipping a pH strip into

the liquid for about 2 secs. Take the strip out and "read" the pH within 10 sec. by comparing the color of the strip to the pH color chart.

5. Record the pH on your data chart for each of the numbered solutions.6. Now determine if the solutions were acids (pH from 0 - 6), neutral (pH 7) or bases (pH

from 8 - 14) Record this information on your data chart beside each solution.7. Clean up your lab area completely.

Pre-Lab Questions:

1. What pH range would you expect food/drink products to be in? ____________________

2. What pH range would you expect cleaning products to be in? ______________________

3. Which of the 12 substances do you think will have the lowest pH? ________________

Why? _____________________________________________

4. Which of the 12 substances do you think will have the highest pH? _______________

Why? _______________________________________________

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Data Table:

Solution # PredictedpH

pH from test Acid or Base?

#1 Mountain Dew

#2 Shampoo

#3 Salt Water

#4 Sugar Water

#5 Dish Soap

#6 Vinegar

#7 Baking Powder

#8 Alka-Seltzer

#9 Ketchup

#10 Borax

#11 Tap Water

#12 Sour Candy

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Solution # PredictedpH

pH from test Acid or Base?

#13

#14

#15

#16

#17

#18

#19

#20

#21

#22

#23

#24

Post Lab Questions:

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1. To be an acid, the range of pH must be:_________________

2. To be a base, the range of pH must be:_________________

3. To be neutral, the pH must be: _____________

4. List the names of the substances you tested that are acids.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5. List the names of the substances you tested that are bases.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

6. List the names of the substances you tested that are neutral (neither acids nor bases).________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

7. List the substance/s that appear to be the strongest acids. ________________________________________________________________________

8. List the substance/s that appear to be the strongest bases. ________________________________________________________________________

9. Which of the results surprised you the most? Why?__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

10. Analyze What general conclusions can you draw about the hydrogen ion concentration in many acids and bases found in the home? Are the hydrogen ion concentrations very high or very low? How do you know?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

11. Antacid tablets react with stomach acid containing hydrochloric acid. What is this type of reaction called? What are the products of this type of reaction?

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12. Place each of the 12 substances tested on the pH scale below.

13. Complete the Venn Diagram.

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Conclusion

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Inquiry Activity • Paper and Pencil

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Chapter 3 Age the IslandsProblem What can an island’s location tell you about its age?

BackgroundVolcano FormationMost volcanoes form at or near the boundary of two tectonic plates (examples: Mount St. Helens, Mount Vesuvius). But some form in the middle of a plate over a hotspot—a relatively stationary area of Earth’s mantle that is unusually hot. Most hotspots are located under oceanic plates. The tremendous heat of the mantle causes small cracks to form in the overlying oceanic plate, as it moves over the hotspot. Magma then oozes through these cracks and out onto the sea floor, where it cools and forms a small dome. Repeated eruptions over hundreds of thousands of years deposit more magma on the dome, forming a volcano. When the volcano emerges above sea level, it forms an island.

Figure 1. Hotspot The diagram shows the formation of islands, as a tectonic plate passes, during a span of tens of millions of years, over a hotspot in Earth’s mantle. As the plate moves, it takes the cooling volcano with it, which erodes and shrinks over time.

Aging Volcanic IslandsThe plate containing the new island volcano continues to move, carrying the island away from the hotspot, which makes way for a new volcano to form. As the process repeats, an island chain forms. Most islands have one volcano. However, some islands have multiple peaks. Some island chains, such as the Hawaiian Islands, form in a simple arc. Other chains, such as the Galápagos Islands, formed by subduction of the Nazca Plate, being pulled down under the South American Plate. Those island chains are more clustered. Island chains all have one thing in common, however. The islands farthest from the hotspot are generally older and smaller, with rounded peaks and eroded slopes, while those closer to the hotspot are generally younger, taller, and steeper.

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ProcedureStep 1 Locate the Galápagos Islands and the Galápagos hotspot on your map. Mark

the hotspot location on your map and label it.

Step 2 Measure the distance of Santiago Island from the Galápagos hotspot. Using the map’s scale bar, convert your measurement to an actual distance in kilometers. Record this distance in the data table.

Step 3 Repeat Step 2 for the other islands.

Step 4 Compare the height and area of the islands, and the number of active volcanoes on each. Then, using this information, along with the relative distance of each island from the hotspot, rank the islands from oldest to youngest.

Location of the Galápagos Islands and Hotspot

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1. Use your observations to complete the data table below.

Data Table

Height (m) Area (km2) Active Volcanoes

Approx. Distance

From Hotspot (km)

Relative Age

(1 = oldest)

Santiago 907 585 0

San Cristóbal 896 547 0

Española 206 61 0

Floreana 640 168 0

Santa Cruz 864 979 0

Isabela 1,707 4,588 6

Fernandina 1,494 629 1

Marchena 343 115 0

Analyze and Conclude2. Analyze Data Which island in this group is the youngest? Which is the

oldest? Explain your reasoning.

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3. Infer Based on the positions of the islands relative to the Galápagos hotspot, in what direction is the Nazca Plate moving? What evidence did you use to infer this?

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4. Draw Conclusions Which island do you think is younger—Isabela or Fernandina? Explain your reasoning.

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5. Extension Imagine that ten million years from now someone visits and observes the Galápagos archipelago. Name the two islands they would be least likely to see. Then identify where the person in the future is most likely to find a new Galápagos island. Give at least one reason for each prediction.

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Inquiry Activity • Paper and Pencil

Chapter 3 Effects of CO2 on PlantsProblem Does increased atmospheric CO2 affect stomatal activity in plants?

BackgroundHow Plants Exchange Material with the AtmosphereDuring photosynthesis, plants take in CO2 and release oxygen through tiny pores called stomata located on the underside of leaves. These pores are also where the plant releases excess water vapor. When stomata open, carbon dioxide enters the plant, and oxygen and water vapor are released. When stomata close, gas exchange and water loss stop. This is a trade-of; a plant whose stoma are closed to conserve water cannot get needed CO2 while a plant whose stomata are wide open and taking in a lot of CO2 will lose more water.

Figure 1. Typically, when stomata are open, CO2 molecules flow in, and water vapor flows out.

Plants and CO2 LevelsScientists have shown conclusively that the dramatic rise in atmospheric CO2 concentration is linked to rising global temperatures. The concentration of CO2 in the atmosphere was 385 ppm in 2007, up 10% since 1985 (Keeling, et al., Carbon Dioxide Research Group, 2008. Though many people view climate change with alarm, some consider high atmospheric CO2 as beneficial, stating that the excess CO2 will increase rates of photosynthesis and cause plants and crops to grow larger and faster. Somehave even predicted that increased plant growth will remove enough excess CO2 to slow down global warming.

Elevated CO2 and Stomatal ActivityOne way to estimate CO2 uptake activity is by measuring stomatal width in leaves exposed to different levels of CO2. In this exercise, you will predict whether increased CO2 concentrations will affect the amount of stomatal opening in plants. You then will graph and analyze data showing stomatal sizes in plants exposed to different levels of atmospheric CO2.

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1. Predict the effect, if any, of elevated atmospheric CO2 on stomatal width.

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Data Table

CO2 Concentration(ppm)

Stomatal Aperture Width(μm)

0 2.63

385 2.21

800 1.67

2. Using data from the table above, draw a bar graph in the space below.

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Analyze and Conclude3. Analyze Data What happened to stomatal aperture width as CO2 levels increased?

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4. Interpret Graphs At what CO2 concentration was stomatal aperture width at its greatest? Lowest?

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5. Draw Conclusions Does the data suggest that stomata open wider or get narrower as CO2 levels rise? Do you think this benefits or harms the plant? What would happen to the relative amount of gas exchange and water loss in this situation? Explain your reasoning.

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6. Relate Cause and Effect Increased atmospheric CO2 is linked to warmer air temperatures. How might warming air affect water availability? How would the change in water availability affect plant growth in the long term?

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7. Extension Based on your observations and analysis of the data, predict how increased atmospheric CO2 levels might affect crop growth and agriculture in the future.

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Name:__________________ Period:___________

Who Moved The Beach?Positive and Negative Feedback Loops

Coastal Erosion Subject Review

The following reports and articles contain the information needed to complete this worksheet:

“Coastal Change Hazards” U.S.G.S. Web site beginning at:

http://coastal.er.usgs.gov/hurricanes/coastal-change/

http://coastal.er.usgs.gov/hurricanes/cch.php

http://coastal.er.usgs.gov/hurricanes/impact-scale/water-level.php

“Coastal Erosion: Where’s the Beach?” Bridge Data Tip at: http://www.vims.edu/bridge/archive0500.html

“Beaches on the Brink” CNNfyi.com article at http://archives.cnn.com/2000/fyi/news/09/20/coastal.erosion/index.html

“Presque Isle – Trail of Geology” (hard copies provided)

http://www.dcnr.state.pa.us/cs/groups/public/documents/document/dcnr_015911.pdf

Coastal Change Hazards

1. The __________ or __________ (if there is no dune present) are the “first line of defense” against coastal erosion from wind and waves.

2. __________ are composed primarily of sand and are the most dynamic land masses along the open-ocean coast.

3. The impact of a storm on a barrier island is dependent on storm characteristics and the __________ of the barrier island when the storm makes landfall.

4. The Coastal Change Hazard Scale categorizes net erosion during storms into __________ impact levels or ”regimes.”

5. In the __________ Regime, waves cross the base of dunes, causing erosion and semi-permanent changes.

6. In the __________ Regime, storm waves are high enough to completely submerge the island, allowing sand to be transported over a distance of one or more kilometers toward the mainland.

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7. In the __________ Regime, waves exceed the elevation of the dune or beach berm (if no dune is present), causing sand to be transported toward the mainland so the barrier island “migrates” landward.

8. In the __________ Regime, waves are confined to the beach. Sand may move offshore, but will be eventually returned so there is no net erosion.

Coastal Erosion

9. Beach sand originates mainly from __________, and also comes from __________, and from __________.

10. Coastal erosion is a natural process that removes sediment from shorelines. Another natural process that deposits sediment on shorelines is known as __________.

11. Sand is generally moved offshore by high-energy waves during __________ months, and is returned by gentle waves during __________ months.

12. Movement of sand parallel to the coast by wave action, wind, and currents is known as __________.

Beaches on the Brink

13. Sea walls, jetties, and bulkheads may contribute to erosion because ________________________________________.

14. When the Cape Hatteras lighthouse was constructed in 1870, it was __________ feet from the shore. By 1987, the lighthouse was __________ feet from the sea due to coastal erosion.

15. People have three choices when erosion poses a threat: __________, __________, or __________.

Presque Isle – Trails of Geology

16. Presque Isle is a _____________ ___________. (landform)

17. Presque Isle is related to the presence of a ridge of sediment called a _____________.

18. It consists of clasy, sand and gravel that was carried by huge bodies of slowly moving ice called ________________.

19. This glacier covered much of northern PA about ____________ to ____________ years ago.

20. ____________ and ______________ shaped loose sand into deposits into _______________ and _______________.

21. How deep is the water surrounding Presque Isle? _____________ ft.

22. Presque Isle is French for “_______________________________________”.

23. What has happened to PI four times since 1819? ______________________________________________________________________________________________________________________________________

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24. The history of growth and erosion of PI can be seen the pattern of ___________ ______________ the and ____________ and _____________ that commonly occupy the low areas between them.

25. Look at the geological profile provided on page 5. What is the significance of the geological evidence it provides? ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

26. ___________________ carries sand along beaches and from the beaches to the backshore and dunes.

27. The zig-zag path of the sand grains moving with the water is an example of ___________ transport.

28. _______________ currents wash the disturbed sand grains offshore or down current.

29. Most ____________ and ________________ are about 150-600 ft. from shore.

30. The tip of PI is known as _________ __________, were the newest beaches of PI exist.

31. List four methods ‘Man’ has attempted to preserve the current condition of PI. ______________________________________________________________________________________________________________________________________

32. A groin is a _________________________________________________________ ______________________________________________________________________________________________________________________________________

33. A sea wall is a ________________________________________________________ ______________________________________________________________________________________________________________________________________

34. Beach Nourishment is __________________________________________________ ______________________________________________________________________________________________________________________________________

35. Detached breakwaters are ______________________________________________ ______________________________________________________________________________________________________________________________________

36. Now that you know a bit more about the erosion management of PI, place several of the four erosion prevention management structures along the map of PI as you see fit. Explain the placement of each of the structures and provide a key.

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1. Draw arrows representing wind and current directions. Label each. 2. Explain how you selected the placement of each structure!!!

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