Unit 1: Chemistry of Life, Part II:...

Biology H Name ________________________________________

2018 - 2019 Date ________________Block ________________

PACKET #2

Unit 1: Chemistry of Life, Part II: Biochemistry

Reading: BSCS Text Chapter 1.6 – 1.10

Learning Objectives:

Topic 3: Organic Molecules

11. Differentiate between organic and inorganic compounds (1.6).12. List the 6 most common elements found in living things: CHNOPS/SPONCH (p. 25)13. Define and relate the terms macromolecule, polymer, monomer, and polymerization (class)14. Describe and relate the terms: biosynthesis (dehydration synthesis), and decomposition (hydrolysis)(2.7)15. Describe (and identify a diagram of) monosaccharide, disaccharide, and polysaccharide and discuss theirsignificance in organisms (1.7).16. Describe (and identify a diagram of) the structure and importance of lipids - including phospholipids andcholesterol (1.8)17. Explain the difference in structure between unsaturated and saturated lipids, and explain why eating one type isbetter for your health than eating the other (1.8)18. Identify the functional groups and R group of an amino acid.19. Describe the four levels of structure in proteins, including how polypeptides form (1.9)20. Explain that different classes of proteins regulate and carry out the essential functions of life (1.9).21. Describe the structure of nucleic acids (1.10)22. Describe the importance of nucleic acids (1.11- 1.12)

Topic 4: Ecology Connection

Vocabulary (Topic 3): Organic molecule

Hydrocarbon Macromolecule Polymer Monomer Polymerization Dehydration synthesis

Hydrolysis Carbohydrate Monosaccharide

Disaccharide Polysaccharide Starch Glycogen Cellulose Lipids Hydrophobic Hydrophilic Phospholipids Cholesterol Steroids Saturated fat

Unsaturated fat Glycerol Fatty acid Protein Amino acid Polypeptide Peptide bond Hormone Antibody Structural protein

Enzyme

Primary, secondary, tertiary structure

Nucleic acid ATP Double helix Purine Pyrimidine

23. Describe the ecological relationships that exist between sea lions, pollock, and herring.24. Using your understanding of biomolecules, explain why sea lions might survive better on herring on pollock.

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Topic 5: Evolution Connection E – 8 Describe the process of chemical evolution; how do scientists think organic molecules arose? E – 9 Compare and contrast the atmosphere of Early Earth with the atmosphere on Earth today. E – 10 Describe the “RNA World” hypothesis. What evidence supports this idea? E – 11 Describe the heterotroph hypothesis (Oparin-‐Haldane hypothesis), and explain how this hypothesis

may be supported by (1) The Miller-‐Urey experiments (2) meteors (3) polymerization on clay (4) hydrothermal vents (5) catalytic RNA

Biological Molecules

Biological MoleculesWhat are the building blocks of life?

Why?From the smallest single-celled organism to the tallest tree, all life depends on the properties and reactions of four classes of organic (carbon-based) compounds—carbohydrates, lipids, proteins, and nucleic acids. These organic molecules are the building blocks of all living things, and are responsible for most of the structure and functions of the body, including energy storage, insulation, growth, repair, communica-tion, and transfer of hereditary information. Simple organic molecules can be joined together to form all the essential biological molecules needed for life.

Model 1 – Molecules of Life

Carbohydrates (monosaccharides)

Glucose Galactose Fructose

Lipids

Glycerol Fatty acids Triglyceride (fat or oil)

Proteins (amino acids)

Alanine Cysteine Amine group

Nucleic acids (nucleotides)

O

OH

HH

H

OH

OH

H OH

H

OH

O

OH

HH

OH

H

OH

H OH

H

OH

O

OH

H

OH

OH

H

H

OH OH

C

C

C

H

H

OH

H OH

H

H OH

C

O

(CH 2)12CH3OH

C

O

(CH 2)7CH=CH(CH 2)7CH3OH C

CH

H

H OC

O

CH3

OCO(CH 2)7CH=CH(CH 2)7CH3

CH

H OC

CH3

O

C

O

(CH 2)14CH3OH

C

R

H

N C

O

OH

H

HC

H

N C

O

OH

H

H

CH2SH

C

CH3

H

N C

O

OH

H

H

Proteins (amino acids)

Alanine Cysteine

Variable Rside chain

Carboxylicacid group

Aminegroup

NO

O

OH

OH

OH

O

P N

NN

NH2

OH

Variable R side chain

Carboxylicacid group

Nitrogen base

Phosphate group

Sugar

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POGIL™ Activities for High School Biology

1. Use Model 1 to show which atoms are present in each type of molecule by listing the symbol foreach atom included. Carbohydrate has been done for you.

a. Carbohydrate— C, H, O c. Amino acid—

b. Lipid— d. Nucleic acid—

2. Which type of molecule includes an example with a long-chain carbon backbone?

3. In the molecule referred to in the previous question, what is the dominant element attached tothe carbon backbone?

4. The fatty acid chain of the lipids is often referred to as a hydrocarbon chain. Discuss with yourgroup why the chain is given this name and write a one-sentence defi nition for a hydrocarbon.

5. Which molecule has a central carbon atom with four different components around it?

6. Which molecule has a sugar, nitrogenous base, and phosphate group?

7. Discuss with your group members some similarities among all four types of molecules. List asmany as you can.

8. What is the chemical formula of the fi rst carbohydrate molecule shown?

9. What three structural groups shown do all amino acids have in common?

10. There are 20 naturally-occurring amino acids, and each one only varies in the structure of theR side chain. Two amino acids are shown in Model 1. What are the R side chains in each?

Read This!During chemical reactions, the bonds in molecules are continually broken and reformed. To break a bond, energy must be absorbed. When bonds are formed, energy is released. If more energy is released than absorbed during a chemical change, the process can be used as a source of energy. A general rule for processes such as respiration is the more carbon atoms there are in a molecule, the more energy that molecule can provide to the organism when it is used as food.

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Biological Molecules

11. Using the information from above, is a carbohydrate or a lipid more likely to be a good source ofenergy for an organism?

Model 2 – Biochemical ReactionsA. B.

C

R

H

N C

O

OH

H

HC

R

H

N C

O

OH

H

H

C

R

H

N CH

H

O

C

R

H

NH C

O

OH

+

Amino acid 1 Amino acid 2

Dipeptide

+ H2O

O

OH

HH

H

OH

OH

H OH

H

OH

O

H

OH

OH

H

CH2OH

OH CH2OH

H

O

HH

H

OH

OH

H OH

H

OH

O

O

H

OH

OH

H

CH2OH

CH2OH

H

+

Glucose Fructose

+ H2O

C.

C

O

(CH 2)14CH 3OH

C

CH

H

H OH

CH

H OC

CH3

O

OH

+

C

CH

H O

CH

H OC

CH3

O

OHH

(CH 2)14CH 3

O

Monoglyceride

Fatty acid

Diglyceride

+ H2O

Glucose

Sucrose

Dipeptide

Fatty acid

Diglyceride

Amino acid 1 Amino acid 2

Monoglyceride

Fructose

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POGIL™ Activities for High School Biology

12. What are the reactants of reaction A?

13. What are the products of reaction A?

14. Each of the reactants in reaction A is a single sugar molecule, also called a monosaccharide. Whatprefi x before saccharide would you use to describe sucrose?

15. What are the reactants of reaction B?

16. When the two molecules in reaction B are joined together, what other two molecules are pro-duced?

17. What product do all three reactions in Model 2 have in common?

Read This!When sugars are joined together the new bond that forms is a glycosidic bond. When amino acids are joined the new bond that forms is a peptide bond. When fatty acids are joined to a glycerol the bond that holds them is an ester bond.

18. On the diagrams in Model 2, circle and label the glycosidic, peptide, and ester bonds.

19. These reactions are all referred to as dehydration synthesis or condensation reactions. With yourgroup develop an explanation for why these terms are used to describe these reactions.

20. These reactions can also be reversed, breaking the large molecule into its individual molecules.What substance would need to be added in order to reverse the reaction?

21. Lysis means to split or separate. What prefi x would you add to lysis to mean separate or splitusing water?

22. Using your answers to the previous two questions, what word is used to describe the reaction thatuses water to break apart a large molecule?

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Extension Questions23. Metabolism is the collective term used to describe all the chemical reactions taking place inside

living organisms. Why is water so important for metabolic reactions?

24. We store excess food in our body either in the form of carbohydrates (in muscles and the liver)or as fat (adipose tissue). When our body needs additional energy it uses the carbohydrate sourcefirst as a source of “quick” energy, then the fat. Why do you think carbohydrates are used as asource of quick energy rather than fat? Use complete sentences and scientific terminology in yourresponse.

25. Look at the two types of fatty acids below, saturated and unsaturated. What is the differencebetween the two?

C

C

C

C

C

H H

H H

H H

HH

HH

H

OH O

C

C

C

C

C

H

H

H H

HH

HH

H

OH O

Saturated Fatty Acid Unsaturated Fatty Acid

26. Saturated fats are solid fats, like the animal fats lard and butter, whereas unsaturated fats are morefluid and form oils, such as vegetable oil. Trans fats are plant oils that are artificially solidifiedto make them suitable for baking purposes. In recent years trans fats have been associated withnegative health issues and are not as widely used. Explain in simple molecular terms what wouldhave to be done to a plant oil to transform it to a trans fat.

Saturated Fatty Acid Unsaturated Fatty Acid

Homework: Each person should bring in one food/box/wrapper with a nutrition label for our next activity.6

Macromolecules+Objec(ves"10","11"

Carbon+Compounds++• All"life"is"built"on"carbon"• 4"valence"electrons"• Forms"4"covalent"bonds!"• Lots"of"possibili(es"

• In"Cells"• ~"72%"H2O"• ~"25%"Carbon,based"Biomolecules*(macromolecules)*• Carbohydrates"• Lipids"• Proteins"• Nucleic"Acids"

• ~"3%"salts"(Na,"K,"Ca)"

Carbon+Compound+Shapes++

Made"possible"by"carbon"(and"these"molecules"only"have"C"and"H)"

Building+Biomolecules+• Biomolecules"are"BIG"• Aka"Macromolecules"

• Most"are"long"chains"of"repea(ng"subunits"• All"except"lipids"

• Smaller"organic"molecules"(monomers)"join"together"in"a"chain"to"form"polymers.*

• Linked"by"covalent"bonds"

Building+Biomolecules+• Dehydra(on"Synthesis"• Joins"monomers"by"removing"water"• Requires"energy"and"enzymes"

Dehydra(on"Synthesis"(Condensa(on"Reac(on)"

Synthesis"means"“to"build”"

Digesting+Biomolecules+• Hydrolysis"• Reverse"of"dehydra(on"synthesis"• H2O"added"to"break"monomers"apart"

“Hydro”"means"“water”"

“Lysis”"means"“cu^ng”"

Hydrolysis"(Diges(on"Reac(on)"

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Carbohydrates+Monomer* Dimer*(2*monomers)* Polymer*

Monosaccharide"(simple"sugar)"

Disaccharide" Polysaccharide""

Proteins+Monomer* Dimer* Polymer*

Amino"Acid" Dipep(de" Polypep(de"

Polypep(de"structure"

Nucleic+Acids+Monomer* Polymer*

Nucleo(de" Nucleic"Acid"

• RNA"• 1"long"chain"of"nucleo(des"• Linked"by"dehydra(on"synthesis"

• DNA,"the"“double"helix”"• 2"long"chains"of"nucleo(des"twisted"together"

Lipids+• Not"a"Polymer"(no"repea(ng"subunits)"• 1"glycerol"• 3"fa_y"acid"chains"• Linked"by"dehydra(on"synthesis"

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Analyzing Nutrition Labels

Metabolism is the sum of chemical reactions in your body. Your body uses chemical reactions to break down food, release energy, build new cell parts, produce heat, and much more. Foods you eat include macromolecules (large molecules) that your digestive system can break down for energy. These molecules include carbohydrates, protein, and fats. (Note that these are 3 of the four major types of biomolecules. Nucleic acids are the 4th type, but we do not get much energy from them.)

Activity 1: Calculating Kilocalories

You are going to figure out the amount of kilocalories (energy) in each of the foods you analyze. Use the kilocalorie chart below to make your calculations. Remember that foods with more kilocalories contain more energy.

Kcal per gram

Fat 9

Protein 4

Carbs 4

Name of food # Kcal from fat # Kcal from protein # Kcal from carbohydrates

Activity 2: Basal Metabolic Rate (BMR) Basal metabolic rate is the amount of energy (in the form of calories) the body needs in order to function while resting for 24 hours. BMR depends on several factors including age, sex, and height. It is possible to estimate your BMR using the formula below:

For men: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5 �� For women: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161

Calculate the BMR for the following people: 1. A 20-year-old woman who is 175 cm tall and weighs 72 kg.

2. A 20-year-old man who is 175 cm tall and weighs 72 kg.

3. A 40-‐year-‐old woman who is 175 cm tall and weighs 72 kg.

Calculate your BMR.

*Note: food labels use the word “calories” to make things sound simple. Really, labels list“kilocalories” in the food.

1 ft = 30.5 cm 1 lb = 0.45 kg

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Activity 3: Activity Energy

BMR is the amount of energy you use without doing any physical activity. To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:

•. If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2 •. If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375 •. If you are moderately active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55 •. If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725 •. If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9

1. Calculate the kilocalories you use everyday (your BMR + Kcal for daily activities)

2. How many kilocalories would you use everyday if you were alumberjack (extra active)?

Activity 4: Kilocalories and Food Groups

Answer the following questions in complete sentences. 1. List 3 foods people eat even though they provide very little energy.

Why do you think people eat these foods?

2. Refer back to the foods you analyzed in Activity 1. How many servingsof your foods would you need to eat per day to meet your energyneeds? Explain your answer.

Homework Look at the nutrition label to the right. Type and submit answers to ONE of the following questions. (Remember the writing guide!)

1. Describe the carbohydrate content of this food.• List the categories of carbohydrates present.• What specific molecules are likely present in the 41 grams

of “Total Carbohydrate”? (Name several.)• From which ingredients does each molecule come?

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Nucleic Acids

monom

er

_______, _______, _______, _______

Elements alw

ays present

___________, _____________

examples

Proteins

monom

er

_______, _______, _______, _______,

and sometim

es _________ Elem

ents present

__________________________

__________________________

__________________________

__________________________

examples

polymer

Carbohydrates

Organic M

olecules Elem

ents always present: _______, ______

Elements that m

ay be present:

_______, _______, _______, _______

monom

er

_______, _______, _______

In 1:2:1 ratio Elem

ents always present

examples

__________________________

__________________________

__________________________

Lipids Nonpolar m

olecules

_______, _______, _______

Elements alw

ays present

__________________________

__________________________

__________________________

__________________________

examples

A major com

ponent.

Straight chain Solid at room

temp.

Bends/ kinks Liquid at room

temp

Objectives 13 -‐ 15: In Class

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Sucrose

Glucose Fructose

Carbohydrates Proteins

Organic Molecules

Nucleic acids

Maltose

Disaccharides

Monosaccharides

Polysaccharides

Starch Cellulose Glycogen

(100’s of monom

ers) OR

Polypeptide

Amino acid

Triglyceride

Phospholipid

Fatty acids

Saturated Unsaturated

Lipids

Steroid structures

Objectives 13 -‐ 15: In Class

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Biology H

Survivor: Tropical Island

Introduction

Congratulations! You have been selected to participate in the reality TV show “Survivor.: Tropical Island.” The producers have chosen biology students throughout the United States to participate because the participants must use their biology knowledge to prepare for and succeed in the event.

Your experience on the island will be as follows: ● You will live on a deserted tropical island for four months.● You will have unlimited access to clean drinking water.● You will choose two foods to bring with you and you can have and eat as much of those

foods as you want.

Your Tasks

The question you are investigating in this project is as follows: Which two food items would help a person maintain their health on a deserted island?

Step 1: Do an initial brainstorm with your group. Write down the foods you are considering having on the island (it can be more than two at this point):

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Structure of Presentation

Your presentation will be structured in the following way.

You must have a hypothesis written in the following format: “If we bring ________ (food items), then _______________________ (write a prediction about how the food will affect your health), because ________________________________________ (state the evidence that supports it).

In your presentation you will start with your hypothesis and then go over three pieces of evidence to support the hypothesis. For each piece of evidence you will need to explain your reasoning for the evidence. In other words, why is this important? The diagram below describes this outline.

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Step 2: Do research.

Table I. Micronutrients Vitamin/Mineral

What does this nutrient do for you?

What foods have this nutrient?

What happens if you’re deficient in it?

Vitamin A

Vitamin B6

Vitamin D

Vitamin C

Iron

Calcium

Magnesium

Zinc

Write your sources for the information in Table I:

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Table II. Macronutrients

Macronutrient What does this nutrient do for you?

What are good food sources of this nutrient?

What happens when a person becomes deficient

in this nutrient??

Protein

Carbohydrates

Lipids

Write your sources for the information in Table II:

Step 3: Decide on your foods. Given your background research in Tables I and II, decide which two foods you want to bring with you to the island. Provide a breakdown of the food item and the nutrients it contains.

Table III. Food Items to Bring to the Island

Food Item Which nutrients are in this food? Sources

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Do the two food items in Table III provide enough nutrients for you to survive? ______ (yes or no). If yes, use the evidence from Table III to support this claim. If not, go back and reconsider your food options. Remember, this is no “right” or “wrong” answer. You just need to support what you are saying with evidence.

Step 4. Write your hypothesis: A hypothesis is often written as an “If... , then…, because…”statement. Fill in the blanks below to write your hypothesis for this project.

If we bring ____________________________ and ___________________________ to the island, these food items

will help us survive because ____________________________________________________________________________

____________________________________________________________________________________________________________

Step 5. Create a presentation for the class. The goal of your presentation is to state your hypothesis and convince the class that your hypothesis is correct by providing strong evidence. The presentation can be in a Google Slides, but it can also be something else like a video/movie or a Prezi (or something else). Your presentation should be 6-8 minutes long and it should answer the project question: Which two food items would help a person maintain health on a deserted island?

Presentation Outline:

● Your Hypothesis● The first reason your food items are a good choice. Provide background research

supporting it.● The second reason your food items are a good choice. Provide background research

supporting it.● The third reason your food items are a good choice. Provide background research

supporting it.● What was the runner up food item that you chose not to take? Explain why.● Caveats: Your food items will still probably not provide everything you need, or it might

provide too much of something. What is a possible negative effect? Provide researchcitations in support of what you write.

● Your presentation should communicate an understanding of the following concepts:Fats, protein, carbohydrates, essential vs. non-essential amino acids, cholesterol(LDL and HDL), water-soluble vs. lipid soluble vitamins, and B vitamins. Your job isto weave those concepts into your reasons why you chose those food items. Your job isnot to just lecture on the purpose of fats, proteins, etc.

● Conclusion (re-stating your hypothesis and briefly summarizing evidence in support)

Note: Use information obtained from textbook readings, research, and nutrient testing lab. Be sure to cite any sources you use in your research during your talk.

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Survivor Rubric

Topic 10 points 8 points 7 points 5 points

Vocabulary All relevant concepts are communicated correctly and thoroughly

80% of all relevant concepts are communicated correctly

70% of all relevant concepts are communicated correctly

50% or less of relevant terms are communicated correctly

Support of Hypothesis

All background information is cited and is thoroughly convincing in support of the hypothesis

Most background information is cited and is mostly convincing in support of the hypothesis

More than half of the background information is cited, and somewhat supports the hypothesis

Less than half of the background information is cited, and largely does not support the hypothesis

Understanding Demonstrates thorough understanding of material.

Demonstrates good understanding of material.

Demonstrates satisfactory understanding of material.

Understanding of the material needs improvement.

Style and Spelling

Presentation is highly attractive with excellent use of images and has no spelling errors

Presentation is attractive with good use of images and has few spelling errors.

Presentation is satisfactorily attractive with use of images and has moderate errors

Presentation is not attractive and has too many spelling errors.

Group work All group members are highly enthusiastic and effective in presentation

Most group members are highly enthusiastic and effective in presentation

Some group members are highly enthusiastic and effective in presentation

No group members are highly enthusiastic and effective in presentation

Group names:______________________________________________________________________________________________

Evaluator(s):_______________________________________________________________________________________________

Score: __________ / 50 Suggestion(s) for improvement:

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Review Questions: Chemistry of Life, Part II

1. Identify the following molecules by both name and category (carbohydrates, protein, lipid, ornucleic acid).

2. Complete the following chart, comparing different polysaccharides.

Part II: Match each question to the correct biomolecule(s). Answers may be reused, and many questions will have multiple answers.

A. CarbohydratesB. LipidsC. Proteins D. Nucleic AcidsE. None of these

1. Biomolecules the human body can use for energy. __________________

2. Contains only carbon, hydrogen, and oxygen. __________________

a. Contains approximately equal numbers of oxygen and carbon. __________________

3. Carries encoded information. __________________

4. Polymer of amino acids. __________________

5. Polymer of monosaccharides. __________________

Review Questions: Chemistry of Life Part II

1. Identify the following molecules by both name and category (carbohydrate, lipid, or protein).

2. Order the following from small to big: electron, insulin molecule, cell, water molecule, oxygen atom

3. Complete the following chart, comparing different polysaccharidesMade by plants or animals?

Use for organism thatmakes the molecule

Can humans hydrolyze(degrade) it?

StarchCelluloseGlycogen

4. What hormone increases glycogen levels (and therefore decreases blood glucose levels)? _________ Where is this hormone made? __________ What hormone decreases glycogen levels (and thereforeincreases blood glucose levels)? ___________ Where is this hormone made? ____________

5. The following set of questions refers to the molecule below:

a. What type of molecule is pictured above? ______________b. What special type of covalent bond links its monomers together? ___________c. What is the monomer from which this polymer is synthesized? ____________

Daley Biology H 2013-2014

11

!





Use for organism that makes the molecule

Can humans hydrolyze (degrade) it?






11

!

19

6. Hydrophobic. __________________

7. Hydrophilic. __________________

8. Forms by dehydration synthesis. __________________

9. Contains nitrogen. __________________

10. Some examples contain carbon, but no hydrogen. __________________

11. ATP is an example. __________________

12. Monomers are joined by peptide bonds. __________________

13. Important examples include enzymes, hormones, antibodies. __________________

13. 14.

15. 16.

17. 18.

19. 20.

20

21. 22.

23.

Part III: Building/Breaking Down Polymers 1. The following set of questions refers to the diagram below.

___________________ + ______ à ___________ + ____________ a. On the lines below the diagram, name the molecules shown in the chemical

reaction.b. What is this chemical reaction called? _________________________c. Will water be formed or used in this reaction? _________________________

2. The following set of questions refers to the molecule below.

+ à ______________________ + __________

A. Fill in the structural formulas to complete the chemical equation on the lines above.

B. What monomers are involved in this reaction? _________________________

C. What special type of covalent bond will join these two monomers?

_________________________

D. What is this reaction called? _________________________

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A. What type of molecule is pictured above?

B. What is the monomer from which this polymer is synthesized?

C. Will water be formed or used if this polymer is degraded into monomers?

D. How many molecules of water will be formed or used?





Use for organism thatmakes the molecule

Can humans hydrolyze(degrade) it?






11

!

22

“Mystery in Alaska” by Dinan, Stabler, & Larson

byFrank J. Dinan, Thomas R. Stabler, and Renee A. LarsonDepartment of Chemistry and BiochemistryCanisius College, Bu! alo, NY

Part I – West vs. EastStudies conducted by the Alaska Fisheries Science Center of the National Marine Mammal Laboratory have established that Steller sea lions have been disappearing at an alarming rate in Alaskan waters. Since the !"#$s, these marine mammals have experienced a severe overall decrease in population, but the decrease has not been uniform. % e region from the Prince William Sound through the Aleutian Islands has observed an &'–"$( decrease in the abundance of these creatures; this region contains the Western stock of Steller sea lions, as illustrated in Figure !. % e Eastern stock, also seen in Figure !, is located on the southeast coast of Alaska and its Steller sea lion population is increasing modestly (Figure )).

Figure 1. Distribution

Mystery in Alaska: Why Have All the Sea Lions Gone?

Credits: Figure ! courtesy of the Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA). Photo of Stellar sea lions in Resurrection Bay by Frank Kovalchek, Creative Commons Attribution 2.0 License.

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Figure 2. Steller Sea Lion Populations

Estimated numbers of Steller sea lions (all ages) in Alaska from 1956 to 2000 (from Trites & Larkin, 1996; A.W. Trites, unpublished data). Figure used with permission of the North Pacifi c Universities Marine Mammal Research Consortium.

% ere is particular concern regarding the Western stock of sea lion pups. Most of these juveniles don’t survive more than three years and therefore many do not reach sexual maturity, which occurs in males between * to & years of age and in females at an average age of +., years (Pilcher, !"&!). Because of their small size, the sea lion pups are more vulnerable to changes in their environment and are less able to adapt to these changes. While they have higher energy needs for growth and development, the pups are inexperienced hunters, ine- cient at catching prey, and largely dependent on their mothers for survival.

Questions!. List several possible reasons for the decline of the Steller sea lion population.

). Can any of your reasons explain why the Western sea lion stock is decreasing and the Eastern stock is modestly increasing? If so, how?

ReferencesPilcher, K.W., and D.G. Calkins. !&"!. Reproductive biology of Steller sea lions in the Gulf of Alaska.

Journal of Mammalogy '$,–""' :)*(),.Trites, A.W., and P.A. Larkin. ,""!. Changes in the abundance of Steller sea lions (Eumetopias jubatus) in

Alaska from ,'"! to )""!: How many were there? Aquatic Mammals ,,!–*'! ,*.)). http://www.marinemammal.org/pdfs/TritesLarkin#""!-abundance.pdf

24

http://www.marinemammal.org/pdfs/TritesLarkin1996-abundance.pdf


Part II –Pollock vs. HerringSteller sea lions are powerful predators, feeding on almost any smaller fi sh found in their habitat. However, two fi sh comprise a majority of the sea lions’ diet: pollock and herring. Herring are small schooling fi sh that can be fed upon in large numbers. Contrastingly, pollock are larger, more solitary, and di- cult for the sea lions to catch and digest.

In !"#$, the Federal government, prompted by environmental groups that argued that the pollock population was declining in western Alaskan waters, introduced a ban on the commercial fi shing of pollock from the southwestern coast of Alaska through the Aleutian Islands. % is ban altered the western waters’ ecosystem, but left that of the waters along the southeast Alaskan coast largely unchanged. While fi sh populations in the southeast remained unchanged, relative fi sh populations in the southwest fl ip-fl opped, with herring becoming less plentiful and pollock more abundant. (A portion of the fi sh community was salmon, and this remained unchanged with the change in fi shing regulations in both the southwest and southeast.)

As the ecosystem in southwest Alaskan waters changed, the population of the Western stock of Steller sea lions also changed. A census of the populations of pollock, herring, and the Western stock of Steller sea lions in southwest Alaska disclosed striking trends, which are illustrated in Figure *. It was also observed that the Western stock exhibited a far higher pup fatality rate than that observed in the Eastern stock (Rosen, )$$$).

Steller sea lions give birth to a single pup. % e age of weaning for pups is variable, ranging from one to three years. While the pups suckle, they do not hunt and are dependent on their mothers for food (Alaska, )$$#).

% e data in Figure * show the trends in the relative numbers of pollock, herring, and sea lions (% orne, )$$").

Figure 3. Population Trends

Graph based on based on ! orne, 2009.

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Part III – Diet vs. Energy RequirementsAn experiment was conducted at the Vancouver Aquarium Marine Science Centre to compare the relative e. ects of eating pollock and herring on Steller sea lions (Alaska Fisheries Science Center, !""+). Releasing live, swimming prey for sea lions to chase and capture in two very large tanks simulated the natural habitat of the Steller sea lions. % e fi rst group of sea lions was placed in a tank where they preyed upon herring as their only food source. A second sea lion group preyed exclusively on pollock in an otherwise comparable second tank. % e sea lions were allowed to eat as much of each of these types of fi sh as they desired. % ose fed herring all gained weight during the course of the experiment while those consuming exclusively pollock all lost weight.

% is experiment was then extended for the second group. % is group’s diet was switched so that they ate strictly herring rather than pollock. Under these conditions, the sea lions reversed their weight loss and experienced a steady weight gain. It was also noted that sea lion pups exhibited the most dramatic weight losses and gains during each of these experiments.

% e researchers compared the amount of energy available to the Steller sea lions when eating pollock to that available when they fed on herring. Pollock is a lean, low fat fi sh; it contains !( fat and )$( protein and #"( carbohydrate. Herring is a fatty fi sh; it contains !$( fat, !"( protein, and #!( carbohydrate (Donnelly, )$$*). It was also found that the larger pollock is a more di- cult fi sh for the sea lions to digest than the smaller herring.

% is experiment highlighted the importance of meeting energy requirements for marine mammals to live healthy lives. % ere are three general types of foods from which sea lions obtain energy: fats, carbohydrates, and proteins. Fats contain " calories per gram while proteins and carbohydrates a. ord only + calories per gram. To thrive, any species must consume food that provides enough net energy to sustain a healthy body.

Calculations!. Calculate the number of calories a sea lion would consume when eating !$$ grams each of pollock and

herring. Base your calculations on the fat, carbohydrate, and protein content of each of these fi sh.a. Total calories per !$$g of pollock = fat contribution + protein contribution + carbohydrate contributionb. Total calories per !$$g of herring = fat contribution + protein contribution + carbohydrate contribution

). Calculate the percent of calories obtained from fat, carbohydrate, and protein in both herring and pollock.

Questions!. Based on your calculations, which fi sh—pollock or herring—better meets the energy needs of the

Steller sea lions?

). Since the sea lions in each tank were allowed to eat unlimited amounts of prey, why did they lose weight when eating pollock? Why could they not just eat more pollock to maintain or increase their weight?

*. What is the signifi cance of the fact that the sea lion pups were a. ected more than the adults? Why werethe pups especially impacted? Explain your reasoning.

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Case copyright ©)$$" by the National Center for Case Study Teaching in Science. Originally published September )), )$$" at http://www.sciencecases.org/sea_lions/case!.asp. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this case study.

+. Using all of the information and the inferences you have drawn above, clearly explain why the Westernstock of the Steller sea lion population is decreasing while that of the Eastern stock has remained steady in the !"#$s and has increased modestly.

'. Propose a measure or measures that could be implemented to reverse the decline in the Western stock of Steller sea lions. Would you expect both support and opposition to the measure that you propose? If so, where would the opposition and support for your proposal come from?

ReferencesAlaska Fisheries Science Center. National Marine Mammal Laboratory: Marine Mammal Species. !""+.

http://www.afsc.noaa.gov/nmml/species/species_steller.php Last accessed: '/)$/$&.

Donnelly, C.P., A.W. Trites, and D.D. Kits. )$$*. Possible e. ects of pollock and herring on the growth and reproductive success of Steller sea lions. British Journal of Nutrition **: #!–&).

Fritz, L.W., and S. Hinckley. )$$'. A critical review of the regime shift—“junk-food”—nutritional stress hypothesis. Marine Mammal Science )!: +#,–'!&.

NoteWe have explored only one of the hypotheses that could account for the decline in the Western stock of Steller sea lions. Others exist that could also account for this decline. For example, a climate shift occurring in the region has also been proposed as a contributing cause (see Fritz and Hinkley, )$$'). Time considerations prevent us from exploring these alternative proposals.

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http://ublib.buffalo.edu/libraries/projects/cases/guidelines.html

http://www.afsc.noaa.gov/nmml/species/species_steller.php

http://www.sciencecases.org/sea_lions/case1.asp

http://ublib.buffalo.edu/libraries/projects/cases/case.html

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Name: __________________________________ Block: ___________ Date: _____________________ UNIT 1: THE CHEMISTRY OF LIFE

Evolution Connection #1: Abiogenesis

Learning Objectives E – 8 Describe the process of chemical evolution; how do scientists think organic molecules arose? E – 9 Compare and contrast the atmosphere of Early Earth with the atmosphere on Earth today. E – 10 Describe the “RNA World” hypothesis. What evidence supports this idea? E – 11 Describe the heterotroph hypothesis (Oparin-‐Haldane hypothesis), and explain how this hypothesis

may be supported by (1) The Miller-‐Urey experiments (2) meteors (3) polymerization on clay (4) hydrothermal vents (5) catalytic RNA

Key Terms Abiogenesis Primordial soup Miller-‐Urey experiment

Hydrothermal vents Heterotroph hypothesis RNA world hypothesis

Catalytic RNA

Unit 1 was all about chemicals. Believe it or not, even chemicals evolve! For this evolution connection, we will explore the origin and evolution of the first organic molecules. (Uh-‐whoa.)

You will watch 4 short videos and read a textbook section as you work on this packet. Links for the videos can be found on the class wiki. As you watch, you should answer the accompanying questions.

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Video 1: Abiogenesis http://www.bozemanscience.com/010-‐abiogenesis

1. What is abiogenesis?

2. Create a flow diagram to illustrate a sequence of steps that needed to occur for life to originate from non-‐life.

Non-‐life à __________________________ à ___________________________ à

___________________________ à Life

3. What is the significance of the Miller-‐Urey experiment? Which part of your flow chart (above) were Miller andUrey trying to address?

4. What do we mean when we say “primordial soup”?

5. Why is it so difficult to find evidence of the earliest living things?

http://www.bozemanscience.com/010-abiogenesis

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Video 2: The Miller-‐Urey Experiment http://highered.mheducation.com/sites/9834092339/student_view0/chapter26/animation_-‐_miller-‐urey_experiment.html

6. How was the atmosphere of Early Earth different from the atmosphere found on Earth today? (List moleculesthat were present and those that were absent.)

7. Briefly describe the Miller-‐Urey experiment. What did they do? What did they find?

Video 3: Hydrothermal vents http://www.pbslearningmedia.org/resource/tdc02.sci.ess.earthsys.deepseavents/deep-‐sea-‐vents-‐and-‐lifes-‐origins/

8. What makes the Mid Ocean Ridge System a possible location for the origin of life?

9. What is the black smoke that comes from vents and chimneys made of?

10. What challenges do organisms living in the deep ocean face?

http://highered.mheducation.com/sites/9834092339/student_view0/chapter26/animation_-_miller-urey_experiment.html

http://highered.mheducation.com/sites/9834092339/student_view0/chapter26/animation_-_miller-urey_experiment.html

http://www.pbslearningmedia.org/resource/tdc02.sci.ess.earthsys.deepseavents/deep-sea-vents-and-lifes-origins/

http://www.pbslearningmedia.org/resource/tdc02.sci.ess.earthsys.deepseavents/deep-sea-vents-and-lifes-origins/

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11. What types of organisms live there now? How do they get energy?

Video 4: RNA World http://www.pbslearningmedia.org/resource/nvra.sci.origin/the-‐rna-‐origin-‐of-‐life/

12. Discuss the limitations scientists encounter when using DNA to trace evolutionary history. How far back canthey go?

13. Explain the “chicken and egg” problem that evolutionary biologists face when studying origins of life.

14. What is the “RNA World” hypothesis?

15. What are some functions of RNA in our cells today?

Reading: Textbook section 17.4

16. Discuss Oparin and Haldane’s heterotroph hypothesis, which attempts to explain the origin of organicmolecules.

http://www.pbslearningmedia.org/resource/nvra.sci.origin/the-rna-origin-of-life/

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17. In the chart below, describe the following experiments and observations, and explain how they support theOparin-‐Haldane hypothesis.a. The Miller-‐Urey experiments, which attempted to simulate the prebiotic environment.b. Meteors contain some organic moleculesc. Polymerization reactions occur on clay mineral surfaces.d. Volcanic (hydrothermal) vents release hot gases from the Earth’s crust.e. Some RNA molecules are self-‐replicating.

Experiment/ Observation

Description/Explanation How this supports the Oparin-‐Haldane hypothesis

Miller-‐Urey

Meteors

Polymerization on clay surfaces

Hydrothermal (Volcanic) vents

Catalytic RNA

The following diagrams may help you with your notes. Cut and paste them into your notebook to help you answer objectives.

Objective 15:

Objective 16:

A triglyceride (fat)

Objective 14: Explain what an organic compound is and why they are important for life (1.6).

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Objective 15: Define and relate the terms macromolecule, polymer, monomer, and polymerization (1.6 and class notes).

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Objective 16: Describe and relate the terms: biosynthesis (dehydration synthesis), and decomposition (degradation hydrolysis) (2.7).

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Objective 17: Describe (and identify a diagram of) the structure and importance of carbohydrates – including monosaccharides, disaccharides, and polysaccharides (1.7).

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


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7 Objective 17:

Objective 18:

Objective 19:

Objective 18: Describe (and identify a diagram of) the structure and importance of lipids – including phospholipids and cholesterol (1.8).

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

zig zags are hydrocarbon chains

Objective 19: Explain the difference in structure between unsaturated and saturated lipids and explain why eating one type is better for your health than the eating the other (1.8).

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


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Objective 20: Describe the structure and importance of proteins, including how polypeptides are formed (1.9). _________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Objective 21: Describe the four levels of structure in a protein (1.9).

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


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Objective 20: Describe the structure and importance of proteins, including how polypeptides are formed (1.9). _________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Objective 21: Describe the four levels of structure in a protein (1.9).

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


4

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Objective 21:

Objective 22: Describe some ways that structure is important for function of a protein (1.9).

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Objective 23: Describe the structure and importance of nucleic acids (1.10).

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

A nucleotide contains: _______________________________________________________________________


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