12a Cycling of Matter & Energy Flow - Health and Science ... · PDF file328 Cycling of Matter & Energy Flow – Eating for Energy, HASPI Medical Biology Lab 12 Name(s): Period: Date:

Cycling of Matter & Energy Flow – Eating for Energy, HASPI Medical Biology Lab 12 327

Name(s): Period: Date:

Cycling of Matter & Energy Flow - Eating For EnergyHASPI Medical Biology Lab 12 Background/Introduction Food Chains & Food Webs Organisms within an ecosystem interact with one another and the environment to acquire matter and energy. One of the primary ways in which organisms interact is consuming one another. Organisms within an ecosystem are separated into groups, called trophic levels, depending on how they obtain food. These organisms may be different depending on the type of biome and ecosystem in which they live. The following chart summarizes these trophic levels, and provides an example of organisms within each level for a forest biome. Trophic Level Description Forest Biome Example

Producer

Gain energy and matter through photosynthesis by converting solar

energy into chemical energy.

Includes algae, plants, and plant products (fruits, vegetables, nuts, seeds, etc.)

Grasses Berries & Flowers Seeds

Primary Consumer

Gain energy and matter by consuming producers. Primary consumers mainly

consume plants, and are also known as herbivores.

Includes insects, small rodents, deer, rabbits, porcupines, skunks, etc.

Insects Rodents Deer

Secondary Consumer

Gain energy and matter by consuming primary consumers. Secondary

consumers that mainly consume other organisms are also known as

carnivores.

Includes some birds, larger rodents, snakes, toads, lizards, raccoons, etc.

Insect-Eating Birds Larger Rodents

Tertiary Consumer

Gain energy and matter by consuming secondary consumers, and are also

known as carnivores.

Includes bears, foxes, coyotes, hawks, owls, wolves, lynx, cougars, etc.

Bears Hawks

Decomposer

While not always included in a food chain or web, decomposers are

responsible for breaking down dead organisms. Without decomposers, the matter and energy remaining in dead

organisms would not be recycled back into the environment. Decomposers

are also known as detritivores.

Decomposers may include bacteria, fungi, worms, and insects as examples.

Mushrooms & Insects



Producers are also known as autotrophs, and consumers are known as heterotrophs. It is important to note that not all organisms fit into a single group. Some organisms may gain matter and energy from consuming organisms in more than one trophic level. For example, bears may consume a primary consumer, such as a deer, as well as consume nuts and berries (producers). In this case, an organism that consumes both producers and consumers is called an omnivore. It is also important to note that some ecosystems are more complex, and can have additional trophic levels.

Food chains and food webs can be used as visual tools of organisms’ feeding patterns within an ecosystem. A food chain represents a single “chain” of organisms that consume each other, from producer to the primary consumer to the secondary consumer and to the tertiary consumer. A food web is much more complex, and shows all of the interactions between producers and consumers within an ecosystem. In any food chain or food web, arrows represent the movement of energy and matter from one organism to another. A food chain and a food web for organisms in a forest biome are represented below. Food Chain Food Web

http://www.quia.com/files/quia/users/solanoni/LifeScienceLesson5/consumers

Matter and Energy Within a Food Chain and Food Web Plants or algae form the lowest level of the food web. At each link upward in a food web, only a small fraction of the matter consumed at the lower level is transferred upward, to produce growth and release of energy in cellular respiration at the higher level. Given this inefficiency, there are generally fewer organisms at higher levels of a food web. Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded. The chemical elements that make up the molecules of organisms pass through food webs and into and out of the atmosphere and soil, and they are combined and recombined in different ways. At each link in an ecosystem, some amount of matter and energy are conserved.



It is important to remember that energy cannot be created or destroyed—it only moves between one place and another place, between objects and/or fields, or between systems. When a consumer eats another organism, some of the energy is used or stored, but most of the energy is transformed into heat energy and returns to the atmosphere. For this reason, the amount of energy available is highest in producers, and least in consumers at the top of the food chain. The continuous loss of heat energy requires an outside energy source (the sun) to maintain a flow of energy into an ecosystem.

Ecological Pyramids Researchers use population, biomass, and energy pyramids to track the flow of energy and cycling of matter through an ecosystem. The pyramid of numbers (see A) tracks population sizes of organisms within an ecosystem. The pyramid of numbers accounts for the total population of organisms within a specific ecosystem at each trophic level.

Biomass is the total mass of organisms within each trophic level. Biomass is calculated by weighing organisms and subtracting the mass of water that makes up the organism. A biomass pyramid (see B) compares the amount of biomass in organisms at each trophic level and is represented as grams per meter2 (g/m2).

An energy pyramid (see C) is used to illustrate the flow of energy between each trophic level. Approximately 90% of energy is lost at each trophic level. Energy is represented as kilocalories produced per meter2 per year (kcal/m2/yr).

Ecological pyramids are useful for characterizing the structure of an ecosystem. The pyramids for each ecosystem are slightly different. In addition, changes in the structure of an ecosystem’s ecological pyramids over time can provide information about the relative stability.

Energy and the Calorie The most common measurement of energy that we use with regard to food is the calorie. The calorie is the amount of energy required to increase the temperature of 1 gram of water 1° C. The calories you read about on food labels are actually Calories (yes, there is a

http://science.jrank.org/kids/article_images/chains_p10.jpg

http://www.eplantscience.com/index/general_zoology/images/images39/fig014.jpg



difference!). A Calorie with a capital C is actually a kilocalorie (kcal), or 1000 calories. In other words, a Calorie is the amount of energy required to increase the temperature of 1 kilogram of water 1° C. [In scientific contexts, the term “calorie” almost always refers to the small “c” calorie. For food, “calorie” can be assumed as Calorie.] The human body requires energy, and therefore Calories, to think, move, breathe, perform cell functions, and basically survive. At the molecular level, our bodies perform a wide variety of complex chemical reactions, many of which require energy. In general, the amount of energy we consume should be used by our bodies, or otherwise it will be stored for later use. When the amount of Calories we take in far outnumbers the amount of energy we use, the energy can build up as fat. Over an extended period of time, this can lead to an individual being overweight, which can result in health issues such as high blood pressure, diabetes, and metabolic imbalances. On the other hand, if the number of Calories consumed is less than that of the energy being used, the body will break down body structures to look for energy. Over an extended period of time, this can lead to an individual being underweight, which can also result in health issues such as recurring infections, anemia, and malnutrition. The following table outlines some activities and how many Calories they require.

Review Questions – answer questions on a separate sheet of paper 1. What is a trophic level? Give an

example. 2. What is the difference between a

producer and a consumer? Give an example of each.

3. Why are decomposers important to an ecosystem?

4. What is the difference between an herbivore, a carnivore, and an omnivore?

5. What is the purpose of a food chain and a food web?

6. How is matter cycled within a food chain and a food web?

7. How does energy flow through a food chain and a food web?

8. What happens to most of the energy that a consumer consumes?

9. Compare and contrast a pyramid of numbers, a biomass pyramid, and an energy pyramid.

http://www.acefitness.org/fitfacts/images/2009/2666B.gif

Review Questions – continued from above 10. What is the difference between a calorie and a Calorie? 11. What might happen if an individual consumes more Calories than will be used? 12. What might happen if an individual consumes less Calories than will be used? 13. A 160 lb. college student consumes a bowl of cereal containing 750 Calories in the morning. He

then sits quietly in class for 4 hours, and then goes for a 30-minute run. How many Calories did he use, and was it more or less than he consumed?



HASPI Medical Biology Lab 12a Scenario Energy flow between organisms in a food chain is difficult to visualize. We can feel energy being released as body heat, but it is not visible. In this activity you will have the opportunity to simulate the flow of energy, represented by water, between organisms in a food chain.

Materials Water 5 Cups 5 Beakers (500 ml) Label sheet Calculator

Procedure/Directions Your lab team will be given tasks, or directions, to perform on the left. Record your questions, observations, or required response to each task on the right.

Task Response

1

Producers perform photosynthesis, and therefore store the solar energy directly from the sun in the form of chemical energy. No organisms in the food chain will contain more energy than producers. As consumers eat producers and other consumers, energy is lost. This means that consumers at the top of the food chain obtain the least energy.

2 Form a group of 6-7 students. Obtain 1 cup without a hole in the bottom, 4 cups with holes in the bottom, 5 beakers (500 ml), and a sheet of labels.

3 Each label represents a different organism in a food chain – producer, primary consumer, secondary consumer, tertiary consumer, and a quaternary consumer.

4 Place the producer label on the cup without a hole, and the consumer labels on the cups with holes.

5

Five group members each need a cup and beaker. The 6th group member will measure the amount of water in each beaker. The 7th group member will be the recorder (Table 1), and should have a pen or pencil.

a. What will represent energy in this activity? b. What do the cups represent? c. What does each marker or line represent? d. Hypothesize what will happen to the energy (water) as it moves through the food chain in this activity.

6 Your instructor will have an area set up for the activity. Take your supplies to the “start line.”

7 Read through steps 8 - 28 BEFORE starting this activity!

8

Notice that there are 5 markers or lines spread out in the area, and a water source has also been provided. The water will represent energy and each line represents an energy level. The amount of energy contained in each organism after it consumes the organism before it will be measured at each of these lines.



9 Measure out 500 ml of water using a beaker, and place it in the producer cup. The individual with the producer cup will be stationed at the start line.

10 Recorder: Record the amount of water in the producer cup in Table 1, Trial 1 for the producer.

11

The primary consumer will stand at the start line next to the producer. The secondary consumer will stand at the next line closest to the start line. The tertiary consumer will stand at the next line, and the quaternary consumer at the next (see image).

12

When the recorder says “go,” the producer will pour all of the water (energy) from the first cup into the primary consumer cup.

13

As soon as all of the water has been poured, the primary consumer will WALK as fast as possible to the next line where the secondary consumer is located. Try to spill as little water from the top of the cup as possible, and do not cover the hole in the bottom of the cup.

14 Once the primary consumer reaches the line, he or she will pour the entire contents of the cup into his or her 500 ml beaker. (You should not have let the cup drip into the beaker on the walk.)

15 The measurer and recorder will follow. Measure the amount of water left in the 500 ml beaker. Record this amount in Table 1, Trial 1 for the primary consumer.

16

When the recorder says “go,” the primary consumer will pour all of the water (energy) from the beaker into the secondary consumer cup.

17

As soon as all of the water has been poured, the secondary consumer will WALK as fast as possible to the next line where the tertiary consumer is located. Try to spill as little water from the top of the cup as possible, and do not cover the hole in the bottom of the cup.

18 Once the secondary consumer reaches the line, he or she will pour the entire contents of the cup into his or her beaker. (You should not have let the cup drip into the beaker on the walk.)

19 The measurer and recorder will follow. Measure the amount of water left in the 500 ml beaker. Record this amount in Table 1, Trial 1 for the secondary consumer.

20

When the recorder says “go,” the secondary consumer will pour all of the water (energy) from the beaker into the tertiary consumer cup.

21

As soon as all of the water has been poured, the tertiary consumer will WALK as fast as possible to the next line where the quaternary consumer is located. Try to spill as little water from the top of the cup as possible, and do not cover the hole in the bottom of the cup.

22 Once the tertiary consumer reaches the line, he or she will pour the entire contents of the cup into his or her 500 ml beaker. (You should not have let the cup drip into the beaker on the walk.)

!

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Quaternary Consumer

Start

End

!

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Quaternary Consumer

Start

End

!

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Quaternary Consumer

Start

End

!

Prod

uce

r Prim

ary

Co

nsume

r

Sec

ond

ary

Co

nsume

r

Tertia

ry C

onsum

er

Qua

terna

ry C

onsum

er

Start

End



23 The measurer and recorder will follow. Measure the amount of water left in the 500 ml beaker. Record this amount in Table 1, Trial 1 for the tertiary consumer.

24

When the recorder says “go,” the tertiary consumer will pour all of the water (energy) from the beaker into the quaternary consumer cup.

25

As soon as all of the water has been poured, the quaternary consumer will WALK as fast as possible to the end line. Try to spill as little water from the top of the cup as possible, and do not cover the hole in the bottom of the cup.

26 Once the quaternary consumer reaches the end line, he/she will pour the entire contents of the cup into the 500 ml beaker. (You should not have let the cup drip into the beaker on the walk.)

27 The measurer and recorder will follow. Measure the amount of water left in the 500 ml beaker. Record this amount in Table 1, Trial 1 for the quaternary consumer.

28 When finished, return everyone to the lines and repeat steps 10-27 recording for Trials 2-5.

29 Return to the classroom, and return the supplies to the instructor. Everyone in the group should copy the results from their recorder’s Table 1.

30 Individually, each group member should average the amount of water (energy) remaining for each organism from Trials 1-5. Record in Table 1.

31

Using the averages, calculate the percent of energy (water) remaining, and the percent of energy lost for each organism. (See formulas at right.) Record in Table 1.

Percent Energy Remaining

Average/500 x 100

Percent Energy Lost

Percent Energy Remaining – 100

32 What did the water in this activity represent?

Answer:

33

How was energy “lost” in this activity between each step of the food chain? In an actual ecosystem, how would this energy be “lost”?

Answer:

34

At which level in the food chain was the most energy lost? The least energy lost?

Answer:

35

What was the purpose of performing more than one trial?

Answer:

36

Summarize this activity, and how it represents the flow of energy through a food chain.

Answer:

!

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Quaternary Consumer

Start

End



Table 1. Energy Flow Through a Food Chain Water (Energy) Remaining in Cup (ml)

Food Chain Organisms

Trial 1

Trial 2

Trial 3

Trial 4

Trial 5

Average

Percent Energy

Remaining

Percent Energy

Lost

Producer

Primary Consumer

Secondary Consumer

Tertiary

Consumer

Quaternary Consumer

Graph the average percent of energy remaining and percent of energy lost for this food chain exercise below. Don’t forget to label your x-axis, y-axis, and a title for your graph!



Food Webs, Biomass, &HASPI Medical Biology Lab 12b Scenario In this activity you will construct a food web consisting of organisms from the chaparral or rainforest biome. Each organism in the food web contains information about its population, biomass, and energy contribution within a specific ecosystem. The chaparral biome population data was collected from San Diego, CA. The rainforest biome population data was collected from the Peruvian Amazon basin in South America. After the food web has been built, use the provided information to calculate and create a pyramid of numbers, biomass pyramid, and energy pyramid for the ecosystem.

Materials Biome template Scissors Tape Scrap paper Calculator

Directions Part A. Constructing a Food Web

Task Image

1 Obtain a biome template, scissors, tape, and 2 sheets of scrap paper. Cut out the organism cards on the organism sheet on the dotted lines.

2 Tape the two sheets of scrap paper together, and write “Rainforest Food Web” or “Chaparral Food Web” at the top of the paper depending on which organisms you have.

3

On the scrap paper, arrange the organism cards into a food web. Leave some space between each card. Your food web should consist of four levels. Producers should be at the bottom of the food web, followed by primary consumers, then secondary consumers, then tertiary consumers at the top of the food web.

4

If you are uncertain about what an organism’s food source may be, look on the back of the card for more information.

5

Once you are confident in the arrangement of your food web, place a piece of tape AT THE TOP edge of the card to hold it in place. You will need to be able to flip the card over to obtain the population, biomass, and energy information on the back for Part B.

http://ecosystems2.weebly.com/uploads/5/4/7/2/5472074/8615484.jpg?461

6

Draw arrows representing the transfer of energy between organisms. The arrow should point toward the organism that will be CONSUMING it.

7

When complete, have your instructor check your food web for accuracy. It is okay if your food web looks slightly different than other students’ food webs.

!



Part B. Population, Biomass, and Energy Pyramids Task Response

1

Data collected by researchers on population size, biomass, and energy can be used to determine the health and relative stability of an ecosystem. Data on population size, biomass, and energy availability at each trophic level can be analyzed and compared with future data to determine whether an ecosystem is stable or changing.

2 Using the organism card in the food web you created, determine which organisms are producers. Record the name of all the producers in Table 2, in the Producer column.

3 For each producer, look at the back of the card and record the population, biomass, and energy information for each organism in Table 2. Be sure to include the units!

4

Add all of the producer populations together to determine the total producer population for this ecosystem. Add all of the producer biomass together to determine the total producer biomass. Add all of the producer energy together to determine the total producer energy. Record these values as the “TOTAL” for each column in Table 2.

5 Repeat steps 2 - 4 for the primary consumers, secondary consumers, and tertiary consumers.

Table 2. Population, Biomass, and Energy Producers Primary Consumers

Organism Population Biomass Energy Organism Population Biomass Energy

TOTAL

TOTAL

Secondary Consumers Tertiary Consumers Organism Population Biomass Energy Organism Population Biomass Energy

TOTAL

TOTAL



6

Using the population, biomass, and energy totals for each trophic level, draw a pyramid of numbers, biomass pyramid, and energy pyramid on the back of the food web.

Example Biomass Pyramid

7

Use a ruler and create a scale on the paper to make the size of each step in the pyramids proportional to one another. See the example pyramids at right and in the Background.

8 For each pyramid: Title it; label each trophic level; include the totals; and use color.

9

In the pyramid of numbers, at which trophic level is most of the population located? The least population?

Answer:

10

Why do you think the population is distributed in this ecosystem in this manner?

Answer:

11

In the biomass pyramid, at which trophic level is most of the biomass located? The least biomass?

Answer:

12

Why do you think the biomass is distributed in this ecosystem in this manner?

Answer:

13

In the energy pyramid, at which trophic level is most of the energy located? The least energy?

Answer:

14

Why do you think the energy is distributed in this ecosystem in this manner?

Answer:

15

Explain how energy would flow through the food web.

Answer:

16

Explain how matter would cycle through the food web.

Answer:

17

Describe one possible food chain that can be found in your food web.

Answer:

18

Find a student with a different biome, and compare the pyramid of numbers, biomass pyramid, and energy pyramid of your biome to that of the other biome. How are they similar and how are they different?

Answer:



Energy Density and Weight ManagementHASPI Medical Biology Lab 12c Scenario How does the food we consume, and therefore the energy we consume, impact our health? Our diet should work to maintain a balance between the energy we consume, the energy we use, and the energy we store. When our diet is imbalanced, our weight and overall health can fluctuate. Read the article from the National Center for Chronic Disease Prevention and Health Promotion called “Low-Energy-Dense Foods and Weight Management: Cutting Calories While Controlling Hunger” and answer the questions below.

Materials Printed article OR Computer/Internet

Directions Task Response

1

Obtain a copy of the article named above, or go to the following website to access it:

http://www.cdc.gov/nccdphp/dnpa/nutrition/pdf/r2p_energy_density.pdf

Answer the questions below using information from the article.

2 What is energy density? Answer:

3

What is the difference between a low-density and a high-density food?

Answer:

4

Why does water lower the energy density of foods?

Answer:

5

What is the most energy-dense component of food? How much energy does it contribute?

Answer:

6

Give 3 examples of a low-density food.

Answer:

7

Give 3 examples of a high-density food.

Answer:

8

How can a low-energy-density diet help an individual lower his or her Calorie intake?

Answer:

9

How did the study by Ledikwe and colleagues support this hypothesis?

Answer:



10

How did experimental studies in lab settings support this?

Answer:

11

How did the study by Bell et al. support this?

Answer:

12

How did the study by Duncan and colleagues support this?

Answer:

13 How did the study by Shintani et al. support this?

Answer:

14

Summarize two studies that support the theory that low-energy-dense diets can help manage body weight.

Answer:

15

How can energy density be calculated from the Nutrition Facts Panel?

Answer:

16

Calculate and record the energy density next to each food, for each of the following food labels.

Big Mac Hamburger Nutrition Facts Serving Size 219 g Amount Per Serving Calories 563

Energy Density:

Broccoli Nutrition Facts Serving Size 71 g Amount Per Serving Calories 20

Energy Density:

French Fries Nutrition Facts Serving Size 68 g Amount Per Serving Calories 209

Energy Density:

Watermelon

Nutrition Facts Serving Size 154 g Amount Per Serving Calories 46

Energy Density:

Chicken Breast Nutrition Facts Serving Size 28 g Amount Per Serving Calories 82

Energy Density:

Cheddar Cheese Nutrition Facts Serving Size 132 g Amount Per Serving Calories 532

Energy Density:

17 Summarize the steps that can be used to create a diet low in energy density.

Answer:

18

Provide and summarize three strategies that you would be willing to use in order to create a diet low in energy density.

Answer:



Connections & Applications Your instructor may assign or allow you to choose any of the following activities. As per NGSS/CCSS, these extensions allow students to explore outside activities recommended by the standards.

1. COMPARING DIETS: There is much debate about the best diet choice for humans. Use the Internet to research vegetarian, vegan, and protein-based diets. Find a scientific research article that supports the health of each diet, and a scientific research article that refutes each one. Summarize the research and the results of each article. Cite your sources for each article that you used.

2. RESEARCH METABOLIC DISORDERS: Choose one of the following metabolic disorders: Alpers’ Disease, Barth Syndrome, Lactic Acidosis, Luft Disease, or Pearson Syndrome. Conduct research and create a newsletter, brochure, or poster that includes the following information:

a. Description of the disease b. Causes c. Symptoms d. Treatment options e. Prevalence (how many individuals have the disease) f. References: Cite at LEAST 3 sources and correctly cite each source. Following

each source, assess the accuracy and credibility of the source by determining which organization(s) or individual(s) endorse this site and monitor the information that is placed on or within the source.

3. CALCULATING CHANGES IN BIOMASS: You are the newest member of an ecological research team, and have been given the task of determining the relative stability of organisms in the pond ecosystem being researched. Tables 3 and 4 on the next page contain data collected by the research team. Complete the data still needed in the tables by calculating the amount of biomass for each species, each population, and each trophic level. Calculation directions and examples are below. Then answer the questions below using the calculated data.

a. What was the change in biomass between producers, primary consumers, secondary consumers, and tertiary consumers between January 2013 and August 2013?

b. Hypothesize what this change might indicate for the pond ecosystem?

Calculating Species Biomass Calculating Population Biomass Calculating Total Biomass Water Mass =

Percent Water x Average Mass

Species Biomass = Average Mass – Water Mass

Population Biomass =

Species Biomass x Population

Total Biomass =

Sum of all Population Biomasses

Example

Water Mass = 0.75 x 0.5 g = 0.375 g

Species Biomass = 0.5 g – 0.375 g = 0.125 g

Example

Population Biomass = 0.125 x 2,300,000 = 287,500 g

Example

Total Biomass = 287,500 + 200,000 + 95,000 =

582,500 g



Table 3. Pond Ecosystem Data January 2013 Producers

Species

Average Mass (g)

Percent Water

Species Biomass (g)

Population

Population Biomass (g)

Total Biomass (g)

Planktonic algae 0.5 g 75% 0.125 g 2.3 million 287,500 g Bushy pondweed 1.5 g 59% 985,232 Hornwort 2 g 61% 876,540

Primary Consumers

Species Average Mass (g)

Percent Water

Species Biomass (g)

Population Population Biomass (g)

Total Biomass (g)

Roman snail 1.8 g 81% 240,254 Mayfly 1.4 g 54% 458,023 Minnow 29 g 72% 129,897

Secondary Consumers


Percent Water

Species Biomass (g)


Total Biomass (g)

Striped bass 3.4 kg 67% 98,765 Brown frog 652 g 74% 54,321 Wood rat 785 g 63% 8,793

Tertiary Consumers


Percent Water

Species Biomass (g)


Total Biomass (g)

Blue heron 6.4 kg 39% 32 Red-tailed hawk 4 kg 34% 23 Garter snake 2.6 kg 43% 56 Table 4. Pond Ecosystem Data August 2013

Producers


Percent Water

Species Biomass (g)

Population

Population Biomass (g)

Total Biomass (g)

Planktonic algae 0.5 g 75% 3.1 million Bushy pondweed 1.4 g 58% 1.2 million Hornwort 2.1 g 59% 987,541

Primary Consumers


Percent Water

Species Biomass (g)


Total Biomass (g)

Roman snail 1.6 g 76% 245,897 Mayfly 1.5 g 49% 365,068 Minnow 29 g 68% 132,043

Secondary Consumers


Percent Water

Species Biomass (g)


Total Biomass (g)

Striped bass 3.3 kg 68% 68,301 Brown frog 457 g 72% 18,754 Wood rat 764 g 61% 12,864

Tertiary Consumers


Percent Water

Species Biomass (g)


Total Biomass (g)

Blue heron 6.6 kg 40% 21 Red-tailed hawk 4.2 kg 34% 12 Garter snake 3.1 kg 45% 72



Resources & References • CDC. 2011. Low-Energy-Dense Foods and Weight Management: Cutting Calories While Controlling

Hunger. National Center for Chronic Disease Prevention and Health Promotion Division of Nutrition, Physical Activity and Obesity, Research to Practice Series, No. 5. http://www.cdc.gov/nccdphp/dnpa/nutrition/pdf/r2p_energy_density.pdf.

• Hill, J.O., Wyatt, H.R., and Peters, J.C. 2012. Energy Balance and Obesity. American Heart Association, Circulation, 126: 126-132. http://circ.ahajournals.org.

Documents

12a Cycling of Matter & Energy Flow - Health and Science ... · PDF file328 Cycling of Matter & Energy Flow – Eating for Energy, HASPI Medical Biology Lab 12 Name(s): Period: Date: