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Homework Packet

CHEMISTRY OF ECOLOGY

Name KEY

Date Period

HW #1: 30.2 – Summary of Biochemistry – Food and Nutrition

Directions: Utilize your textbook (Chapter 30: Digestive and Excretory Systems - pages 868-873) to

complete this activity. The “*” indicate answers taken directly from the textbook pages.

We will start off with an overview of why we need to eat and what nutrients are necessary to provide energy for life activities.

Food and Energy

Have you ever wondered why you need food? The most obvious answer is *__energy____________.

Molecules in food contain *__chemical___ __energy____ that cells use to produce *_ATP___. Food also supplies raw *__materials_______________ your body needs to build and repair tissues.

Energy. The energy available in food can be measured in a laboratory in a very simple way - by *__burning_____________ it. When food is burned, most energy in the food is converted to *___heat________, which is measured in units called *__calories______________.

*Think! What does cellular respiration have in common with the act of burning food in a laboratory?Both processes convert energy from one form to another. Burning = chemical to heat/light; Cell Resp = chemical to heat/chemical both are forms of “combustion” essentially

“calorie”:* the amount of heat needed to raise the temp of 1 gram of water by 1 degree Celsius.

“Calorie”:*dietary calories (as seen on labels) = 1000 calories, or 1 kilocalorie (kcal)

The energy stored in food molecules is *__released______________ during *__cellular_________ _respiration_________ and used to produce the *_ATP_______ molecules that power cellular activities.

Raw Materials. Chemical pathways, including cellular respiration, can extract *_energy______ from almost any type of food. However, it does matter which foods you eat. What is the reason?* food also supplies the raw materials used to build and repair body tissues.

What are some of the substances your body makes using raw materials obtained from food?* enzymes, lipids in cell membranes, DNA

Can your body make every substance that it needs?*no. food contains at least 45 substances that the body needs but cannot make.

A healthy diet ensures that your body receives all the raw materials that it needs.

Nutrients

Nutrients are:* substances in food that supply the energy and raw materials your body uses for growth, repair and maintenance.

The nutrients that the body needs include:* water, carbohydrates, fats, proteins, vitamins and minerals

Water. The most important nutrient is water – every cell in the human body needs water because many of the body’s processes, including *_chemical__ _reactions_____, take place in water. It is a major component of body fluids and cellular fluids.

As you recall, the two categories of nutrients which are the most important sources of energy for the body are Carbohydrates and Fats.

Carbohydrates. Simple and complex carbohydrates are a major source of *__energy_____ for the body.

List at least three examples of foods that are rich sources of carbohydrates:*milk, bread, fruit

Simple carbohydrates (monosaccharides and disaccharides) include the sugars found in *_fruits______, *_honey_______ and *_sugar cane______________.

Complex carbohydrates (polysaccharides) include the starches found in *_grains____________, *___potatoes_________ and *_vegetables______________.

In animals, starches are broken down by the digestive system into *simple____ ___sugars___ which are then absorbed into the *__blood____________ and carried to *_cells_____________ throughout the body. Excess blood sugar is converted into *__glycogen_______ which is stored in the *__liver____________ and *__skeletal ___ __muscles______. Excess sugar may also be converted to and stored as body *__fat_______. Carbohydrates are important for short-term energy storage.

What is another name for “fiber”?* cellulose . Foods high in fiber include * whole-grain breads, bran and many fruits/vegetables

Can the human digestive system break down cellulose?*__no._______

What are two benefits of cellulose in our diet?*it supplies bulk which helps muscles move food and wastes through your digestive system; also may reduce the risk of heart disease and type II diabetes.

Fats. Fats are an important part of a healthy diet. Fats help the body absorb fat-soluble *_vitamins___________ and are part of *_cell_______ _membranes___________, *___nerve______ __cells______, and certain *__hormones_______________. Deposits of fat *__protect__________ and *__insulate_________ body organs and are a source of *_stored___________ __energy__________. Fats come in a wide variety of forms and some types are healthier than others.. Fats are synthesized by animals and oils are synthesized by plants. Both molecules store 2 times the amount of energy than the same amount of carbohydrate. (Energy of 1 gram of fat =energy of 2 grams of carbohydrate.) Fats and oils are important for long-term energy storage.

Proteins. Proteins can be used as energy sources when other nutrients, such as carbohydrates and fats, are in *__short______ __supply_________.

Vitamins. These organic molecules are needed by the human body in very small amounts. Most are needed by the body to help perform *_chemical____ ____reactions_________. If we think of proteins, fats, and carbohydrates as the building blocks of the body, then vitamins are the * tools that help to put them together.

There are many different vitamins, with widely varying functions; having too little or too much of certain vitamin(s) can have serious health consequences.

Examples:* Vitamin A, K, C, etc…

Minerals. These inorganic nutrients are needed by the human body in small amounts. Most are needed to assist with certain metabolic processes or to help build cells or tissues.

Examples:* Ca, P, Fe, Cl, Na, K, Mg, F, I, Zn

To summarize, a balanced diet provides nutrients in adequate amounts and enough energy for a person to maintain a healthful weight.

Image Source:

If you undergo prolonged starvation, what order will you use the following organic compounds to obtain energy? Choices: glucose, ATP, proteins, fats, carbohydrates

___atp________ ( __glucose__ ( _complex carbs_ ( _fats____ ( __proteins____

HW #2 Energy and Matter in Ecosystems

Study and think about the diagram below to answer the questions which follow.

Can matter be recycled in an ecosystem?Yes

Can energy be recycled in an ecosystem?No:

Compare and contrast the flow of energy through an environment with the flow of matter through that same environment.

Flow of matter is a cycle, matter is reused; energy is not reused. The water in the water wheel above provides energy that is used to do work in the factory. Once the water flows past the wheel, it cannot provide any more energy. This is analogous to the energy that sunlight provides to primary producers which is used to do cell work in the primary producers and all consumers that get their energy from them. Once that energy is used in cell respiration, it cannot be reused. All energy in ecosystems must be continually restored by the primary producers.

HW # 3 Inquiry Into Scientific Thinking: The 10 Percent Rule

Food chains show the path of energy through an ecosystem. As you move through the food chain, energy is lost. Scientists estimate only 10 percent of energy passes from one level to the next. This is why most food chains are not very long.

1. Look at the four empty 2-liter water bottles shown above. Remember 2 liters is the same as 2000 mL.

2. Imagine that the amount of water in a bottle represents energy in a food chain. The first bottle represents producers. Using a red pencil, color in the bottle so it is full. In other words, it has 2000 mL of water. This will represent 100% of the energy available.

3. Think about what the 10 percent rule says about energy. Look at the bottle representing first-level consumers. Use the red pencil to color in how much water (equivalent to energy) this bottle would contain.

4. Use the red pencil to color in the amount of water in the bottle for second-level consumers.

5. Use the red pencil to color in the amount of water in the bottle for third-level consumers.

Analyze and Conclude

1. What do you notice about the water levels in the bottles as you move through the food chain?

It reduces by 90% each level

2. How much water was available for the second-level consumer?

A. 2000 mL C. 20 mL

B. 200 mL D. 2 mL

3. Imagine this food chain: A hawk eats a robin. The robin ate a grasshopper. The grasshopper ate grass. Which organism is the source of energy for the food chain? GRASS

4. In a food chain, do the carnivores or the herbivores receive more of the energy supplied by the producers at the base of the food chain? Explain.

Herbivores because they are the primary consumers – only one 90% loss. Fewer carnivores can be supported because they are secondary consumers – at least two 90% losses

HW #4 - Biological Molecules Which Provide Energy

Use the following choices to answer the questions which follow.

a. lipids (fats and oils)

b. simple sugars such as glucose

c. complex carbohydrates such as starch and glycogen

d. ATP

e. proteins

_d___1. The most directly usable form of energy in a cell. Used to power cellular processes.

_e___2. The cell’s last preferred choice of molecules to be used for energy.

_b___3. Molecule which is directly used in cellular respiration.

__d_4. Molecule which is produced by the energy released through cellular respiration.

__a__5. Long-term energy storage molecules which a cell will use for energy after immediately available and stored carbohydrates are used up first.

__c__6. Short term energy storage polysaccharides in animals and plants.

7. Fill in the chart below with the missing blanks to show the general order of preference for energy molecules utilized in a cell.

__ATP___ ( __Glucose_ ( Glycogen_ ( __Lipids__ ( _Proteins___

Polysaccharide

HW #5 Water Cycle

Use the following terms to complete the descriptions below.

a. Evaporation b. Transpiration c. Condensation

d. Run-off e. Precipitation

1. __________E_ Droplets of water in clouds become large enough so that they fall to the earth in the form of rain, snow, sleet or hail

2. _________C___ Water vapor cools and the vapor condenses into liquid droplets which form clouds

3. _________A___ Liquid water turns into water vapor

4. _________D___ Liquid water flowing along the surface of the earth

5. _________B___ Evaporation of water from the leaves of plants

Use the words in the box to label the parts of the water cycle.

HW #6 Carbon-Oxygen Cycles

Match the term with the best description:

a. Photosynthesis b. Cellular Respiration c. Fossil Fuels

__C__1. Carbon-containing compounds that were once part of ancient forests, marine organisms, or other animals that have been buried and transformed into energy-rich fuels.

__A__2. Producers use carbon dioxide and water to form glucose and oxygen. This process stores energy.

__C__3. Coal, oil and natural gas are examples

__B__4. All organisms (producers and consumers) use glucose and oxygen to form carbon dioxide and water. This process releases energy.

5. Which gas is released in great quantities into the atmosphere when fossil fuels are burned? CO2

6. What is the Greenhouse effect?

Excess CO2 in the atmosphere causes heat to be trapped by the earth’s atmosphere, causing temperatures to rise.

7. Why can the Greenhouse Effect be harmful?

The increased temperatures caused by the greenhouse effect changes weather and climate patterns and can be harmful to organisms which cannot tolerate the change in temperature (it is stressful for them to maintain homeostasis).

8. What is the connection between the Greenhouse Effect and the burning of fossil fuels?

Burning fossil fuels releases CO2, thus contributing to the greenhouse effect.

HW #7 Carbon-Oxygen Cycles Revisited

1. Plants use CO2 in the process of photosynthesis to make glucose and oxygen.

2. Animals use oxygen in the process of respiration and make more CO2.

3. The ocean is the main regulator of CO2 in the atmosphere because CO2 dissolves easily in it.

4. In the past, huge deposits of carbon were stored as dead plants and animals decayed.

5. Today these deposits are burned as fossil fuels, which include coal, oil, and natural gas.

6. More CO2 is released in the atmosphere today than in the past because of burning of fossil fuels.

7. Another source for CO2 is volcanoes.

8. Too much CO2 in the atmosphere may be responsible for the greenhouse effect.

9. Write the equation for photosynthesis:

6CO2 + 6H2O ( C6H12O6 + 6O2

1. Plants release 430-470 billion tons of oxygen during the process of photosynthesis.

2. Atmospheric oxygen in the form of ozone provides protection from harmful ultraviolet rays.

3. Oxygen is found everywhere on Earth, from Earth’s crust (rocks) to the oceans where it is dissolved.

4. Oxygen is vital for cellular respiration by animals, a process which produces CO2 and water.

5. Oxygen is also necessary for the decomposition of waste into other elements necessary for life.

6. Write the equation for cellular respiration:

C6H12O6 + 6O2( 6CO2 + 6H2O

HW #8 Nitrogen Cycle

1. All organisms require nitrogen to build ___proteins___ and

__nucleic acids__ (choose from : carbohydrates, lipids, proteins, nucleic acids)

Match the term with the best description.

a. Decomposers b. Nitrogen fixation c. Denitrification

__B__2. The process in which certain types of bacteria convert nitrogen gas into ammonia

__A__3. These organisms release nitrogen from waste and dead organisms

__C__4. The process by which certain types of bacteria convert nitrates into nitrogen gas which is relased back into the atmosphere.

_A__1. Which statement about this cycle is true?

a. All the nitrogen obtained by animals can be traced back to the eating of plants

b. Plants fix nitrates into atmospheric nitrogen gas.

c. Nitrogen atoms are continually created and destroyed.

__A_2. Which statement about this cycle is false?

a. Plants, but not animals are parts of the nitrogen cycle.

b. The nitrogen cycle requires nitrogen-fixing bacteria.

c. Bacteria convert nitrogen gas into a form in which it can be used as a plant nutrient.

d. Bacteria and fungi break down dead plant and animal tissues into nitrates that plants can use.

__B_3. What is the name of the process that converts nitrogen gas into ammonia?

a. Nitrification b. Nitrogen fixation

c. Decay d. Denitrification

__C_4. Organic compounds in dead organic matter and wastes are converted into ammonia as a result of:

a. Nitrgen fixation b. Denitrification c. Decomposition

__B_5. Bacteria responsible for nitrogen fixation are found in the roots of:

a. all plants b. certain plants, such as legumes c. evergreen trees

__A_6. Animals get their “organic nitrogen compounds” by:

a. Feeding

b. Breathing

c. Performing photosynthesis

__C_7. Why do organisms need nitrogen?

a. To make carbohydrates

b. To make lipids

c. To make proteins and nucleic acids

__C_8. What is the approximate % of nitrogen gas in our atmosphere?

a. less than 1% b. 25-30% c. 75-80% d. over 95%

__B_9. Why is it so difficult for most organisms to use nitrogen gas from the atmosphere?

a. Nitrogen is a non-reactive atom.

b. A strong triple covalent bond holds the molecule together.

c. Oceans quickly absorb nitrogen gas, so not much is available in the air.

__A_10. ___?___ are the primary organisms which drive the nitrogen cycle.

a. bacteria b. animals c. plants

HW #9 - Photosynthesis and Cellular Respiration

Use the diagram below to answer the next question.

Solar energy Chemical energy (food) Chemical energy (to do cell activities A B

1. The process indicated by the arrow labeled A is (circle one): photosynthesis /cellular respiration

2. The process indicated by the arrow labeled B is (circle one): photosynthesis /cellular respiration

3. Which process photosynthesis or cellular respiration USES CO2? _____photosynthesis_____________

4. Which process photosynthesis or cellular respiration extracts the energy from food? ___cellular respiration_____

5. Using TWO different colored pencils - indicate the movement of the gases CO2 and O2. (Hint – bacteria in the soil get no sunlight and therefore are NOT producers.)

Fill in the following chart—some answers have been filled in for you:

| |Photosynthesis |Cellular Respiration |

|What is the purpose of the reaction – to RELEASE or STORE | | |

|energy? |store |release |

|Chemical Equation | | |

| |CO2 + H2O ( C6H12O6 + O2 |C6H12O6 + O2 ( CO2 + H2O |

| | | |

|Reactants | 1) carbon dioxide |1) _glucose__________ |

| |2) _water_______ |2) oxygen gas |

| | | |

|Products | | 1) water |

| |1) glucose |2) _carbon dioxide____ |

| |2)_oxygen__________ | |

|How is the first reactant obtained by the organism? |CO2—Obtained from the air through the cell | |

| |membrane or through openings in the leaf. |Plants:_make glucose through photosynthesis________________|

| | | |

| | |Animals:__eat food____________ |

| | | |

|How is the second reactant obtained? | |O2—Plants obtain it through the cell membrane or stoma. |

| |Uptake through the roots |Animals breathe it in through lungs. |

| | | |

|How is the first product used? | |H2O--Used by plants as a reactant in photosynthesis—Used by|

| |As a reactant to make ATP in CR |animals in various reactions (such as hydrolysis, etc.) or |

| | |eliminated as waste. |

|How is the second product used? | |CO2--Used by plants as a reactant in |

| |As a reactant to make ATP in CR |photosynthesis—Eliminated as waste by animals during the |

| | |breathing process. |

|What molecule or energy source (sun) provides energy for | | |

|the reactions? |sun |Food (glucose) |

|What types of organisms conduct this process – consumers, | | |

|producers, or both?) |Producers, photosynthesizers |ALL living organisms |

HW #9 BIOTIC RELATIONSHIPS IN THE ENVIRONMENT

□ Symbiosis - a relationship in which two organisms of different species 'live together' for a period of time

□ Parasitism - a form of symbiosis in which one organism derives nutrients from the second organism which suffers some harm but is usually not killed (e.g. A tick is the parasite that feeds off a dog which is the host .)

□ Mutualism - a form of symbiosis in which both organisms benefit each other (e.g. bacteria in your intestines-they get food and warmth and make vitamins for you)

□ Commensalism - a form of symbiosis in which one organism helps the other organism, but there is no benefit nor harm done in return (e.g. A clown fish lives inside a sea anemone and is protected by it. The sea anemone derives no benefit nor harm from the relationship.)

□ Predator / Prey Relationships – the relationship in which one organism (predator) hunts and eats another

( prey ) (e.g. an owl captures and eats a mouse )

□ Competition – a relationship where two types of organisms compete for the same resource such as food,

water , shelter, light, mate, etc (e.g. sheep and kangaroos compete for grass)

HW #13 Symbioses

1. Complete the table about main classes of symbiotic relationships.

|Main Classes of Symbiotic Relationships |

|Class |Description of Relationships |

|Mutualism |Relationship in which both organisms benefit (+/+) |

|Commensalism |Relationship in which one organism benefits and the other is unaffected (+/0) |

|Parasitism |Relationship in which one organism benefits and the other is harmed (+/-) |

For Questions #2-8: Match the example with the type of relationship. A relationship type may be used more than once.

Type of Relationship

A. mutualism

B. commensalism

C. parasitism

Example

C 2. a tick living on the body of a deer

A 3. a bee eating a flower’s nectar and picking up the flower’s pollen

B 4. a barnacle living on a whale’s skin

C 5. a tapeworm living in a person’s intestines

A 6. an aphid providing food to an ant in exchange for protection

B 7. Some orchids grow high on trees so that they can get enough light for photosynthesis. The trees are unaffected by the presence of the orchids. How would you classify the relationship between the orchids and the trees?

C_8. A symbiotic relationship in which one organism is harmed and another benefits

Directions – Read each paragraph below. Each paragraph describes one OR MORE relationships between organisms. Next to each, write the name of the organisms, and the type of relationship they have.

Be sure to identify EVERY relationship you can.

Choices: Mutualism, Commensalism, Predation, Parasitism, Competition

-----------------------

FULL

2000 ml 200 ml 20 ml 2 ml

condensation root uptake evaporation

runoff transpiration precipitation

condensation

precipitation

evaporation

Run-off

transpiration

Root uptake

Coal Oil Natural Gas burning of fossil fuels volcanoes

Photosynthesis Respiration ocean sugar Greenhouse decayed

Photosynthesis Ozone Waste Crust Oceans Cellular Respiration

CO2

O2

ENVIRONMENTAL

RELATIONSHIPS

BIOTIC

FACTORS

ABIOTIC

FACTORS

PREDATOR-PREY

RELATIONSHIP

COMPETITION

SYMBIOSIS

Commensalism

Mutualism

Parasitism

CP Environmental Science Name: ____________________

Leeches/ Croc (+/-) Parasitism

Plovers/Leeches (Predator/Prey) Predation

Plovers/Crocs (+/+) Mutualism

Epiphytes/ Ants (+/+) Mutualism

Fish/ Trees (+/+) Mutualism

Bird/ Orchid (+/+) Mutualism

Insect/ Orchid (+/+) Mutualism

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