Photosynthesis and

Cellular RespirationQuestions we will address: What do plants need? What do plants use for food? What is photosynthesis? Why do I breathe oxygen? Why do I eat food?

VOCAB 15PHOTO-

SYNTH-

-ESIS

AUTO-

-TROPH-

DI-

GLUC-

-OSE

CHLORO-

-PHYLL

-PLAST

Photosynthesis Q & AQ: What does photosynthesis mean?A: Photosynthesis is made of the following word parts: “photo” means light “synth” means to put together or make “esis” means processSo photosynthesis literally means “the process of using light to put together or make”.

Q: What is photosynthesis?A: Photosynthesis is the process by which plants make their own food. This is important, because, as we know, food provides us with energy.

Q: What is an organism that makes its own food called?A: Organisms that make their own food are called “producers” or “autotrophs”. (Organisms that do not make their own food are heterotrophs.) “Auto” means self “Troph” means food or nutrition So autotrophs, or producers, provide themselves with food or nutrition

Q: Why do plants need to make their own food?A: Plants are sessile organisms, which mean that they are anchored to one spot. Since plants can’t move around, they are unable to forage or scavenge for food.Even if plants were able to go out and find food to eat, they have no digestive organs to break the food down into a form useful to cells.

Q: What do plants need in order to survive?A: In order to survive, plants must be able to carry out photosynthesis. Several things must be present in order for photosynthesis to occur. Make a list below about what you hypothesize plants need in order to survive. ____________________________________________________________________________________________________________________________

Define the following terms in your own words:1. Photosynthesis

2. Autotroph:

3. Producer:

4. Sessile:

Plant Requirements/Balloon Plants

List of things I think all plants need:

According to the Balloon Plants, here’s what all plants really need:

Digging Deeper

Question: Do acorns and full grown oak trees weigh the same? Where does all of the matter come from that allows an acorn to gain so much mass? As the tree grows from a tiny acorn to mighty oak, the additional matter in the tree must come from somewhere. But where does it come from? That’s the question Jan-Baptiste van Helmont asked himself several hundred years ago.

Where do you think the matter in an oak tree comes from? Write your hypothesis here. ______________________________________________________________________________________________________________________________________________________________________

Let's travel back in time 350 years. It is now the year 1642. We are in Europe. It is a time of excitement and exploration and travel in this part of the world. Some people have found what they call a New World across the ocean (it is actually a very old world to the Native Americans living in this "New" World)! More and more people are getting interested in finding out about the why's of the world around us -- more people are interested in and finding benefactors who will pay them to do science experiments.

We are going to meet one of these early scientists. He is a physician but he also does experiments with plants. His name is Jan-Baptiste Van Helmont. He is from the country of Belgium and the year 1642. Almost everyone back in 1642 was sure that soil was the food for plants. Jan-Baptiste Van Helmont decided to prove them right (or wrong?).

Is soil food for plants? Write your hypothesis here. _______________________

Suppose a child was given 200 pounds of food to eat. Predict what would happen to the weight of that child as he or she gobbled up the food. Does the child's weight go up, go down, or stay the same? ____________________________________

What would happen to the weight of the food on the table as the child ate it? Does the weight of the food go up, go down, or stay the same? ___________________

Now think about a young tree planted in a bucket of soil. As the tree grows it gains weight. Does it gain weight from the soil the way a child gains weight from food? _______________________ Is the soil a kind of food for the plant? ________ Write down below whether you think the weight of the soil will go up, go down, or stay the same as the tree grows: _____________________________________

In the 1600's everyone thought that the soil and minerals in the soil were the food for the plants. A scientist named Jan Van Helmont did an experiment to see if this was true. He planted a five-pound young willow tree (Salix sp.) weighing five pounds in a bucket containing 200 pounds of soil. He watered the tree regularly but he did not add any more soil.

After five years, Van-Helmont weighed the tree again and found that it weighed 174 pounds, however, the weight of the soil only decreased by two ounces! In the chart below, record the initial and final weights of both the tree and the soil.

Tree Soil

Original Weight

Weight after Five Years

Does Van Helmont's experiment give us evidence to say that soil is or is not food for plants? Explain your thinking. ______________________________________________________________________________________________________________________________________________________________________

Are minerals in the soil food for plants? _______________________________

Everyone says that plants take in minerals from the soil. Minerals do not have very much weight, but they do weigh something. So do you think Dr. Van Helmont’s tree took in minerals from the soil? _______

About how much weight did the tree get from the minerals? _______

Do you think this amount of minerals could explain how the tree gained 169 pounds? Explain your thinking. ___________________________________________________________________________________

Is water food for plants? Van Helmont thought that his experiment was evidence that water must be food for plants. He thought that if soil and the minerals in the soil were not giving the tree its food, then the tree must be gaining weight by getting food from the water. After all, he had been watering the tree every day for five years.

Water helps the tree to grow, but does it give the tree energy? Could the tree live and grow if all it took in was water? Explain your thinking. ______________________________________________________________________________________________________________________________________________________________________

Before Van-Helmont’s experiment, where did people believe that trees got their food? ___________________________________________________________________________________

Briefly summarize Van-Helmont’s experiment. What was he testing? What was his procedure? What materials did he use? What were his observations? Conclusion?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

In science, experiments more often than not lead to more questions than they do answers. What question was answered by Van-Helmont’s experiment? ___________________________________________________________________________________

What did van-Helmont erroneously conclude from his experiment? ______________________________________________________________________________________________________________________________________________________________________

Why is it important that scientists continuously experiment on topics that other scientists have already made a conclusion about? (Hint: Think about the conclusion van-Helmont drew from his experiment.) _____________________________________________________________________

What does soil provide for plants? ____________________________________________

Photosynthesis Counts

1. What do plants need in order to carry out photosynthesis in order to survive?

2. What do plants produce as a result of photosynthesis?

3. In our experiment with coleus and geranium leaves, what did we observe was present in the leaves. (Starch) How can you explain this?

4. Is this a balanced chemical equation?

By doing the Flaming Hot Cheeto lab, I learned that__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Plants turn sunlight into food during ___________________________. Animals get food by eating. So, then, how does food get turned into energy?

An organelle called the __________________________ turns food into energy. This process is called _________________________________.

Here’s how it works:1. An organism makes or eats food.2. The food must be burned to create energy, so the organism takes

in ________________________.3. This creates energy in the form of a molecule called ___________.4. Wastes are also created. One of the wastes is

_________________, which we exhale.5. Another waste is water, which we _____________________ out.

NOTE: ALL ORGANISMS, EVEN PLANTS, GO THROUGH CELLULAR RESPIRATION!!!

VOCAB

Glucose + oxygen → carbon dioxide + water

OxygenCarbon dioxide

PHOTOSYNTHESIS

PRODUCER

AUTOTROPH

SESSILE

CARBONDIOXIDEOXYGEN

GLUCOSE

STARCH

CHLOROPHYLL

CHLOROPLAST

STOMATA

CELLULARRESPIRATIONMITOCHONDRIA

PHOTOSYNTHESIS AND CELLULAR RESPIRATION REVIEW PROBLEMS

1. What is the difference between an autotroph and a heterotroph?

2. Which of the following would most decrease the amount of carbon dioxide in the air?a) a growing maple tree c) a running dogb) a person driving a car d) a burning forest

This data was collected by placing equal amounts of various plant parts in sealed containers and exposing them to various light colors. After 8 hours in the container, the increase in oxygen was measured in the container.

3. One could compare the amount of oxygen produced in 8 hours at two different light colors by comparing which two containers? Explain why you chose this pair.

4. In which container was photosynthesis taking place the fastest? Explain why you chose this container.

5. In which container was photosynthesis not occurring? Explain why you chose this container.

6. According to the data, which variable determined whether or not photosynthesis occurred?

7. Plants must have a constant supply of _________________ for photosynthesis, but they provide _______________ for cellular respiration.a) water—carbon dioxide c) carbon dioxide—waterb) carbon dioxide—oxygen d) oxygen—water

8. How does ATP store energy?

9. Why would human muscle cells contain many more mitochondria than human skin cells?

10. How are photosynthesis and cellular respiration complimentary processes?

Air is composed of a number of different gases. As a result of cellular respiration, the percentages of some gases in the air are altered by the time the air is exhaled from the body. Study the table. It compares the relative percentages of gases in the air.

11. What information about cellular respiration is conveyed in the table?

12. Why are carbon dioxide levels higher in air that is exhaled?

BTB / Elodea LabMaterials4 test tubes 4 pieces of tape WaterBromothymol blue (BTB) Drinking Straw 2 sprigs of Elodea4 test tube lids Well-lit area Dark areaTest tube rack Goggles Colored pencils

SafetyTo avoid swallowing BTB, do not place the straw very far down into the liquid. Blow slowly. Wear goggles.

Day 1Procedure

1. With your 4 pieces of tape, label your 4 test tubes A, B, C, and D.

2. Also write your group number and hour on the tape.

3. Fill all 4 test tubes 1/2 full of water and place them in your test tube rack.

4. Add BTB to each test tube. What color is the liquid inside of the test tubes? _________________

5. Color the test tubes on Figure 1 the same color as the liquid inside each of the test tubes. Does this color indicate that carbon dioxide is present or absent? __________

6. Place a straw in each test tube.

7. Blow into the straws slowly until the liquid turns yellow. Do not allow the solution to exit the test tube.

8. In the blank spaces on Figure 2, write what you have added to the solution.

9. Color the test tubes in Figure 2 to reflect the color of your solution.

10. Place a sprig of Elodea into test tubes B and D. Which test tubes do not contain Elodea? __________________

11. Place a cap tightly on all 4 test tubes.

12. Place test tubes A and B in the well-lit area designated by your instructor. Be careful not to disturb other test tubes in the area.

13. Place test tubes C and D in the dark area designated by your instructor. Be careful not to disturb other test tubes in the area.

14. Clean your lab area and throw your straws away.

15. Sit at your desk and complete day one questions.

Day 2 (After 48 hours)

1. Observe your four test tubes.

2. Color the test tubes in Figure 3 to reflect the colors of your solutions.

3. Throw your Elodea in the trashcan, and pour your solutions down the sink.

4. Clean your test tubes, other equipment and lab table.

5. Sit quietly at your desk and complete the following questions.

Day 1 Questions1. What does bromothymol blue (BTB) test for?

2. Typically, what color is BTB?

3. What color does BTB become when its substrate is present?

4. Did the liquid inside the test tube change colors when you blew into it?

5. If so, what does this color change mean?

6. What do you exhale when you breathe out?

7. What did you add to the solution in the test tube when you blew into it?

8. What plant did we use for this experiment? _____________________

Day 2 Questions1. What happened in each test tube after 48 hours?

A: ______________________________________________________

B: ______________________________________________________

C: ______________________________________________________

D: ______________________________________________________

2. What does a reversal in the color change of the solution in the tubes represent?

3. Based on your observations, what can you conclude about what plants require?

Figure 1: Color of the Water and BTB solution

Figure 2: Color of the Water and BTB Solution After Blowing Into the Straw

Figure 3: Color of the Water and BTB Solution after 48 Hours