Cell Energy SE - Bio PDF

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Name: Bethany Smith

Date: 16/10/2021

Student Exploration: Cell Energy Cycle Vocabulary: aerobic, anaerobic, ATP, cellular respiration, chemical energy, chlorophyll, chloroplast, cytoplasm, glucose, glycolysis, mitochondria, photosynthesis, radiant energy

Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. What does a plant need to survive and grow? H2O, CO2, Sun.

2. What does an animal need to survive and grow? Food, water as well as oxygen.

3. How do animals and plants depend on each other? Plants are able to provide oxygen and food in order for animals to survive and they depend on each other in this way. Plants can also be a form of shelter for animals. Animals can sometimes provide plants with water and with carbon dioxide.

Gizmo Warm-up The Cell Energy Cycle Gizmo™ illustrates two processes that are essential to life: photosynthesis and cellular respiration. Although both of these processes involve a series of complex steps, the inputs and outputs of each process are four relatively simple molecules. 1. What is the chemical formula of oxygen? O2

2. Glucose is a simple sugar. What is the chemical formula of glucose? C6H12O6

3. What is the chemical formula of carbon dioxide? CO2

4. What is the chemical formula of water? H2O

Get the Gizmo ready: Activity A: Photosynthesis

 If necessary, click Reset.  Check that the PHOTOSYNTHESIS tab is selected. Check that Description is turned on.

Introduction: Photosynthesis occurs in the chloroplast, an organelle found in plant and algae cells. Within the chloroplast, a green pigment called chlorophyll converts the radiant energy of sunlight into chemical energy that the plant can use. Question: What are the inputs and outputs of photosynthesis? 1. Predict: Of the molecules shown on the MOLECULES pane, which do you think are inputs (ingredients) in photosynthesis? Which do you think are outputs? Inputs: H2O, CO2

Outputs: C6H12O6, O2

2. Explore: Drag each molecule from the MOLECULES pane to the chloroplast on the PHOTOSYNTHESIS pane. If a molecule is an input, it will stay in the chloroplast. Which molecules are inputs in photosynthesis? H2O, CO2

3. Observe: Click Add light and look at the Output. What are the outputs of photosynthesis? C6H12O6, O2 4. Summarize: Although photosynthesis is a complex process involving many reactions, it can be summarized by a simplified formula that shows inputs on the left and outputs on the right. Based on your observations, write a simplified formula for photosynthesis: CO2 + H2O  C6H12O6 + O2 Turn on Show input/output formula to check. Were you correct? Yes

5. Challenge: To balance the inputs and outputs of photosynthesis, there should be the same number of carbon, oxygen, and hydrogen atoms on each side of the arrow. A. Is the formula balanced as written? Why or why not? No it is not balanced because there is an unequal number of H, C and O atoms (more on the right).

B. Now balance the input/output formula by adding coefficients to each molecule. Write the balanced formula below, and then check your work by clicking Balance. 6CO2 + 6H2O (there is also light)  C6H12O6 + 6O2

Activity B:

Get the Gizmo ready:

Cellular respiration

 Click Reset.  Select the RESPIRATION tab.

Introduction: Cellular respiration occurs in the cytoplasm of the cell and in mitochondria, organelles found in all complex cells. (Bacteria and other simple organisms do not contain mitochondria.) The Gizmo shows a mitochondrion surrounded by yellow cytoplasm. Question: What are the inputs and outputs of cellular respiration? 1. Predict: Of the molecules shown on the MOLECULES pane, which do you think are inputs (ingredients) in cellular respiration? Which do you think are outputs? Inputs: C6H12O6, O2

Outputs: CO2, H2O

2. Explore: Drag each molecule from the MOLECULES pane to the RESPIRATION pane. Which molecules are inputs in cellular respiration? C6H12O6, O2

3. Observe: Click Next. What happens in the cytoplasm? The glucose molecule turns into two pyruvate molecules and this process releases energy This process is called glycolysis. Two pyruvate (C3H3O3–) molecules are produced in glycolysis. The released energy is used to form a net of two ATP (adenosine triphosphate) molecules. Energy is later released when ATP molecules are broken down.

4. Observe: Click Next. What happens now? The pyruvate molecules enter the mitochondrion

5. Observe: Click Next. What happens in the mitochondrion? Water, Carbon dioxide and a lot of energy are released. Energy from the mitochondrion is also stored in the form of ATP. A net of 30 ATP molecules are produced for every two molecules of pyruvate.

6. Analyze: Cellular respiration involves two phases. The anaerobic phase does not involve oxygen, while the aerobic phase does. Where does each phase take place? Anaerobic: Cytoplasm Aerobic: Mitochondrion (Activity B continued on next page)

Activity B (continued from previous page) 7. Summarize: Based on what you have seen, write a simplified formula for cellular respiration. C6H12O6 + O2  H2O + CO2 + ATP Turn on Show input/output formula to check. Were you correct? Yes

8. Challenge: To balance the inputs and outputs of cellular respiration, there should be the same number of carbon, oxygen, and hydrogen atoms on each side of the arrow. A. Is the formula balanced as written? Why or why not? It is not balanced because there is an uneven amount of C, H, and O atoms (more on left side) B. Now balance the input/output formula by adding coefficients to each molecule. Write the balanced formula below, and then check your work by clicking Balance. C6H12O2 + 6O2  6H2O + 6CO2 + ATP 9. Compare: The aerobic phase of cellular respiration in the mitochondrion produces a net of about 28 to 30 ATP molecules. How does this compare to the energy released in glycolysis? Glycolysis releases a small amount of ATP. There are 4 molecules of ATP that get synthesized but two of them are used so there is a net release of two ATP. This is much smaller when compared to the net release of 28 to 30 ATP molecules in the aerobic phase of cellular respiration. (Note: Some textbooks state that up to 36 ATP molecules are produced in this phase of cellular respiration. In reality, some energy is lost in the process due to the cost of transporting molecules and imperfect membranes.)

10. Extend your thinking: When you think of the word “respiration,” you might think about the process of breathing, which is actually called ventilation. (The respiratory system consists of the windpipe, lungs, etc.) How is breathing related to cellular respiration? (Hint: Think about both the inputs and the outputs of cellular respiration.) Breathing would be related to cellular respiration because when we inhale, we are going to be taking in oxygen and according to the formula for cellular respiration – this will be one of the reactants. When we exhale we will release CO2 and water (in gas form) which are both products in cellular respiration.

Activity C: The carbonoxygen cycle

Get the Gizmo ready:  Click Reset.  Select the CYCLE tab.

Question: How is photosynthesis related to cellular respiration? 1. Form a hypothesis: How do you think photosynthesis is related to cellular respiration? Photosynthesis is the opposite reaction of cellular respiration and vice versa. The reactants of one will be the products of another and the products of one will be the reactants of the other.

2. Predict: Look at the red arrows, and think about the photosynthesis and respiration processes. Each red arrow connects a set of inputs to the outputs of the reaction. A. Which molecules would you expect to find at the top of the diagram? Explain. I would expect to find glucose and oxygen and the top part because both of these molecules will be products and reactants (product of photosynthesis, reactant of cellular respiration)

B. Which molecules would you expect to find at the bottom of the diagram? Explain. I would expect to find Water and Carbon dioxide at the bottom of the diagram because both will be products in cellular respiration and reactants in photosynthesis.

3. Observe: Drag the Oxygen, Glucose, Carbon dioxide, and Water into the CYCLE pane. A. Which substances are inputs in photosynthesis? CO2 and H2O B. Which substances are outputs of photosynthesis? C6H12O6 and O2 C. Which substances are inputs in respiration? C6H12O6 and O2 D. Which substances are outputs of respiration? CO2 and H2O

4. Compare: How are the inputs and outputs of photosynthesis and respiration related to one another? The reactants of photosynthesis are the products of cellular respiration and the products of photosynthesis are the reactants of cellular respiration (Activity C continued on next page)

Activity C (continued from previous page) 5. Review: In photosynthesis and respiration, energy is converted from one form to another. Light is a form of radiant energy. Glucose and ATP molecules store chemical energy. A. During photosynthesis, what role is played by the radiant energy of the Sun? Explain your answer. During photosynthesis plants are going to trap light energy received from the sun into their leaves. The energy levels from this will activate or excite electrons so that they can be passed along and they will use this energy in order to change carbon dioxide and water to glucose. B. In photosynthesis, what form of energy is sunlight converted to, and how is this energy stored? Photosynthesis is going to convert radiant energy into chemical energy which will then be stored as glucose.

C. Does cellular respiration result in a net input of energy or a net output of energy? Explain. There will be a net output of energy because energy stored as glucose is converted to ATP then is released to be utilized by cells. D. How is the energy produced by respiration stored? The energy produced by respiration is stored as ATP.

6. Summarize: How are respiration and photosynthesis related to each other? As stated above, these two chemical processes will be related because they are the opposite of each other. Photosynthesis will use water, carbon dioxide and light to produce glucose and oxygen, and Cellular Respiration will use glucose and oxygen to produce water, carbon dioxide and energy.

7. Think and discuss: In what ways are plants and animals dependent on each other? There are various things plants and animals depend on one another for. Animals will depend on plants to be a source of food and oxygen or maybe in shelter (small bungs or insects who live on plant leaves etc. Plants will depend on animals for carbon dioxide and in some cases, they will also depend on them for water....