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### Vocabulary Definitions:

1. Stomata:  

   - Small pores on the surface of leaves that allow gas exchange (carbon dioxide in, oxygen out) and water vapor to escape.

2. Stroma:  

   - The fluid-filled space inside the chloroplast, surrounding the thylakoids. The Calvin cycle occurs in the stroma.

3. Grana/Granum:  

   - Stacks of thylakoid membranes in the chloroplast. A granum is a stack, while grana is the plural.

4. Thylakoid:  

   - Membrane-bound structures within the chloroplast where the light-dependent reactions of photosynthesis occur.

5. Thylakoid space:  

   - The inner space inside the thylakoid membrane, where protons (H+) accumulate during the light reactions.

6. Inner/Outer membrane:  

   - Outer membrane: The outermost membrane of the chloroplast.  

   - Inner membrane: The inner membrane that surrounds the stroma and contains the thylakoids.

7. Pigment molecules:  

   - Molecules that absorb light energy for photosynthesis. The primary pigment in plants is chlorophyll.

8. Chlorophyll:  

   - The green pigment in plants responsible for capturing light energy during photosynthesis.

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### Study Guide Questions:

1. Write out the equation for photosynthesis.

   - The overall chemical equation for photosynthesis is:

   \[

   6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2

   \]

   This shows that carbon dioxide and water, using light energy, are converted into glucose and oxygen.

2. Describe the structure of a chloroplast.

   - The chloroplast consists of:

     - Outer membrane: Surrounds the entire chloroplast.

     - Inner membrane: Surrounds the stroma and contains the thylakoids.

     - Stroma: Fluid-filled space where the Calvin cycle occurs.

     - Grana/Granum: Stacks of thylakoids, where light-dependent reactions take place.

     - Thylakoids: Membrane-bound structures inside the grana that house pigment molecules and are involved in the light reactions.

3. Where do the different stages of photosynthesis take place?

   - Light-dependent reactions: Occur in the thylakoid membranes.

   - Calvin cycle (light-independent reactions): Occurs in the stroma of the chloroplast.

4. Describe each stage and their steps in the process of photosynthesis. What are the general reactants and products of each stage?

   - Light-dependent reactions (occur in the thylakoid membranes):

     - Reactants: Water (H2O) and light energy.

     - Products: ATP, NADPH, and oxygen (O2).

     - In these reactions, light energy is absorbed by chlorophyll, and water is split to release oxygen. Energy is stored in ATP and NADPH, which are used in the next stage.

   - Calvin cycle (occur in the stroma):

     - Reactants: Carbon dioxide (CO2), ATP, and NADPH.

     - Products: Glucose (C6H12O6).

     - This cycle uses ATP and NADPH from the light-dependent reactions to convert carbon dioxide into glucose, which the plant uses for energy.

5. Explain the different roles of photosystem I and photosystem II, and the difference between light and dark reactions.

   - Photosystem II:

     - Located in the thylakoid membrane, Photosystem II absorbs light, which excites electrons. These electrons are transferred to the electron transport chain (ETC), leading to the formation of ATP and NADPH.

   - Photosystem I:

     - Also in the thylakoid membrane, Photosystem I absorbs light and re-excites the electrons from Photosystem II. These electrons help produce NADPH.

   - Light reactions (light-dependent reactions) require light and take place in the thylakoid membrane. They convert light energy into chemical energy (ATP and NADPH) and release oxygen.

   - Dark reactions (Calvin cycle or light-independent reactions) do not require light. They occur in the stroma and use ATP and NADPH from the light reactions to convert CO2 into glucose.

6. How is the Calvin cycle connected to events in Photosystems II and I?

   - The Calvin cycle uses the ATP and NADPH produced by Photosystem II and Photosystem I during the light-dependent reactions. These molecules provide the energy and electrons needed to convert CO2 into glucose in the stroma.

7. Where does the sugar come from when a plant undergoes cellular respiration?

   - The sugar used in cellular respiration comes from glucose, which is produced during photosynthesis in the chloroplasts.

8. Where does the oxygen come from when a plant undergoes cellular respiration? What is the oxygen used for?

   - The oxygen released during photosynthesis comes from the splitting of water molecules in the light-dependent reactions. Oxygen is then released as a byproduct into the air. In cellular respiration, oxygen is used as the final electron acceptor in the electron transport chain to produce water.

9. What is the adaptive significance of C4 and CAM variations on "typical" C3 photosynthesis?

   - C3 photosynthesis: The typical photosynthetic process in most plants, where CO2 is directly fixed into a 3-carbon molecule (3-PGA) in the Calvin cycle.

   - C4 photosynthesis: Found in plants like corn and sugarcane, C4 photosynthesis separates the initial CO2 fixation step from the Calvin cycle, allowing these plants to conserve water and avoid photorespiration in hot, dry climates.

   - CAM photosynthesis: Found in plants like cacti and succulents, CAM photosynthesis involves opening stomata at night to fix CO2, minimizing water loss during the day. This adaptation is useful in arid environments where water is scarce.

---Vocabulary Definitions:

1. Energy:  

   - The capacity to do work or cause change. Energy exists in different forms, such as kinetic, potential, chemical, and more.

2. Work:  

   - The transfer of energy through motion. Work is done when a force causes an object to move.

3. Kinetic Energy:  

   - Energy of motion. For example, a moving car, running, or a bouncing ball all demonstrate kinetic energy.

4. Potential Energy:  

   - Stored energy due to an object's position or structure. For example, a book on a shelf has potential energy due to its height.

5. Chemical Energy:  

   - Energy stored in the bonds of chemical compounds. This energy is released or absorbed during chemical reactions. For example, food and fuel store chemical energy.

6. Free Energy:  

   - The amount of energy available to do work in a system. It’s the energy that can be used by a cell for activities like growth or movement.

7. Activation Energy:  

   - The energy required to start a chemical reaction. It’s like a "push" to get the reaction going.

8. Enzyme:  

   - A protein that speeds up (catalyzes) chemical reactions by lowering the activation energy required.

9. Substrate:  

   - The substance an enzyme acts upon in a chemical reaction. The enzyme binds to the substrate to form a product.

10. Reactants vs. Products:  

    - Reactants: Substances that undergo a chemical reaction.  

    - Products: New substances formed as a result of a chemical reaction.

11. Entropy:  

    - A measure of disorder or randomness in a system. The second law of thermodynamics states that entropy tends to increase over time in a closed system.

12. Calorie vs. calorie:  

    - Calorie (capital C): A unit of energy used in nutrition. 1 Calorie = 1,000 calories.  

    - calorie (lowercase c): A small unit of energy used to measure heat; it’s the amount of energy needed to raise 1 gram of water by 1°C.

13. 1st Law of Thermodynamics:  

    - Energy cannot be created or destroyed; it can only be converted from one form to another. This is also known as the Law of Conservation of Energy.

14. 2nd Law of Thermodynamics:  

    - The total entropy of an isolated system always increases over time, and energy transformations are never 100% efficient. Some energy is always lost as heat.

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### Study Guide Questions:

1. Try to identify several different examples of energy in your daily life and classify them as kinetic or potential.  

   - Kinetic energy: A moving car, running, or a person riding a bike.

   - Potential energy: A book on a shelf, water stored in a dam, or a stretched rubber band.

2. Define chemical energy and explain how it is used.  

   - Chemical energy is the energy stored in the bonds of molecules. Our body uses it to power activities like movement, digestion, and cell function. For example, when we eat food, our body breaks down the food molecules (like glucose) to release chemical energy that we use for daily tasks.

3. Define metabolism and explain the difference between catabolism and anabolism.  

   - Metabolism refers to all the chemical reactions that occur within an organism to maintain life.  

   - Catabolism: The breakdown of larger molecules into smaller ones, releasing energy (e.g., digestion).  

   - Anabolism: The building of larger molecules from smaller ones, requiring energy (e.g., building muscle or DNA).

4. How do we measure the efficiency of a chemical reaction?  

   - The efficiency of a chemical reaction can be measured by how much energy is produced as useful work compared to how much energy is lost as heat. This is often described as the energy yield or efficiency ratio.

5. What does it mean when some energy is dissipated as heat in a chemical reaction?  

   - It means that during the reaction, not all of the energy was used to do work. Some of it was lost as heat energy, making the reaction less efficient. This aligns with the 2nd Law of Thermodynamics.

6. Be able to describe all the energy transformations in the "howling gummy bear" demonstration.  

   - In this demonstration, a gummy bear undergoes a chemical reaction when it reacts with potassium chlorate (KClO₃). The reaction releases chemical energy that is transformed into heat energy, causing the gummy bear to burn and release gases. This leads to an explosive, energy-releasing "howling" effect.

7. Define "activation energy" and be able to describe how enzymes lower activation energy.  

   - Activation energy is the energy required to start a chemical reaction. Enzymes are biological catalysts that speed up reactions by lowering the activation energy, making it easier for reactions to occur at lower temperatures.

8. Be able to describe real applications of the 1st and 2nd Laws of Thermodynamics.  

   - 1st Law (Conservation of Energy): In a power plant, chemical energy in fuel is converted into electrical energy. The total energy is conserved, though some is lost as heat.

   - 2nd Law (Entropy): In a car engine, energy is transformed from fuel into motion, but much of the energy is lost as heat, increasing the system's entropy.

9. What is ATP and how does it work to store energy in cells?  

   - ATP (Adenosine Triphosphate) is the main energy carrier in cells. It stores energy in the high-energy bonds between its phosphate groups. When the cell needs energy, ATP is broken down into ADP (Adenosine Diphosphate) and an inorganic phosphate, releasing energy that the cell can use for work.

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These explanations break down the concepts in simple terms to help you understand the vocabulary and questions about energy and its role in life processes!

These explanations should help clarify the process of photosynthesis and how different plants adapt to their environments!