Lesson 6 GRQs Energy and Enzymes and Cellular Respiration PDF

Preview

Summary

Lesson 6 GRQ's answers and questions for Biology 101....

Description

Energy and Enzymes and Cellular Respiration Guided Reading Qs (Do these before the Mastering Assignment.) (Reading 5.10 - 5.16 and 6.1 - 6.6) Reading Objectives:  Differentiate kinetic, potential, and chemical energy. In subsequent lessons, identify how these types of energy relate to cellular respiration and photosynthesis.  Compare and contrast cellular respiration and photosynthesis as energy reactions.  Explain the relationship between ATP and ADP.  Identify functions of enzymes and the conditions they work best at.  Explain how enzyme reactions are inhibited. Explain the purpose of aerobic respiration and name the inputs and outputs. Describe the significance of coenzymes in aerobic respiration. 1. The two basic forms of energy are: a. Potential b. Kinetic Match each type of energy to one of these two forms you listed above: The spinning movement of a protein as protons move through its channels K The energy stored in the chemical bonds of glucose P The release of heat from your body when you exercise. K The sunlight that powers photosynthesis. K Energy in the universe can be transferred or transformed but it cannot be Created or Destroyed. 2. Why is a plant cell thought of as an energy transformer? It converts light energy to chemical energy 3. How is burning fuel in your car or burning wood similar to how your body uses fuel? How is it different? Cars mix oxygen with gasoline to make an explosive chemical reaction that move the car, Cells do the same thing with oxygen while making cellular respiration. Define cellular respiration: The chemical energy stored in organic molecules is used to produce ATP 4. Fill out the table below:

Photosynthesis

Cellular Respiration

List the reactants. Are these “energy-rich” or “energy-poor”? Carbon Dioxide and Water (Poor)

List the products. these “energy-rich” “energy-poor”? Glucose (Rich)

Rich

Poor

5. How do the structures of ATP and ADP differ? 1

Are or

ATP has three phosphates and ADP has two phosphates due to Diphosphate and Triphosphate. 6. How does phosphorylation lead to cellular work? What are examples of “cellular work”? Cellular work often depends on ATP energizing molecules by phosphorylating them. Cellular Work includes chemical, transport and mechanical work of a cell.

7. What does the activation energy of a chemical reaction specifically do to reactants? What do enzymes do to the activation energy? Energy must be absorbed to contort or weaken bonds in reactant molecules so that they can break and form new bonds. It lowers the activation energy. 8. Draw a graph with two lines. One line will represent a reaction without an enzyme and the other will represent an enzyme-catalyzed reaction. Your Y-axis should be labeled as increasing energy and your X-axis should be labeled “progress of reaction”. Be sure to label the activation energy for both reactions.

9. True or False? Defend you answer for each (i.e. state why a particular statement is true or correct a false statement). F Enzymes are consumed in reactions. Enzymes are molecules that function as biological catalysts, increasing the rate of a reaction without being consumed by the reaction. F Enzymes are always proteins. Some RNA molecules also function as enzymes F “Substrate” is another word for reactant. It is a specific reactant that an enzyme acts on T Enzymes are specific They are specifically shaped ___ An enzyme may have multiple types of active sites to bind multiple types of substrates. 10. What conditions do most enzymes work best at? Most human enzymes work best at 35-40C 11. The cereal you ate this week, even if it was Fruit Loops, contained metals found on the periodic chart such as zinc and iron. What are these metals doing in your cereal? And wait…is there a connection between chemistry and biology??? They act as cofactors which bind to active sites and function in catalysis.

11. Examine figure 5.15. Explain in your words what this illustration describes, being sure to define all the vocabulary words from this illustration. 2

12. The books discusses how the same enzyme that transmits nerve impulses can be inhibited in insects and lead to death but when inhibited in a slightly different way in humans can be used as anesthesia for surgical procedures. What is the difference in this inhibition? Insects irreversibly inhibit the specific enzyme whereas humans reversibly inhibit the same enzyme. Chapter 6: Overview of Respiration 1. How does energy cycle through an ecosystem, as shown in Figure 6.1? Photosynthesis  Organic Molecules + O2  Cellular Respiration  CO2, H2O What is different about how matter cycles?

What organisms can perform cellular respiration? Eukaryotic organisms 2. Deep breath in…. deep breath out. How is breathing related to cellular respiration? As a runner breathes in their lungs take up O2 and pass it to their blood. Then their bloodstream carries O2 to her muscle cells where it is used in cellular respiration to produce ATP to power their cells to run faster. What is the chemical equation for cellular respiration? Glucose + O2  CO2 + H2O + ATP Only 34% of the energy is captured from the bonds stored in glucose. What happens to much of the energy originally stored in glucose? Released in heat 3. Late night pizza run in the dorms—you have already eaten plenty for the day so these two slices are “extra” that you promise to burn off tomorrow in the gym with some walking around campus. If each pizza slice is about 475kcal, and you weigh approximately 150lbs, how many hours will you walk around campus at 3mph? 4 hours

3

4. Ultimately electrons are passed from glucose to oxygen. Glucose is oxidized/reduced? Oxygen is oxidized/reduced? What happens to the energy lost through these electron transfers? 5. Co-enzymes are a bit like taxi drivers in the process picking up and releasing electrons. When NAD+ gains electrons from glucose and other molecules, we say it has been oxidized. It is now in the form NADH (it has picked up one proton from hydrogen too). When NADH gives up (loses) these electrons to the electron transport chain we say that this molecule has been substrate-level phophorylation. Let’s end this set of GRQs with the overview of cellular respiration in eukaryotes. Be attentive to details like the color coding that your book uses. You will see these same symbols/colors in the animation too. (Prokaryotes don’t have mitochondria—can they make ATP? Yes or no? Do they have energy needs?) Overview: in a eukaryote A. Stage 1: Glycolysis: occurs where in the cell? Cytosol Glucose is split into two molecules of a 3-carbon compound called pyruvate. Is any ATP made? (yes or no) B. Stage 2: Pyruvate oxidation and Citric Acid Cycle. This takes place where in the cell? Mitochondria Pyruvate is now broken ultimately to CO2 (a one-carbon compound) which you eventually breathe out. Is any ATP made? (yes or no) Stages 1 and 2 importantly supply ____________ (little blue balls) to the third stage. C. Stage 3: Oxidative phosphorylation. Located where in cell? Mitochondrial membrane Is any ATP generated? (yes or no) How does this compare to stages 1 and 2? A lot more is produced.

Tip: Watch the BioFlix animation in the study area of Mastering in this chapter. Then, put it on mute and see if you can narrate it!

4...