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Photosynthesis and Cellular Respiration

Prompt

  1. Why are photosynthesis and cellular respiration are opposite processes?
  2. Describe the process of fermentation (for both types)?
  3. Name parts of \(ATP\) and \(ADP\) molecules?
  4. Describe the process of ETC (Electron Transport Chain)?
  5. Where is \(ATP\) synthase located?
  6. Where are H+ (protons) transported to create a gradient for \(ATP\) synthesis?
  7. How does temperature and light affect photosynthesis?
  8. Name 4 steps for ETC?
  9. Name 4 steps for Photosynthesis?
  10. Name reactants and products in light-dependent reaction?
  11. Describe glycolysis?
  12. Reactants and products of the Krebs Cycle?
  13. Compare chloroplast and mitochondria?
  14. Describe CAM plants (read about them first)?
  15. Let's say one mole of glucose contains \(5000 \text{ kJ}\) of energy. The hydrolysis (breaking down) of one mole of \(ATP\) releases \(51 \text{ kJ}\) of energy. Calculate the percentage of energy that is transformed to useful energy in a body. Show your work.

Response

  1. Photosynthesis and cellular respiration are opposite processes. Photosynthesis uses carbon dioxide and water, in the presence of sunlight, to produce glucose and oxygen. On the other hand, cellular respiration uses glucose and oxygen to produce carbon dioxide, water, and energy (\(ATP\)). Essentially, photosynthesis converts light energy into chemical energy, while cellular respiration converts chemical energy into usable energy (\(ATP\)).
  2. There are two main types of fermentation:
    • Alcoholic Fermentation: Occurs in yeast and some types of bacteria. It converts glucose into ethanol, carbon dioxide, and a small amount of energy.
    • Lactic Acid Fermentation: Occurs in certain bacteria and in muscle cells when oxygen is scarce. It converts glucose into lactic acid and a small amount of energy.
  3. Parts of \(ATP\) and \(ADP\) Molecules:
    • \(ATP\) (Adenosine Triphosphate): Composed of the nitrogenous base adenine, the sugar ribose, and three phosphate groups.
    • \(ADP\) (Adenosine Diphosphate): Similar to \(ATP\), but with only two phosphate groups.
  4. Electron Transport Chain (ETC): This is a series of protein complexes and other molecules that transfer electrons from electron donors to electron acceptors via redox reactions. This movement of electrons creates a proton gradient that drives the synthesis of \(ATP\). It's a key step in cellular respiration, occurring in the inner mitochondrial membrane.
  5. Location of \(ATP\) Synthase: \(ATP\) synthase is located in the inner mitochondrial membrane in eukaryotic cells, and in the plasma membrane of prokaryotic cells.
  6. Transport of $\text{H}^+} (Protons): During ETC, protons are transported across the inner mitochondrial membrane (in eukaryotes) or the plasma membrane (in prokaryotes), from the mitochondrial matrix to the intermembrane space, creating a proton gradient.
  7. Effect of Temperature and Light on Photosynthesis:
    • Temperature: Affects the rate of photosynthesis; too low or too high temperatures can slow down or inhibit the process.
    • Light: Essential for photosynthesis; light intensity can influence the rate at which photosynthesis occurs.
  8. Four Steps of ETC:
    • Electron Donation to Complexes
    • Proton Pumping Across Membrane
    • Transfer of Electrons to Oxygen
    • Generation of Proton Gradient for \(ATP\) Production
  9. Four Steps of Photosynthesis:
    • Light Absorption
    • Water Photolysis
    • Carbon Dioxide Fixation
    • Glucose Synthesis
  10. Light-Dependent Reaction Reactants and Products:
    • Reactants: \(H_2O\), light, \(NADP\), \(ADP\)
    • Products: \(O_2\), \(ATP\), \(NADPH\)
  11. Glycolysis: A process where glucose is broken down in the cytoplasm of cells into two molecules of pyruvate. It results in the production of a small amount of energy (\(ATP\)) and reduced NADH.
  12. Reactants and Products of the Krebs Cycle:
    • Reactants: \(\text{Acetyl-}CoA\), \(NAD^+\), \(FAD\), \(ADP\).
    • Products: \(\text{CO}_2\), \(ATP\), \(NADH\), \(FADH_2\).
  13. Comparison of Chloroplast and Mitochondria:
    • Chloroplasts: Found in plants and algae, site of photosynthesis, contain chlorophyll.
    • Mitochondria: Found in most eukaryotic cells, site of cellular respiration, powerhouse of the cell.
  14. CAM Plants: These are plants that use Crassulacean Acid Metabolism (CAM), a specialized form of photosynthesis. CAM plants open their stomata at night to minimize water loss, storing CO2 in the form of an acid before using it for photosynthesis during the day. This adaptation is beneficial in arid conditions. Examples include cacti and some succulents.

  15. The percentage of energy from one mole of glucose that is transformed into useful energy in the form of \(ATP\) in the body is approximately 38.76%. This calculation assumes that one mole of glucose, through cellular respiration, produces about 38 \(ATP\) molecules, and each \(ATP\) molecule releases \(51 \text{ kJ}\) of energy upon hydrolysis.

    \[ E_{glucose} = 5000 \text{ kJ} \\\ E_{ATP} = 51 \text{ kJ} \\\ \text{ATP molecules per glucose} = 38 \\\ \]
    \[ E_{total} = 38 \cdot 51 = 1938 \text{ kJ} \\\ E_{useful} = \frac{E_{total}}{E_G} \cdot 100 = \frac{1938}{5000} \cdot 100 = 38.76\% \]