practical

• What is the name of the practical being discussed?

  Investigating the rate of dehydrogenase activity
• What variable is being changed in the experiment?

  Ammonium hydroxide
• What is the expected effect of ammonium hydroxide on dehydrogenase activity?

  It may decrease or stop the activity
• What are the two reactions involved in the light-dependent reaction mentioned?

  Photoionization and photolysis
• What does the dehydrogenase enzyme do in chloroplasts?

  Catalyzes reactions involving NADP
• What is DCIP and its role in the experiment?

  It is a redox indicator
• What color does DCIP turn when it is reduced?

  Colorless
• Why is ammonium hydroxide used in the experiment?

  To investigate its effect on enzyme activity
• What is the purpose of the control experiments in the setup?

  To validate the results of the experiment
• What is the purpose of the first test tube in the experiment?

  To serve as a standard for comparison
• What does the foil covering the control experiment demonstrate?

  Light is required for DCIP to decolorize
• Why must the isolation medium be isotonic?

  To prevent osmosis affecting chloroplasts
• What happens to the chloroplasts if the solution is not isotonic?

  They may burst or shrivel
• How does ammonium hydroxide affect the light-dependent reaction?

  It slows down or stops the reaction
• What is the conclusion drawn from the experiment regarding ammonium hydroxide?

  It decreases the rate of dehydrogenase activity
• What are the limitations of the experiment discussed?

  • Subjective endpoint determination
  • Unequal light distribution
  • Incomplete light blocking by foil
• Why must solutions be ice cold during the experiment?

  To reduce enzyme activity that could damage chloroplasts
• What is the significance of the time taken for DCIP to decolorize?

  It measures dehydrogenase activity
• What is the expected outcome when ammonium hydroxide is added?

  No change in DCIP color
• What are the key processes involved in the light-dependent reactions?

  • Photoionization of chlorophyll
  • Photolysis of water
  • Electron release and transfer
• What is the role of NADP in the light-dependent reactions?

  It accepts electrons released during reactions
• How does the experiment relate to the concept of weed killers?

  Ammonium hydroxide inhibits photosynthesis in weeds
• What is the relationship between the light-dependent reactions and the Calvin cycle?

  Light-dependent reactions produce ATP and NADPH for the Calvin cycle
• What is the final product of the light-independent reactions?

  Glucose
• What happens to the electrons during photolysis of water?

  They are released for use in photosynthesis
• How does the setup of the experiment help in understanding enzyme activity?

  It demonstrates the effect of variables on enzyme function
• What is the purpose of using a homogenizer in the experiment?

  To break open plant cells and release chloroplasts
• Why is it important to filter the blended spinach?

  To remove large debris and organelles
• What is the significance of using distilled water in the experiment?

  To ensure no additional ions affect the results
• What does the term "redox indicator" refer to in the context of DCIP?

  It changes color based on electron transfer
• How can the experiment be improved to address its limitations?

  By using multiple light sources for even distribution
• What is the role of light in the light-dependent reactions?

  It provides energy for electron release
• What is the expected outcome if light is not present during the experiment?

  DCIP will not decolorize
• How does the experiment demonstrate the concept of enzyme specificity?

  It shows how dehydrogenase interacts with specific substrates
• What is the main conclusion drawn from the experiment regarding ammonium hydroxide?

  It decreases the rate of dehydrogenase activity
• What is the significance of measuring the time taken for DCIP to decolorize?

  It indicates the rate of dehydrogenase activity
• How does the experiment relate to the broader concept of photosynthesis?

  It explores enzyme activity in the light-dependent reactions
• What is the role of the chloroplasts in the experiment?

  They contain the dehydrogenase enzyme
• Why is it important to have a standard for comparison in the experiment?

  To validate the results and reduce subjectivity
• What could be a potential follow-up experiment based on the findings?

  Testing other electron acceptors on enzyme activity