Flashcards in Cellular Respiration Deck (7)
What is methyl blue used as in this experiment?
- artificial electron acceptor
= outcompetes oxygen
-> as a result, methyl blue becomes reduced when it accepts electrons and will change colour
Design & conduct an experiment to test the release of carbon dioxide as a product of respiration
- Place 5 fresh seeds in a test tube
- Place 5 boiled seeds in another tube
- Add 10ml distilled water to both test tubes
- Add 4 drops phenol red solution into each of the test tubes
- Cover each test tube with parafilm and invert each test tube to ensure mixing of the solution
- Place the test tubes in the beaker filled with water (this will act as a temperature control) and leave in a dark room for a significant period of time
- Observe and record any colour changes in a table
- Repeat observations and write down results in table
Why was one of the yeast solutions heat treated?
- to denature the proteins & enzymes within the yeast
= serves as a control
Why was it important to record the time when the contents were initially mixed?
- Rxn starts to occur from that moment
= allows for accurate readings to be taken every 10 min => reference (starting time) remains accurate
Do you think that temperature is a variable that could affect the rate of the reaction?
- increase temp. = increase kinetic energy of particles = increase reaction rate -> more particles collide per unit time
- if temp. Too high = denature enzymes & proteins = decreases rxn rate
What is the role of sodium citrate in the second test tube?
- 6 carbon compound that serves as a catalyst = increase rxn rate
Why were the seeds boiled?
- denature enzymes and proteins in seeds
- allows seeds to be used as a control