Biology Forum Cell Biology fermentation

last updated by MrMistery 18 years ago
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    • #6316
      wrahma1
      Participant

      hi,
      i recently conducted an experiment testing the effects of pH of three sugars (glucose, sucrose, lactose) on carbon dioxide production rates (i.e. rate of fermentation). the pH levels tested were 3, 7 and 11 respectively (for each sugar, therefore nine experiments were carried out). In all three sugars, the rate of carbon dioxide was highest at pH 7, lowest at pH 11. I am reallllly having difficulty explaining why that is. I know that the optimal pH of enzymes is from 6.5 to 7.5. He told us to explain this biologically, from perspective of enzyme catalyzed reaction and i seriously have no clue where to start explaining. ive been looking for info on this for hours. any help would be greatly appreciated!
      thanks!

    • #60412
      MrMistery
      Participant

      well, seems you already know the answer. the optimal pH for the activity of glycolysis enzymes is 7, and obviously it is not uniform. think of it as a curve, with the peak at 7, and which is more steep in the basic side than in the acidic side. the reason it evolved to tolerate a slight acidic pH better than a slight basic pH is probably because the organism itself produces some acid even when placed in pH 7, so it "evolved used to pH a little lower than 7". however, there is evolutionary reason why an enzyme active in a basic environment would be favorable in these conditions..
      Hope it is clear now

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