Abstract:
This experiment attempts to answer the question of whether an increase in a succinate concentration (a component of the Krebs cycle) will lead to an increased rate of cellular respiration within a cell. We measured the amount of electrons given off by the succinate to fumerate redox reaction by using DPIP. DPIP is an electron acceptor that takes the place of FAD by accepting the electrons and turning from its oxidized blue state to its reduced clear state. We had three tubes with varying concentrations of succinate and measured the transmittance of each over a half hour period to determine whether more succinate led to more DPIP being reduced. The results showed that the tube with no succinate (no reaction) …show more content…
I hypothesized that an increase in succinate concentration would lead to an increase in the amount of the reaction taking place, and I predicted that if the quantity of succinate is increased, then the amount of amount of DPIP reduced would also increase. Based on the evidence collected, it is fair to conclude that an increased amount of succinate does in fact lead to a faster rate of cellular respiration. Since DPIP turns colorless when it accepts electrons and is reduced, less light will be bouncing off of the blue pigment in it, and instead will be transmitted through. Therefore, the tubes with the highest transmittance have the most DPIP being reduced during the conversion of succinate to fumerate. Table 3 shows the tubes with the highest concentration of succinate went up the largest amount in percent transmittance. On the other hand, Table 1 shows that a solution with no succinate, and therefore no reaction, increases very little. As expected Table 2 shows that a solution with a low succinate concentration has a transmittance in between the two extremes. The data supports my hypothesis because the transmittance increase for tube 1 is 1.84%, 14.17% for tube 2, and 26.77% for tube 3. This shows that the tubes with more succinate became clearer than those with less. The …show more content…
My prediction was also supported because raising the succinate concentration did indeed lead to the transmittance raising. While the experiment was effective in producing the results that I expected, errors were made and there was room for improvement. One possible source of error is differing times in between adding the succinate and measuring the transmittance between trials. Ideally, we would’ve placed the completed solution in the spectrophotometer immediately after introducing the succinate. However, this was not possible and the times between adding the succinate and taking the first reading differed among trials. The effect of this is simply that some reactions will have started before others, and some may be farther along when the first and subsequent readings are taken. Another possible source of error is insufficient mixing of the tubes before transmittance readings. Not mixing the tubes properly may allow some of the important elements of the substance to settle at the bottom, giving the tube an inaccurate reading. Improvements on the experiment include more trials for each tube. An increase in trials would enhance the reliability and credibility of the data. Another possible improvement would be to include more succinate concentrations. While, this would require more work, having more tubes with higher concentrations of