Cellular Respiration Lab Report

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Blending a sample of meat will break down the substance, but will not make the liquids the same throughout. Homogenization turns the liquids into a state consisting of extremely small particles that are distributed evenly throughout the substance. After spinning the tubes at 1,000 RCF, or 3,900 RPM, the pellet is likely rich in nuclei and cell debris. The pellet was white/yellow in color, possibly due to precipitated proteins or polynucleotides.

A standard curve is used to measure the final absorbance in samples that have been processed the exact same way. Sample protein concentrations are determined by comparing their assay responses to a series of dilution standards whose concentrations are known. Pyruvate oxidation, and oxidative phosphorylation are represented by the proteins in the samples. There was not much of a difference in the quantity of proteins between the dark and white meat. This is likely due to the fact that some of the sample was spilled during resuspension. This was the only flaw in the experiment.

Dark meat is naturally darker in color, because it is located in the chicken’s wings and legs. Because the chicken is continuously moving these parts, more cellular energy is being used, resulting in more mitochondria. White meat is housed in the chest cavity, which is not moving independently. The white meat does not experience much cellular energy, resulting in less mitochondria.

Conclusion

This lab allowed students to compare the quantity of mitochondrial protein between the preparations of white and dark muscle from chickens by utilizing a centrifuge to complete cell fractionation. The Bradford Assay Curve was used to compare the amounts of protein. The hypothesis- The dark meat of chicken will have the more mitochondrial protein than the white meat, because dark meat uses more cellular energy- was not supported by the data. However, the hypothesis was scientifically correct, and therefore means that there must have been an error in the experiment. There could have been contamination of some sort, or perhaps the chicken that was used in the experiment had gone bad.

References

Areda, D., Boyles, R., Francis, G., & Hite, A. (2016). Laboratory manual for General Biology I. Retrieved from http://lc.gcumedia.com/bio181l/laboratory-manual-for-general-biology-i/v1.1/

[Bio101] Bradford Protein Assay. (n.d.). Retrieved February 17, 2017, from http://www.bio-protocol.org/e45

Khan Academy. (n.d.). Retrieved February 16, 2017, from https://www.khanacademy.org/science/biology/cellular-respiration-and-fermentation#overview-of-cellular-respiration-steps