The regulation of the Krebs cycle is largely determined by product inhibition and substrate availability. The major eventual substrate of the cycle is ADP which gets converted to ATP. A reduced amount of ADP causes accumulation of precursor NADH which in turn can inhibit a number of enzymes. By adding an inhibitor and then measuring the accumulation of an intermediate, it can then be possible to determine the order or sequence of reactions in the cycle. The following assignment is designed to help you determine the sequence of reactions involved in the Krebs cycle by studying the effects of inhibitors on oxygen consumption.
Open MitochondriaLab in BioLabs Online, and perform experiment described in Assignment 2. As you proceed through the assignment, write down your observations in your lab notebook. Use the information that you have written in your notebook to compose your laboratory report. Click here to download the Lab Report Template [Word Document, 14.7KB]. You may use your text and other library sources to support your analyses. Please be sure to cite correctly all sources in APA format.
Mitochondria Lab Name: Subject: Date of Submission: Abstract All organisms that breath follow the Krebs Cycle. Though most often associated with the production of Adenosine Triphosphate (ATP) through the breakdown of oxygen and glucose, the reality is that other metabolic processes that do not involve oxygen produce molecules that enter into the Krebs Cycle. For example, in glycolysis and beta oxidation, both carbohydrates and fatty acids are converted into acetyl CoA, a product of the first stage of the Krebs Cycle. Similarly, the intermediates from the Krebs Cycle such as acetyl CoA can be used to synthesize other molecules, in this case, fatty acids. By understanding its reaction pathway, one begins to understand the role of intermediates in stimulating the Krebs Cycle, as well as the impact of inhibitors to the entire process. By conducting a series of experiments, the researcher hopes to determine how inhibitors work. In particular, the researcher hopes to discover which of the intermediates (enzymes) in the Krebs Cycle is inhibited by malonate. The results indicate that malonate can inhibit succinate and possibly, glutamate. Keywords: Krebs Cycle, malonate, pyruvate, succinate, malate, glutamate, fumarate Introduction The Krebs Cycle, also known as the Citric Acid Cycle is an integral process among aerobic organisms because this is where adenosine triphosphate (A