Question

Use the description below and the ‘Antioxidant enzyme dataset’ to answer question(s) Understanding oxidative stress requires that we understand what triggers the production of antioxidant enzymes within a cell. Studies have shown that yeast cells with high levels of one antioxidant enzyme tend to also have high levels of other antioxidant enzymes. A team of Russian scientists wondered if the enzyme superoxide dismutase (SOD) could trigger the production of catalase. To investigate this, the researchers created a gradient of SOD activity levels by exposing yeast cells to different amounts of an inhibitor of SOD. Thus, some yeast suspensions had higher SOD activity levels than others. After culturing the yeast in YPD media for an hour, the researchers measured catalase activity (U/mg protein) and SOD activity (U/mg protein) in the various yeast suspensions.

What is a reasonable hypothesis for this study?

What is logical prediction, given the study design and hypothesis you developed?

Answer 1

The reasonable hypothesis set for this study is that, the higher concentration of enzyme superoxide dismutase (SOD) is responsible for the increased production of catalase in the cells under oxidative stress.

It was done by designing the experiment where yeast cells were cultured in YPD media at different concentrations of inhibitors for Enzyme SOD, therby changing the concentration of active Enzyme in the cell which in turn lead to the difference in the concentrations of catalase's production.

The logical predictions of the hypothesis developed and the given study design are as follows:-

They found the direct proportional concentration between the two enzymes catalse and SOD activities.

Both the enzyme catalase and SOD acts synergistically to act as free radicle scavengers .SOD acts as antioxidative enzyme that catalyses the dismutation of the highly reactive superoxide anion to O2 and to the less reactive species H2O2. The higher level of this peroxide ions leads to increased activity of catalase and this H2O2 is then converted into water and oxygen molecules by the enzyme catalase.

So, it can be inferred that hypothesis established is somewhat correct and the concentration of SOD affects the concentration of catalse in the yeast cells. And the concentration of one of the antioxidative enzyme can affect the concentration of other antioxidative enzymes.