The Effect of Substrates on Yeast Metabolism
Nicole Rzhemovskiy
Hugh McRoberts Secondary
Floor Location : S 005 H

Based on the World Health Organization (WHO), 1.62 billion people worldwide are affected by anemia - the most-common blood disorder. The group with the highest prevalence of iron depletion is women of childbearing age, including myself. I have suffered from this condition for the past year, and it is the reason why I am investigating this particular issue. Iron-deficiency anemia is often described by not having enough iron-rich hemoglobin. Without iron, the electron transport chain in cells is incapable of creating energy under the form of adenosine triphosphate (ATP); hence, one of the symptoms of anemia is fatigue. People afflicted by this condition typically take oral medication, and it is the solution that I am observing in my experiment.

In this project, I analyze factors that influence the creation of ATP. The chemicals examined are minerals (ferrous iron), combinations of vitamin C and iron, biotin, niacin, and hormones (melatonin). My research concentrates on supplements that are claimed to improve energy yielding metabolism, and some that may not necessarily be proven to have that function. I use yeast to discover which supplement is the most beneficial when it comes to producing the micro-currency of energy. These eukaryotic cells are model organisms, since the electron transport chain is quite similar in both humans and yeast.

In my procedure, methylene blue changes from indigo to clear, when yeast produce carbon dioxide through cellular respiration. Through analyzing the rate of colour change of the various compounds, we can see their impact on the rate of cellular energy production. Since I cannot directly measure ATP, I use a colorimetric analysis instead. The experiment was done on 24 well plates with four replicates of each condition. Some chemicals were examined in combinations. Imaging the colour change was performed by scanning the plates every 5 minutes for 30 minutes. Analysis of the colour in each image was conducted through measuring the RGB pixel intensities in Photoshop.

My purpose is not only to see what factors, but also what combinations are to change colour, as well as their rate of change. My procedure has been extrapolated from previous attempts to measure ATP, but has developed to be relatively more efficient. In my hypothesis, ferrous sulfate should be the most effective substrate in producing energy according to past research. Substrates that act as alternatives should have no or little change in colour visually.