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Yeast PDF

Laya Pullela conducted an experiment to determine the effect of different colored LED lights on the respiratory patterns of yeast. An apparatus was built to measure the carbon dioxide production of yeast exposed to white, green, blue, red light or no light over 20 minute intervals. The results showed that white light stimulated the highest CO2 production, while green and blue light slightly inhibited it. Red light and no light had similar effects. This demonstrates that certain light frequencies can stimulate the cytochrome c oxidase enzyme and affect metabolic processes, with implications for light therapy applications.

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Niya Shirin
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18 views1 page

Yeast PDF

Laya Pullela conducted an experiment to determine the effect of different colored LED lights on the respiratory patterns of yeast. An apparatus was built to measure the carbon dioxide production of yeast exposed to white, green, blue, red light or no light over 20 minute intervals. The results showed that white light stimulated the highest CO2 production, while green and blue light slightly inhibited it. Red light and no light had similar effects. This demonstrates that certain light frequencies can stimulate the cytochrome c oxidase enzyme and affect metabolic processes, with implications for light therapy applications.

Uploaded by

Niya Shirin
Copyright
© © All Rights Reserved
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Download as PDF, TXT or read online on Scribd
Download as pdf or txt
Download as pdf or txt
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CALIFORNIA SCIENCE & ENGINEERING FAIR

2018 PROJECT SUMMARY

Name(s) Project Number


Laya S. Pullela
S0519
Project Title
The Effect of Colored LED Lights on the Respiratory Patterns in
Saccharomyces cerevisiae
Abstract
Objectives/Goals
This project explores how different colors of LED lights affect the carbon dioxide production in yeast
during the fermentation process, thus determining if certain frequencies of visible light stimulate the
cytochrome c oxidase activity in mitochondrial organisms, which is an essential process for the efficacy of
light therapy.
Methods/Materials
To perform the experiment, a homemade apparatus was built. This apparatus included a large bucket of
water, in which an inverted graduated cylinder filled with water was placed. A vinyl tube was pushed all
the way up the cylinder until it peaked above the water. This tube ran down through the cylinder and out
of the water bucket, and connected to a glass flask which contained the metabolizing yeast. When the
yeast respired, the gas produced would go through the tube and displace the water in the graduated
cylinder. The yeast mixture included dry active yeast, granulated sugar, and water at about 38 degrees
Celsius. The CO2 levels were measured in 4 minute intervals for a total of 20 minutes per trial. 5 trials per
colored light/control.
Results
The results showed that white light actually enhanced the CO2 production in the yeast, producing a mean
of 49.2 mL of CO2, while green and blue light slightly inhibited it (41.7 and 43.4 mL, respectively). The
control experiment (no light), yielded the same results as the red light trials, about 45 mL CO2. The
carbon dioxide production however, did not oscillate, but this may have been because of the short amount
of time in which the experiment was conducted.
Conclusions/Discussion
White light had the best effect on the metabolism of the yeast. This is most likely because white light
emulates sunlight, which is what the organism is naturally exposed to. Red light, unlike hypothesized, did
not enhance the CO2 production in the yeast. However, blue and green light inhibited its metabolism. The
oscillations were expected to reveal the circadian rhythms of the yeast, however, due to the short span of
the experiment, this phenomenon was not observed. Applications of this data include light therapy, which
could possibly revert to LED lights instead of lasers to treat various medical conditions, as LED light has
proven to stimulate the cytochrome c oxidase enzyme (the primary photoreceptor) in the mitochondria of
organisms, thus achieving the same effects as expensive lasers.

Summary Statement
LED light stimulates the cytochrome c oxidase enzyme in the mitochrondria of organisms, thus enhancing
metabolic efficiency.

Help Received
My father helped me in designing my apparatus.

Ap2/18

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