Saddleback Journal of Biology - Saddleback College

Spring 2010 Biology 3A Abstracts
10. PH LEVELS OF CRASSULA OVATA GROWN UNDER RED LIGHT AND BLUE LIGHT. Jessica
Dizon and Shabnam Sadat Department of Biological Sciences, Saddleback College, Mission Viejo, CA
92692, USA
Crassula ovata, more commonly known as the Jade plant undergoes a carbon fixation in a process
known as crassulaccean acid metabolism (CAM). In order to prevent water loss Crassula ovata close
their stomata during the day when they utilize the Calvin cycle; at night they undergo carbon fixation. pH
levels are lowest, most acidic, just before daylight. This experiment investigated the effect of red and
blue light on pH levels in Crassula ovata. It was hypothesized that the plants held under blue light would
have a lower pH than those held under red light. The average pH of the leaves after 12 hours of red light
exposure was 4.1 0.2 ( se; N=20) and the average pH after 12 hours of dark was 3.4 0.2 ( se;
N=20). The average pH of the leaves after 12 hours of blue light exposure was 4.1 0.2 ( se; N=20) and
the average pH after 12 hours of dark was 3.4 0.2 ( se; N=20). There was no significant difference
between the leaves grown under red light and under blue light.
11. GROWTH OF MOLD (Penicillium notatum) IN RESPSECT TO pH. Jasmine Singh and Donna
Tehrani. Department of Biological Sciences, Saddleback College, Mission Viejo, CA 92692, USA
A sample of the mold Penicillium notatum was tested for growth, in terms of colonies produced, in a
nutrient-rich media at various pH levels. P. notatum was cultivated on potato dextrose agar plates of three
pH levels 5, 7 and 9 at 24 o C for 2 days. Since the mold has a more basic pH, it was expected that less
growth would occur on the slightly acidic medium and thus produce more colonies on the slightly basic
medium. Mean values of colonies present were 74.67 ± 1.06, 77 ± 1.01, and 79.33 ± 0 .62 (± se) for the
pH levels of 5, 7 and 9 respectively. A one-tailed test showed no significant difference between growth at
low and neutral pH (p = 0.07); however, a significant difference in growth was seen between neutral and
high pH (p = 0.04). Thus, we conclude that this lends support to our initial hypothesis.
12. THE EFFECT OF HYDRATION ON BLOOD GLUCOSE LEVELS. Charlie Paine and Kate Wang.
Department of Biological Sciences, Saddleback College, Mission Viejo, CA 92692, USA
Some diabetics insist they can regulate their blood sugar levels by staying well hydrated. We
predicted that a well-hydrated human would have overall lower blood glucose levels than a non-hydrated
human. The effect of hydration on blood glucose levels in humans was tested in this experiment. All
participants (N=17) started the experiment with a fasting blood sugar level and were given 50 grams of
sucrose in solution. The experimental group (N=9) was also given one liter of water. The control group
(N=8) did not receive any additional water. Blood glucose levels were checked at three intervals
throughout the experiment with a standard diabetic blood glucose meter (mg/dL). The mean change in
blood glucose levels for the hydrated group was 30.8 ± 10.8 mg/dL (±se). The mean change in blood
glucose levels for the control group was 24.9 ± 11.2 mg/dL (±se). The results indicated there was no
significant difference in blood glucose regulation between the experimental and control groups (p=0.45,
one-tailed unpaired t-test).
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Saddleback Journal of Biology
Spring 2010