Volume 6, Spring 2008 - Saddleback College

Fall 2007 Biology 3A Abstracts
bouts of exercise result in an accumulation of lactate,
that accumulation has not been directly related to
fatigue or performance.
Traditionally, lactate was considered to be a
waste product resulting in fatigue. Previous studies
have shown that the detrimental effects of elevated
[La - ] may be due more to [H + ] and [K + ]. Although
[H + ]’s role in the onset of fatigue is highly debatable,
the role of the [K + ] on fatigue seems to be more well
documented. Nielsen, 2003, determined that muscle
fatigue during exercise is caused, at least in part, by
high interstitial potassium levels. Here again, [La - ]
and lactic acid may help to maintain a proper [K + ]
balance, reducing fatigue (Gladden, 2004).
Although performance was not improved by
La - supplementation, negative effects of a high [La - ]
were also absent. During short-bouts of near maximal
intensity exercise, blood [La - ] has no effect on
performance. The findings in this research are
consistent with others in that the contribution of [La-]
to fatigue is insignificant (Alhborg, 1986; Ahlborg,
1982; Gladden, 2004; Bangsbo, 1993). High [La-]
associated with fatigue in other studies may have to
do with other factors such as decreased ability of the
body to undergo gluconeogenesis effectively.
Ahlborg, G., Felig, P. (1982). Lactate and glucose
exchange across the forearm, legs, and splanchnic
bed during and after prolonged leg exercise. Journal
of Clinical Investigation, 69, 45-54.
Gladden, L. B. (2004). Lactate metabolism: A new
paradigm for the third millennium. Journal of
Physiology, 558.1, 5-30.
Bangsbo, J., Johansen, L., Graham, T., Saltin, B.
(1993). Lactate and H + effluxes from human skeletal
muscles during intense, dynamic exercise. Journal of
Physiology, 462, 115-133.
Bangsbo, J., Aagaard, T., Olsen, M., Kiens, B.,
Turcotte, L. P., Richter, E. A. (1995). Lactate and H +
uptake in inactive muscles during intense exercise in
man. Journal of Physiology, 488.1, 219-229.
Nielsen, J. J., Mohr, M., Klarkov, C., Kristensen, M.,
Krustrup, P., Juel, C., Bangsbo, J. (2003). Effects of
high-intensity intermitten training on potassium
kinetics and performance in human skeletal muscle.
Journal of Physiology, 554.3, 857-870.
Literature Cited
Alhborg, G., Wahren, J., Felig, P. (1986). Splanchnic
and peripheral glucose and lactate metabolism during
and after prolonged arm exercise. Journal of Clinical
Investigation, 77, 690-699.
The Effect of Silver Nitrate on the Inhibiting Growth of Escherichia coli
Stephanie Anstadt and Teo Fernandez
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
During this experiment the effect of silver nitrate on the inhibition growth of
Escherichia coli was studied. An agar solution was made and placed into a total of fifteen
petri dishes. For this experiment a 0.5% silver nitrate solution was made from a 1.0%
solution and were both used for this study. A controlled group with no silver nitrate
solution was used. 0.5mL of E. coli were pipetted with a P1000 micro pipette and
incorporated into the agar from which a lawn was made. The corresponding silver nitrate
solution was incorporated into each correctly labeled petri dish by using chads. All dishes
were placed into a 37°C incubator and results were read every 48 hour period. The
hypothesis being tested in this experiment was supported by the results obtained during the
second 48 hour period in which p= 0.008.
Introduction By conducting this experiment the
investigators were able to achieve a better
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Saddleback Journal of Biology
Spring 2008