Related Experiment Video
Updated: Feb 13, 2026
08:38
A System for Tracking the Dynamics of Social Preference Behavior in Small Rodents
Published on: November 21, 2019
8.2K
Differences in dynamic behavior of single diatom cells caused by changing wavelengths
Hisao Taira1, Shunsuke Kondo2, Yoshikazu Kumashiro3
1Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan; Faculty of Education, Hokkaido University of Education, Sapporo, Hokkaido, 002-8502, Japan.
Micron (Oxford, England : 1993)
|March 3, 2018
Summary
Diatom cell speed is affected by light wavelength, not intensity. Specific wavelengths absorbed by chloroplasts influence diatom motion, crucial for understanding photosynthetic organism behavior.
Area of Science:
- Cell Biology
- Biophysics
- Photosynthesis Research
Background:
- Diatom cells possess chloroplasts containing photosynthetic pigments.
- These pigments absorb specific light wavelengths, including blue (400-450 nm) and red (650-700 nm).
- Light influences the behavior and motion of various microorganisms.
Purpose of the Study:
- To investigate the effect of light wavelength on diatom cell motion.
- To determine if light intensity or wavelength is the primary factor influencing diatom speed.
- To understand the phototaxis response in diatoms related to chloroplast absorption spectra.
Main Methods:
- Diatom cells were irradiated with a halogen lamp at a constant intensity (approx. 500 Lx).
- Colored filters were used to selectively remove blue or red light wavelengths.
- Cellular motion was observed and quantified using optical microscopy.
Main Results:
- Diatom cell speed decreased when specific wavelengths (blue or red light) were filtered out.
- Cell speed increased upon removal of the colored filters, restoring the full spectrum.
- The observed changes in speed occurred at constant light intensity, isolating wavelength as the variable.
Conclusions:
- Light wavelength significantly influences diatom cell speed and motion.
- The effect is independent of light intensity, suggesting a wavelength-specific response.
- This finding highlights the role of photosynthetic pigments in mediating diatom behavior under light stimulation.
Related Concept Videos
02:32The de Broglie Wavelength
33.8K
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
33.8K
01:50Global Climate Change
29.1K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
29.1K
03:00Standard Entropy Change for a Reaction
25.0K
Entropy is a state function, so the standard entropy change for a chemical reaction (ΔS°rxn) can be calculated from the difference in standard entropy between the products and the reactants.
25.0K
02:27Le Chatelier's Principle: Changing Concentration
66.1K
A system at equilibrium is in a state of dynamic balance, with forward and reverse reactions taking place at equal rates. If an equilibrium system is subjected to a change in conditions that affects these reaction rates differently (a stress), then the rates are no longer equal and the system is not at equilibrium. The system will subsequently experience a net reaction in the direction of a greater rate (a shift) that will re-establish the equilibrium. This phenomenon is summarized by Le...
66.1K
01:16Electric Potential and Potential Difference
5.8K
Suppose a positive test charge moves away from a positive static charge, then the Coulomb force does positive work, and its electric potential energy decreases. The potential energy per unit charge is defined as the electric potential. The electric potential is independent of the test charge.
When a test charge moves from the initial to the final position, the electric potential difference between those positions is defined as the ratio of the change in the potential energy to the charge on the...
When a test charge moves from the initial to the final position, the electric potential difference between those positions is defined as the ratio of the change in the potential energy to the charge on the...
5.8K
01:05Difference from Background: Limit of Detection
8.4K
The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals.
The LOD indicates the presence or absence...
The LOD indicates the presence or absence...
8.4K