Video Experimental Relacionado
Updated: Apr 16, 2026
11:24
High Precision FRET at Single-molecule Level for Biomolecule Structure Determination
Published on: May 13, 2017
11.5K
Observación microscópica electrónica de la excitación selectiva del cambio de conformación de una sola molécula
Ricardo M Gorgoll1, Emrah Yücelen2, Akihito Kumamoto3
1†Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|March 4, 2015
Resumen
La microscopía electrónica de transmisión de resolución atómica captura visualmente la relajación de la energía molecular y los cambios conformacionales. Esta técnica ayuda a comprender la dinámica molecular e identificar diferentes estructuras moleculares.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La biofísica molecular es la biofísica molecular.
- Física Química Física Química es la física de la química.
Sus antecedentes:
- Comprender la dinámica de conformación molecular es crucial para predecir las propiedades de los materiales y las funciones biológicas.
- Observar directamente los procesos de relajación de la energía molecular a resolución atómica ha sido un desafío significativo.
Objetivo del estudio:
- Para observar visualmente el proceso de relajación de energía de los conformeros moleculares.
- Investigar la movilidad conformacional e identificar estructuras moleculares utilizando técnicas avanzadas de microscopía.
Principales métodos:
- Se empleó microscopía electrónica de transmisión (TEM) de resolución atómica en diferentes voltajes de aceleración de electrones.
- Se realizó un análisis de correlación cruzada en imágenes secuenciales de TEM y diferencias entre imágenes experimentales y simuladas.
Principales resultados:
- Se obtuvo evidencia visual directa de la relajación de la energía a través de la rotación de la parte molecular.
- Se investigó con éxito la movilidad conformal y las estructuras conformadoras distintas.
Conclusiones:
- La resolución atómica TEM es una poderosa herramienta para visualizar procesos moleculares dinámicos.
- El estudio proporciona nuevos conocimientos sobre los cambios de conformación molecular y los paisajes energéticos.
Videos de Conceptos Relacionados
01:28Cryo-electron Microscopy
4.6K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
4.6K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
1.4K
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
1.4K
01:14Molecular Spectroscopy: Absorption and Emission
5.5K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
5.5K
01:25Overview of Electron Microscopy
16.6K
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
16.6K
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
3.6K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
3.6K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.5K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.5K