Name: fret as a molecular ruler in cells
Uploaded: 2023-04-30T06:31:47.000Z
Duration: 6 min 39 s
Channel: JoVE

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Physical Science

HS. Waves and Electromagnetic Radiation

HS-PS4-5.

F&#246;rster Resonance Energy Transfer (FRET)

弗örster共振能量转移（FRET）是一种用于研究短程生物化学相互作用的现象。在FRET中，如果供体光致发光分子的发射光谱与受体分子的吸收光谱存在重叠，则供体分子可通过非辐射方式将能量转移给受体分子。所转移能量的多少——从而样品的整体发射强度——取决于一对光致发光分子（供体与受体）之间的接近程度。FRET分析常与其他生物化学技术结合使用，以从这种“光谱尺”中获取生物大分子结构和相互作用的详细信息。
本视频介绍了FRET分析的原理和概念。实验流程重点介绍FRET样品的制备方法，以及数据的展示和解读方式。最后，应用部分包括通过标记细胞或蛋白质的特定区域来监测构象变化和细胞内过程、监测改变蛋白质结构的酶促反应，以及利用FRET监测细胞表达的单体聚集过程。

förster共振能量转移（fret）

弗örster共振能量转移（FRET）是一种用于研究短程生物化学相互作用的现象。在FRET中，如果供体光致发光分子的发射光谱与受体分子的吸收光谱存在重叠，则供体可非辐射地将能量转移给受体分子。所转移能量的多少——从而样品的整体发射强度——取决于一对光致发光分子（供体与受体）之间的接近程度。FRET分析常与其他生物化学技术结合使用，以从这种“光谱尺”中获取生物大分子结构和相互作用的详细信息。
本视频介绍了FRET分析的原理和概念。实验流程重点介绍FRET样品的制备方法，以及数据的呈现和解读方式。最后，应用实例包括通过标记细胞或蛋白质的特定部分来监测构象变化和细胞内过程、监测改变蛋白质结构的酶促反应，以及利用FRET监测细胞表达的单体聚集过程。
<div class="chapter_text" id="script_0">
弗örster共振能量转移（Förster Resonance Energy Transfer，简称FRET）是一种在发光分子之间发生的非辐射性能量转移，常用于研究短距离的生化相互作用。FRET仅在荧光分子间距小于10 nm时发生。FRET分析可与其他技术结合，以获得详细的结构信息。本视频将介绍FRET的基本原理，概述其实验方案与数据呈现方式，并讨论其在生化研究中的一些应用。
</div>
<div class="chapter_text" id="script_1">
一种光致发光分子（例如荧光团）通过吸收其吸收光谱范围内特定波长的电磁辐射而被激发。在弛豫过程中，它会发射出位于其发射光谱范围内的波长的光。有关荧光的更多信息，请参见 JoVE 关于荧光显微镜的视频。不同的荧光团在不同波长处吸收和发射光，这些波长经常存在重叠。如果一个荧光团的发射光谱与另一个荧光团的吸收光谱显著重叠，则“供体”会释放一个虚光子，该光子被“受体”吸收。当被激发的供体与受体之间的距离在10 nm以内时，能量通过偶极-偶极相互作用从供体传递到受体。相应地，供体通过发光释放能量的过程会减少。与此同时，被激发的受体会在其发射波长处发射光。FRET（荧光共振能量转移）效应通过效率来评估，即供体通过FRET而非荧光或其他辐射过程释放能量的百分比。该效率强烈依赖于供体与受体之间的距离，因此FRET可作为一种“分子”或“光谱”尺子。
在生物化学中，FRET常用于定性观察分子构象变化，通过监测荧光团彼此进入或离开FRET作用范围时的行为来实现。类似地，可通过含有FRET对的分子来研究细胞功能。如果标记的分子被酶活性切割，FRET将停止，观察到的荧光波长随之发生变化。
现在您已了解FRET背后的原理，接下来我们将概述一个实验方案，并介绍几种数据呈现与解读方法。
</div>
<div class="chapter_text" id="script_2">
实验前，通常使用分子生物学技术将感兴趣的生物分子（如 DNA 或蛋白质）进行荧光标记。&#160;将修饰后的遗传物质导入细胞的常用方法包括转染和电穿孔。
随后，将细胞进行准备，以便在荧光显微镜下进行 FRET 观察。&#160;例如，分子可被固定在载玻片上用于单分子 FRET 实验，或样品被加载至微孔板中用于高通量筛选。
接着，准备激发激光器、显微镜及相关设备。（A）FRET 实验常涉及高功率激光器；（B）因此应使用适当的个人防护装备和安全操作规程。&#160;然后将样品置于仪器中，并用激发激光照射。
</div>
<div class="chapter_text" id="script_3">
在监测细胞行为的实验中，常使用彩色图像来显示发射强度的差异或变化。通过将供体和受体的发射强度绘制成图，可追踪随时间变化的FRET响应。
FRET数据也可拟合到多种函数中，以进行更复杂的分析。根据实验的不同，数据可通过多种方式呈现，以最准确地反映实验结果，这使得FRET成为一种灵活的实验工具。
</div>
<div class="chapter_text" id="script_4">
现在您已经熟悉了进行和分析FRET实验的基本方法，接下来让我们看看FRET在生物化学研究中的一些应用。
可通过使用FRET荧光对标记蛋白质或细胞中预测在10 nm范围内相对移动的区域，利用FRET研究构象变化或细胞过程。例如，通过用一对荧光染料标记受体来制备蛋白质传感器，然后利用共聚焦显微镜实时监测FRET信号。发射波长和强度的变化可指示构象改变。
也可通过构建含有活性FRET对的分子并观察其响应变化来应用FRET。当底物被切割时，FRET被破坏，导致供体荧光增强而受体荧光减弱。通过分析发射信号，可分别确定供体、受体及FRET的贡献。一旦计算出青色和黄色荧光蛋白的直接发射因子，即可确定底物的浓度和动力学参数。
设计为表达含有FRET荧光对中任一成员的单体细胞，可作为这些单体间相互作用的“传感器”。若这些单体发生聚集，则可观察到FRET信号。该方法可用于研究由错误折叠蛋白“接种”所引发的蛋白质聚集。在此实验中，细胞被导入目标蛋白的聚集体，经孵育后通过流式细胞术进行分析。
</div>
<div class="chapter_text" id="script_5">
您刚刚观看了 JoVE 关于荧光共振能量转移（Förster Resonance Energy Transfer，简称 FRET）的视频。本视频涵盖了 FRET 的基本原理、FRET 实验的准备与分析方法，以及一些生物化学领域的应用实例。
感谢观看！
</div>

Förster共振能量转移（FRET）

Förster共振能量转移（FRET）是一种用于研究短程生化相互作用的现象。在FRET中，一个供体光致发光…

弗örster共振能量转移（Förster Resonance Energy Transfer，简称FRET）是一种发生在发光分子之间的非辐射性能量转移过程，常用于研究短距离内的生化相互作用。FRET仅在荧光分子间距小于10 nm时发生。FRET分析可与其他技术结合，以获得详细的结构信息。本视频将介绍FRET的基本原理，概述其实验方案与数据呈现方法，并讨论其在生化研究中的一些应用。一种光致发光分子（如荧光团）通过吸收其吸收光谱范围内特定波长的电磁辐射而被激发。在弛豫过程中，它会发射出位于其发射光谱范围内的波长的光。有关荧光的更多信息，请参见 JoVE 关于荧光显微镜的视频。不同的荧光团在不同波长处吸收和发射光，这些波长经常存在重叠。如果一个荧光团的发射光谱与另一个荧光团的吸收光谱显著重叠，则“供体”会释放一个虚光子，该虚光子被“受体”吸收。当被激发的供体与受体之间的距离在10 nm以内时，能量通过偶极-偶极相互作用从供体传递至受体。相应地，供体通过发射光释放能量的过程会减少。与此同时，被激发的受体会在其发射波长处发射光。FRET响应以效率来评估，即供体通过FRET而非荧光或其他辐射过程释放能量的百分比。该效率强烈依赖于供体与受体之间的距离，因此FRET可作为一种“分子”或“光谱”尺。 在生物化学中，FRET 常被用于定性观察分子的构象变化，通过监测荧光基团之间进入或离开 FRET 作用范围的距离变化来实现。类似地，可通过含有 FRET 供受体对的分子来研究细胞功能。如果标记的分子被酶活性切割，FRET 现象将停止，所观察到的荧光波长随之发生变化。了解了FRET背后的原理后，让我们来看一下实验方案的概述，以及几种数据展示和解读方法。实验前，通常使用分子生物学技术将感兴趣的生物分子（如 DNA 或蛋白质）进行荧光标记。将修饰后的遗传物质导入细胞的常用方法包括转染和电穿孔。然后，将细胞进行准备，以便在荧光显微镜下进行FRET成像。例如，可将分子固定在载玻片上用于单分子FRET检测，或将样品加入孔板中用于高通量筛选。然后，准备激发激光器、显微镜及相关设备。（A）FRET 实验通常涉及高功率激光器；（B）因此应使用适当的个人防护装备（PPE）和安全操作规程。随后将样品放入仪器中，并用激发激光照射。在监测细胞行为的实验中，使用彩色图像来显示发射强度的差异或变化。将供体和受体的发射强度绘于同一图表中，以追踪随时间变化的FRET响应。也可以将FRET数据拟合到多种函数中，以进行更复杂的分析。根据实验的不同，数据可以通过多种方式呈现，以最佳方式展示结果，这使得FRET成为一种灵活的实验工具。现在您已经熟悉了进行和分析FRET实验的基本方法，接下来让我们探讨FRET在生物化学研究中的一些应用。荧光共振能量转移（FRET）可用于研究构象变化或细胞过程，方法是用FRET荧光对标记蛋白质或细胞中预测会相互靠近至10 nm以内的部分。例如，通过用一对荧光染料标记受体来制备蛋白质传感器。利用共聚焦显微镜实时监测FRET信号。发射波长和强度的变化表明发生了构象改变。通过制备含有活性FRET对的分子并观察其响应变化，也可利用FRET技术。当底物被切割时，FRET效应被破坏，导致供体荧光发射增强，受体荧光发射减弱。通过分析荧光发射信号，可区分供体、受体及FRET各自的贡献。在计算出青色和黄色荧光蛋白的直接发射因子后，即可确定底物的浓度和动力学参数。设计用于表达含有FRET配对中任一单体的细胞可作为这些单体之间相互作用的“传感器”。如果这些单体发生聚集，则会观察到FRET信号响应。该方法可用于研究由错误折叠蛋白“接种”所引发的蛋白质聚集。在此实验中，细胞被目标蛋白的聚集体转导，经孵育后通过流式细胞术进行分析。您刚刚观看了 JoVE 关于荧光共振能量转移（FRET）的视频。该视频涵盖了 FRET 的基本原理、FRET 实验的准备与分析方法，以及一些生物化学应用。感谢观看！

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JoVE Science Education

Chemistry

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Biochemistry

生物化学

Förster 共振能量转移 (烦恼)

fret as a molecular ruler in cells

Föster resonance energy transfer, or FRET, is a way to study close-range biochemical interactions using light-emitting molecules. A donor fluorophore can pass energy to an acceptor fluorophore when their emission and absorption spectra overlap. This transfer happens only when the pair is very close together, usually within 10 nm.

Because FRET depends on distance, it is often called a molecular or spectroscopic ruler. The strength of the signal is measured as FRET efficiency, which describes how much donor energy is transferred instead of being released as fluorescence. Researchers use this relationship to learn about biomolecular structure and interactions.

FRET is often used to follow conformational changes in proteins and other cell molecules. It can also help monitor cellular processes when fluorophores move in and out of FRET range. If an enzyme cuts a labeled molecule, FRET stops, and the emission pattern changes.

To run a FRET experiment, the biomolecules of interest, usually DNA or proteins, are engineered with fluorescent tags. Modified genetic material is commonly introduced into cells by transfection or electroporation. The samples are then prepared for visualization on a fluorescence microscope, either by immobilizing molecules on a slide for single-molecule FRET or by loading them into wells for high-throughput screening.

The microscope, lasers, and related equipment are prepared before the sample is illuminated. FRET experiments often use powerful lasers, so proper PPE and safety procedures are important. The sample is then analyzed as donor and acceptor signals are recorded.

FRET data can be shown in different ways depending on the experiment. Color images may show changes in emission intensity in live-cell studies. Donor and acceptor intensities can also be plotted over time, and the results may be fitted to functions for more complex analysis.

FRET has several biochemical applications. Protein sensors can be built by labeling receptors with a FRET pair and tracking changes with confocal microscopy. FRET can also be used to study enzyme reactions that alter protein structure, and the emissions can be analyzed to separate donor, acceptor, and FRET contributions.

Another use is monitoring monomer aggregation in cells. Cells can be designed to express monomers that contain one part of a FRET pair, and aggregation produces a measurable FRET response. This approach can help study protein aggregation triggered by seeding with misfolded proteins, using transduced cells followed by incubation and flow cytometry.

FRET as a Molecular Ruler in Cells

dialysis: diffusion based separation

Dialysis for Buffer Exchange in Biochemistry

Dialysis is a common biochemistry technique for buffer exchange and desalting. It separates molecules by diffusion through a semipermeable membrane, which lets small molecules pass while holding larger biomolecules inside the sample. The membrane is the key part of the setup. Its pores create a molecular weight cutoff, so a membrane such as a 10 kDa membrane usually keeps molecules larger than 10 kilodaltons inside. This cutoff is not exact, because membranes have a range of pore sizes.

enzyme assays and kinetics

Measuring Enzyme Reaction Rates

Enzyme reaction rates can be measured with assays that track how substrate or product levels change over time. Enzymes are proteins, or sometimes RNAs, that speed up chemical reactions by lowering the activation energy needed to start them. They act on a specific substrate and help form a product that supports life processes. Enzymatic reactions are often described in three steps. First, the substrate binds to the enzyme active site and forms an enzyme-substrate complex. That complex can fall...

maldi-tof mass spectrometry

How MALDI-TOF Reads Biomolecules

MALDI-TOF mass spectrometry reads biomolecules by using a laser, a matrix, and a time-of-flight analyzer. MALDI, or matrix-assisted laser desorption ionization, helps fragile molecules keep their structure while they are moved into the mass analyzer. The analyzer then separates compounds based on size and charge. In MALDI, the sample is mixed into a matrix, usually an organic compound with aromatic and conjugated double bonds. A laser pulse strikes the spot, and the matrix absorbs most of the...

tandem mass spectrometry

Tandem Mass Spectrometry for Biomolecule Analysis

Tandem mass spectrometry is used to isolate a biomolecule and break it into smaller pieces so its makeup can be studied. Because biomolecules often have large, complex structures, it can be hard to identify their molecular composition and sequence from a single measurement. By linking mass spectrometers in series, the technique first selects one ion and then analyzes the fragments it produces. The process starts with an ion source that converts the sample into ions. A mass analyzer then...

protein crystallization

Protein Crystals for Structure Analysis

Protein crystals help scientists study protein structure and function. A crystal is a solid lattice made from purified protein molecules. These crystals are useful in structural biology because they reveal details that methods like mass spectrometry and SDS-PAGE cannot show on their own. Protein crystallization is paired with recombinant protein expression and x-ray diffraction to support this work. The process starts with a large amount of very pure protein. Researchers often make that...

chromatography-based biomolecule purification methods

chromatography-based-biomolecule-purification-methods

Protein Purification with SEC and IMAC

Protein purification with size-exclusion chromatography and affinity chromatography helps isolate biomolecules from complex mixtures. These methods are common in biochemistry because purified samples are needed before a biomolecule’s properties and activity can be studied. The video focuses on the principles behind size-exclusion chromatography, affinity chromatography, and immobilized metal affinity chromatography, or IMAC. Size-exclusion chromatography, or SEC, separates molecules by size. A...

two-dimensional gel electrophoresis

Protein Mapping with 2D Gel Electrophoresis

Protein mapping with 2D gel electrophoresis separates complex protein mixtures across two steps. The method combines isoelectric focusing, or IEF, with sodium dodecyl sulfate polyacrylamide gel electrophoresis, or SDS-PAGE. Together, these methods can resolve thousands of biomolecules from a single sample by their isoelectric point and molecular weight. The first dimension is IEF. Each protein has an isoelectric point, or pI, which is the pH where its net charge is zero. Proteins are loaded...

metabolic labeling

Tracking Cell Chemistry with Metabolic Labels

Metabolic labeling tracks cell chemistry by using chemical analogs that cells take up and build into biomolecules. These labels help scientists follow biochemical changes and modifications inside cells. The labeled products can then be studied with tools such as SDS-PAGE and NMR to learn more about metabolic pathways. Several labeling strategies are shown here. Isotopic labeling uses analogs that match the natural molecule but contain uncommon isotopes, such as carbon-13 and nitrogen-15 in an...

electrophoretic mobility shift assay (emsa)

electrophoretic-mobility-shift-assay-emsa

Detecting Protein-DNA Binding by EMSA

Electrophoretic mobility shift assay, or EMSA, is a biochemical method used to detect binding between proteins and nucleic acids. It is also called a gel shift assay. The test compares how a labeled nucleic acid moves through a gel before and after it binds a protein. EMSA is used to see whether a specific protein binds to a specific nucleic acid. First, the nucleic acid is labeled to make a probe. The transcript describes radioactive phosphorus-32 as a common label. The probe is then mixed...

photometric protein determination

Measuring Protein Concentration with Absorbance

Measuring protein concentration with absorbance is a key step in many biochemical assays. Photometric methods use the fact that samples with more light-absorbing material transmit less light. Because concentration and absorption are directly related, this makes it possible to measure an unknown sample. The core idea comes from the Beer-Lambert Law. This law states that the concentration of a light-absorbing species is proportional to its absorbance. The video also introduces the Bradford assay...

density gradient ultracentrifugation

Sucrose Gradient Separation in an Ultracentrifuge

Sucrose gradient separation in an ultracentrifuge is a lab method for isolating cell parts and biomolecules. It uses differences in density to make particles sink or rise in a liquid. A high-speed ultracentrifuge speeds up this process so components can be separated without destroying them. The basic idea starts with a suspension, which is particles mixed in a liquid solvent. Particles that are denser than the solvent sediment, while less dense particles float. A rotor inside the...

co-immunoprecipitation and pull-down assays

co-immunoprecipitation-and-pull-down-assays

Protein Interaction Capture Methods in Cells

Co-immunoprecipitation and pull-down assays are laboratory methods used to capture stable protein-protein interactions. Protein-protein interactions help control many biological functions, but many of them have not yet been identified. These assays are related to immunoprecipitation, which isolates a target protein from a mixed sample using an antibody. In co-immunoprecipitation, or CoIP, an antibody binds the target protein, and that protein is already attached to another protein that the...

reconstitution of membrane proteins

Membrane Proteins in Liposome Models

Membrane proteins can be moved into liposome models so their function can be studied outside a cell. Reconstitution means restoring an isolated biomolecule to a working form. For membrane proteins, that usually means placing a purified protein into an artificial lipid membrane. Cell membranes are made mainly of phospholipids and membrane proteins. The phospholipids form a bilayer with hydrophilic phosphate heads facing water and hydrophobic fatty acid tails facing inward. Some membrane...

f&#246;rster resonance energy transfer (fret)

Föster resonance energy transfer, or FRET, is a way to study close-range biochemical interactions using light-emitting molecules. A donor fluorophore can pass energy to an acceptor fluorophore when their emission and absorption spectra overlap. This transfer happens only when the pair is very close together, usually within 10 nm. Because FRET depends on distance, it is often called a molecular or spectroscopic ruler. The strength of the signal is measured as FRET efficiency, which describes...

surface plasmon resonance (spr)

SPR Biosensors for Tracking Binding Kinetics

Surface plasmon resonance, or SPR, is a way to track biomolecular binding on a label-free biosensor. It is used to measure molecular affinity, kinetics, specificity, and concentration. The method works with a thin metal layer on a prism, where changes in reflected light reveal interactions in real time. SPR sensors use a thin layer of a noble metal on the face of a prism. Light is reflected from the prism-metal interface into a photodetector. At one specific angle, called the surface plasmon...

biochemistry

本系列介绍了常用的纯化方法, 如亲和层析, 以及分析方法, 如 MALDI。此外, 视频展示了评估生物相互作用和功能的方法, 如 co-immunoprecipitation 和代谢标记。

Learn how FRET uses donor and acceptor fluorophores to measure distance, track protein changes, and study enzyme activity in cells.

FRET as a Molecular Ruler in Cells | JoVE K12

Life Science

Structure and Function

HS-LS1-1.

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

HS-LS1-6.

Inheritance and Variation of Traits

HS-LS3-1.

Overview

Principles of FRET

Performing the FRET Experiment

Data Presentation and Analysis

Applications

Summary

Travelling Waves

A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. ...

Wave Parameters

The simplest mechanical waves are associated with simple harmonic motion and repeat themselves for several cycles. These simple harmonic waves can be ...

Equations of Wave Motion

Mathematically, the motion of a wave can be studied using a wavefunction. Consider a string oscillating up and down in simple harmonic motion, having a ...

Graphing the Wave Function

Consider the wave equation for a sinusoidal wave moving in the positive x-direction. The wave equation is a function of both position and time. From the ...

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Velocity and Acceleration of a Wave

A wave propagates through a medium with a constant speed, known as a wave velocity. It is different from the speed of the particles of the medium, which ...

Speed of a Transverse Wave

The speed of a wave depends on the characteristics of the medium. For example, in the case of a guitar, the strings vibrate to produce the sound. The ...

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problem-solving-tuning-of-a-guitar-string

Problem-Solving: Tuning of a Guitar String

In the case of stringed instruments like the guitar, the elastic property that determines the speed of the sound produced is its linear mass density or ...

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Kinetic and Potential Energy of a Wave

All forms of waves carry energy; this is directly visualized in nature. For instance, the waves of earthquakes are so intense that they can shake huge ...

Energy and Power of a Wave

The total energy associated with a wavelength is the sum of the potential energy and the kinetic energy. The average rate of energy transfer associated ...

Interference and Superposition of Waves

When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect ...

Reflection of Waves

When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at ...

Propagation of Waves

When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second ...

Standing Waves

Sometimes waves do not seem to move; rather, they just vibrate in place. Unmoving waves can be seen on the surface of a glass of milk kept in a ...

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Modes of Standing Waves - I

A close look at earthquakes provides evidence for the conditions appropriate for resonance, standing waves, and constructive and destructive interference. ...

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Modes of Standing Waves: II

The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions ...

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Sound Waves

Sound waves can be thought of as fluctuations in the pressure of a medium through which they propagate. Since the pressure also makes the medium&#39;s ...

Sound as Pressure Waves

Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As ...

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Perception of Sound Waves

The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different ...

Speed of Sound in Solids and Liquids

Most solids and liquids are incompressible&#8212;their densities remain constant throughout. In the presence of an external force, the molecules tend to ...

Speed of Sound in Gases

The speed of sound in a gaseous medium depends on various factors. Since gases constitute molecules that are free to move, they are highly compressible. ...

Shock Waves

While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the ...

Echo

The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More ...

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Use mathematical representations to support a claim regarding relationships among the period, frequency, wavelength, and speed of waves traveling and transferring energy (amplitude, frequency) in various media.

HS-PS4-1.

Using GIS to Investigate Urban Forestry

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Urban forests broadly include urban parks, street trees, landscaped ...

Evaluate questions about the advantages of using a digital transmission and storage of information.

HS-PS4-2.

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Concept of Resonance and its Characteristics

If a driven oscillator needs to resonate at a specific frequency, then very light damping is required. An example of light damping includes playing piano ...

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Sound Waves: Resonance

Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical ...

Sound Waves: Interference

Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure ...

Interference: Path Lengths

Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two ...

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The Wave Nature of Light

The nature of light has been a subject of inquiry since antiquity. In the seventeenth century, Isaac Newton performed experiments with lenses and prisms ...

The Electromagnetic Spectrum

The electromagnetic spectrum consists of all the types of electromagnetic radiation arranged according to their frequency and wavelength. Each of the ...

The Quantum-Mechanical Model of an Atom

Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of ...

Quantum Numbers

It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy ...

Interference and Diffraction

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
Interference and diffraction ...

Photoelectric Effect

Source: Yong P. Chen, PhD, Department of Physics &#38;&#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
Photoelectric effect ...

Reflection and Refraction

Source: Derek Wilson,&#160;Asantha Cooray, PhD, Department of Physics &#38; Astronomy, School of Physical Sciences, University of California, Irvine, CA
...

Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model (quantum theory), and that for some situations one model is more useful than the other.

HS-PS4-3.

Electric Charge in a Magnetic Field

Source: Andrew Duffy, PhD, Department of Physics, Boston University, Boston, MA
This experiment duplicates J.J. Thomson's famous experiment at the end of ...

Electromagnetic Fields

Electric fields generated by static charges, often referred to as electrostatic fields, are characteristically different from electric fields created by ...

Electromagnetic Waves

James Clerk Maxwell formulated a single theory combining all the electric and magnetic effects scientists knew during that time, calling the phenomena his ...

Electromagnetic waves are categorized according to their wavelengths and frequencies, giving the electromagnetic spectrum. These waves are classified as ...

Plane Electromagnetic Waves I

The existence of combined electric and magnetic fields that propagate through space as electromagnetic (EM) waves is the most significant prediction of ...

Plane Electromagnetic Waves II

Consider a plane wavefront traveling in position x-direction with a constant speed. This wavefront can be utilized to obtain the relationship between ...

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Propagation Speed of Electromagnetic Waves

Electromagnetic waves are consistent with Ampere&#39;s law. Assuming there is no conduction current Ampere&#39;s law is given as:


Consider a plane ...

Electromagnetic Waves in Matter

Electromagnetic waves can travel in the vacuum as well as in matter. For example light, which is an electromagnetic wave, can travel through air, water, ...

Energy Carried By Electromagnetic Waves

Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun&#39;s ...

Intensity Of Electromagnetic Waves

The energy transport per unit area per unit time, or the Poynting vector, gives the energy flux of an electromagnetic wave at any specific time. For a ...

Momentum And Radiation Pressure

An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because ...

Cardiac Magnetic Resonance Imaging

Source: Frederick W. Damen and Craig J. Goergen, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
In this video, high ...

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An Introduction to Drosophila melanogaster

Drosophila melanogaster, also known as the fruit fly, is a powerful model organism widely used in biological research that has made significant ...

Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter.

HS-PS4-4.

FRET as a Molecular Ruler in Cells

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