Name: protein crystals for structure analysis
Uploaded: 2023-04-30T06:31:18.000Z
Duration: 7 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.

Protein Crystallization

蛋白质结晶

蛋白质结晶，获得一个坚实的格子的生物分子，阐明了蛋白质的结构，并使蛋白功能的研究。结晶涉及干燥组合的许多因素，包括 ph 值、 温度、 离子强度、 蛋白质浓度下的纯化的蛋白。一旦获得晶体，可以通过 x 射线衍射和电子密度模型计算阐明蛋白质结构。
本视频介绍了蛋白质结晶和显示的一般程序。的过程中，涵盖了蛋白的表达和纯化、 结晶和 x-射线衍射。蛋白质结晶的应用包括在硅片药物设计、 绑定现场测定和膜蛋白结构分析。
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蛋白质结晶是获得格构式固体形式的一种蛋白质的过程。这些水晶是结构生物学家，协助蛋白功能的研究尤为重要。其他技术，如质谱法或 SDS-PAGE，只能提供信息的一维结构的蛋白质。蛋白质结晶被辅的重组蛋白的表达和 x 射线衍射技术。本视频将显示在生化领域的蛋白质结晶，一般实验室程序，和几个及其应用原则。
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在过程中所需的第一步是蛋白的获得毫克量的很纯，通常使用重组蛋白的表达。对应于感兴趣的蛋白质的基因表达载体，克隆并表达的蛋白融合到亲和标记，例如聚-组氨酸，协助亲和层析纯化。要了解更多信息，见此集合的视频上亲和层析。
纯化蛋白形成晶体是依赖于许多因素，包括 ph 值、 离子强度、 沉淀剂浓度和蛋白质、 温度和速率平衡的适当结合。使用的最常见方法是蒸气扩散，其中有两种类别: 挂滴和坐在下降。液滴含纯蛋白、 缓冲区和沉淀剂、 离子固体，束缚水分子，减少蛋白质的水供应和模仿蛋白质浓度越高，处于封闭微孔与储层更高浓度的相同的缓冲区和沉淀剂混合物。在开始时，蛋白质和沉淀剂的浓度是太低，不足以引起结晶。在实验过程中，水从液滴蒸发和收集在储层中;水在滴减少会导致系统变得饱和，和成核，其次是结晶，可以发生。水从液滴的净转移处于平衡状态，和系统维护过程完成之前。
若要可视化的三维结构，使用了 x 射线衍射。要获得晶体的 x 射线数据，它被放在单色 x 射线，在那里它被暴露在各个角度梁。每次曝光提供的图像，在每个地方是衍射 x 射线，从晶体产生、 由探测器注册。数据相结合，制作一个模型在晶体内部原子的排列。由此产生的晶体结构演示原子，典型分辨率为 2 埃的 3 维位置。
既然我们已经涵盖了蛋白质结晶的原则，让我们看看一个广义的协议。
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开始执行程序将包含感兴趣的基因表达载体转化为细胞。孵育细胞和阶段中期日志，表达式由添加诱导剂，如 IPTG，触发基因的 mRNA 转录启动。后蛋白表达，原油材料悬浮在裂解缓冲液中，然后用离心法澄清。
阐明了裂解液然后装到镍列和应运而生标记蛋白将绑定到列，而所有其他生物分子都冲走了。
一旦获得了几毫克的纯蛋白质，它是准备由蒸气扩散的结晶。24 井挂/坐滴托盘充满不同浓度的氯化钠和钠醋酸缓冲溶液。坐滴方法，相同体积的蛋白质和储层的解决方案吸取到每口井，上方的架子上，然后托盘布满了透明胶带。托盘然后放在孵化室，并在井监视增长第二天，然后每隔几天。
一旦它获得了适当的水晶是准备 x 射线衍射分析。水晶被安装在测角仪定位在所选的方向位置的晶体。水晶被照明用的 x 射线在所有的角度，产生衍射图案单色光束。该软件将转换的二维图像，在不同的方向，对三维模型的测定原子在晶体中的位置晶体中的电子密度。
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我们已经讨论了一种程序，让我们回顾一些有用的应用程序的蛋白质结晶和另一种结晶技术。
可用于蛋白质结晶硅药物设计中。流感病毒聚合酶碱性蛋白 2，其中已链接到病毒感染在哺乳动物中，三维结构测定结晶和 x 射线衍射。潜在的蛋白结合位点的可视化，并使用对接程序，设计了一个三维分子，会插入在蛋白质中的裂缝。
合作的结晶的蛋白质-DNA 复合物也是一个有用的技术。DNA 结合蛋白调节种类繁多的生物功能，如转录和 DNA 聚合和 DNA 修复;和这些配合物的晶体结构可以洞察蛋白质的功能、 机制及特异性相互作用的性质。大肠杆菌蛋白 SeqA，负性调节因子的 DNA 复制，是与半甲基化 DNA 位共同结晶。
一体式膜蛋白质如 G 蛋白偶联受体或 GCPRs，很难结晶由于其数量有限的极性表面积供形成晶体的晶格接触，导致融合蛋白辅助蛋白质结晶的发展。编码 β 2 肾上腺素能受体、 GCPR 和溶菌酶基因被插入表达载体。Β2AR 溶菌酶融合蛋白质结晶过程被达到由于增加胞外亲水表面自然疏水 β2AR，提供的溶菌酶，成型包装的相互作用在晶体点阵的必要条件。
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你刚看了朱庇特的视频对蛋白质结晶。这段视频描述其原则、 广义的议定书 》，和一些及其在生物医学领域的应用。谢谢观赏 ！
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蛋白质结晶，即获得生物大分子的固态晶格，有助于阐明蛋白质结构，并推动对蛋白质功能的研究。

蛋白质结晶是指获得蛋白质晶格状固体形式的过程。这些晶体对结构生物学家尤为重要，有助于研究蛋白质的功能。其他技术（如质谱或SDS-PAGE）只能提供有关蛋白质一维结构的信息。蛋白质结晶通常与重组蛋白表达和X射线衍射技术相结合使用。本视频将介绍蛋白质结晶的基本原理、通用的实验操作流程，以及其在生物化学领域中的若干应用。该流程所需的首要步骤是获得毫克量级的高纯度蛋白质，通常通过重组蛋白表达来实现。将目标蛋白对应的基因克隆至表达载体中，并使表达的蛋白与亲和标签（如多组氨酸标签）融合，以利于通过亲和层析进行纯化。欲了解更多信息，请参见本合集中关于亲和层析的视频。纯化蛋白质形成晶体的过程依赖于多种因素的恰当组合，包括pH、离子强度、沉淀剂和蛋白质的浓度、温度以及平衡速率。最常用的方法是蒸气扩散法，该法又分为两类：悬滴法和坐滴法。将含有纯化蛋白质、缓冲液和沉淀剂的液滴置于微孔板中，其中沉淀剂为一种可结合水分子的离子固体，能降低水分子对蛋白质的可用性，从而模拟更高的蛋白质浓度；微孔板内还设有储液池，其中含有相同缓冲液和沉淀剂但浓度更高的混合液，整个系统处于密闭环境中。实验初期，液滴中蛋白质和沉淀剂的浓度尚不足以引发结晶。在实验过程中，液滴中的水逐渐蒸发并凝集于储液池中；随着液滴内水量减少，体系逐渐达到过饱和状态，从而可能发生成核并继而形成晶体。水从液滴中的净转移最终达到平衡状态，整个系统将维持此平衡直至过程完成。为了可视化三维结构，需使用X射线衍射技术。要从晶体获得X射线数据，需将晶体置于单色X射线束中，并使其在各个角度暴露于该射线束。每次曝光都会产生一幅图像，其中每个斑点代表从晶体中衍射出的X射线，并由探测器记录。这些数据被合并以生成晶体内部原子排列的模型。所得的晶体结构展示了原子的三维空间排布，通常分辨率为2埃。现在我们已经了解了蛋白质结晶的原理，接下来让我们来看一个通用的实验方案。开始实验时，将含有目的基因的表达载体转化至细胞中。细胞培养至对数生长中期后，通过加入诱导剂（如IPTG）启动基因表达，从而触发目的基因mRNA的转录。蛋白表达完成后，将粗提物悬浮于裂解缓冲液中，随后通过离心澄清。将澄清的裂解液上样至镍柱，带有聚组氨酸标签的蛋白会结合到柱子上，而其他所有生物分子则被洗去。当获得数毫克纯蛋白后，即可采用蒸气扩散法进行结晶。将不同浓度的氯化钠和醋酸钠缓冲溶液加入24孔悬滴/坐滴板中。对于坐滴法，用移液器将等体积的蛋白溶液和储液槽溶液滴加到每孔上方的平台表面，然后用透明胶带密封整块板。将该板置于培养箱中，次日开始观察各孔中晶体生长情况，之后每隔数天观察一次。获得合适的晶体后，即可进行X射线衍射分析。将晶体安装在测角仪上，以将其固定在选定的取向。用单色X射线束从各个角度照射晶体，产生衍射图样。软件通过确定晶体中原子的位置，将不同取向下采集的二维图像转换为晶体内部电子密度的三维模型。现在我们已经回顾了一种实验方法，接下来让我们探讨蛋白质结晶的一些有用应用，以及另一种结晶技术。蛋白质结晶可用于计算机辅助药物设计。通过结晶和X射线衍射技术，已确定与哺乳动物病毒感染相关的流感病毒聚合酶碱性蛋白2（polymerase basic protein 2）的三维结构。该蛋白中的潜在结合位点得以可视化，并借助分子对接程序，设计出可插入该蛋白裂隙中的三维分子。蛋白质-DNA复合物的共结晶也是一种有用的实验技术。DNA结合蛋白能够调控多种生物学功能，例如转录、DNA聚合以及DNA修复；而这些复合物的晶体结构有助于深入了解蛋白质的功能、作用机制以及特异性相互作用的本质。大肠杆菌（E. coli）中的SeqA蛋白是一种DNA复制的负调控因子，已被与半甲基化DNA共结晶。诸如G蛋白偶联受体（GCPRs）之类的整合膜蛋白由于可用于形成晶体晶格接触的极性表面区域有限，难以结晶，这促使了融合蛋白辅助蛋白质结晶技术的发展。编码GCPR之一的β2肾上腺素受体（?2 adrenergic receptor）和溶菌酶的基因被插入表达载体中。由于溶菌酶提供了额外的胞外亲水表面，使得原本天然疏水的β2AR（?2AR）亲水性增加，从而实现了?2AR-溶菌酶融合蛋白的结晶，该亲水表面对于晶体晶格中堆积相互作用的形成至关重要。您刚刚观看了 JoVE 关于蛋白质结晶的视频。该视频介绍了其原理、通用实验方案以及在生物医学领域中的一些应用。感谢观看！

Education

教育

JoVE Science Education

Chemistry

化学

Biochemistry

生物化学

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 protein using recombinant expression. The gene of interest is placed in an expression vector, and the protein is given an affinity tag, such as a poly-histidine tag, so it can be purified by affinity chromatography. After purification, the protein is ready for crystal growth.

Crystal formation depends on several conditions. These include pH, ionic strength, protein concentration, precipitant concentration, temperature, and the rate of equilibration. The most common approach is vapor diffusion. In hanging drop and sitting drop setups, a droplet of protein, buffer, and precipitant sits in a sealed chamber with a reservoir that has a more concentrated solution. As water leaves the droplet and moves toward the reservoir, the drop becomes supersaturated. That change can lead to nucleation and then crystal growth.

Once a crystal forms, x-ray diffraction is used to study its 3D structure. The crystal is placed in a monochromatic x-ray beam and exposed from many angles. Each exposure creates a pattern of diffracted spots that a detector records. Software combines the data into a model of electron density and the atom positions in the crystal. The resulting structure can reach about 2 angstroms of resolution.

A general laboratory workflow includes transformation of the expression vector into cells, induction with IPTG during mid-log growth, lysis, centrifugation, and purification on a nickel column. After several milligrams of pure protein are collected, the sample is set up in a 24-well hanging or sitting drop tray. Different sodium chloride and sodium acetate buffer conditions are tested, and the wells are checked for crystal growth over time. When a suitable crystal appears, it is mounted on a goniometer and analyzed by x-ray diffraction.

Protein crystallization has several important uses. It supports in silico drug design by helping scientists see binding sites, as shown with influenza virus polymerase basic protein 2 and a designed docking molecule. It also helps study protein-DNA complexes, such as SeqA bound to hemimethylated DNA, which can reveal how proteins control transcription, DNA polymerization, and DNA repair. Membrane proteins like G-protein coupled receptors are harder to crystallize because they have limited polar surface area for crystal contacts. Fusion-protein-assisted crystallization can help, as seen with the beta2 adrenergic receptor fused to lysozyme.

Protein Crystals for Structure Analysis

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 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)

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...

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。

See how purified proteins form crystals, how vapor diffusion works, and how x-ray diffraction reveals 3D protein structure for biology and drug design.

Protein Crystals for Structure Analysis | 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 Protein Crystallization

Protocol for Protein Expression, Crystallization, and X-Ray Diffraction

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 ...

/files/media/science-education/science-education-thumbs/14721.jpg

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

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.

concept-of-resonance-and-its-characteristics

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 ...

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An Introduction to the Zebrafish: Danio rerio

Zebrafish (Danio rerio) are small freshwater fish that are used as model organisms for biomedical research. The many strengths of these fish include their ...

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.

Protein Crystals for Structure Analysis

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