Name: how maldi-tof reads biomolecules
Uploaded: 2023-04-30T06:31:26.000Z
Duration: 7 min 27 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.

MALDI-TOF Mass Spectrometry

maldi-tof 質量分析法

マトリックス支援レーザー脱離イオン化 (MALDI) は、生体分子の解析に最適な質量分析イオン源です。気体状の化合物をイオン化、代わりにサンプルはレーザーによって打たれるマトリックスに埋め込まれます。マトリックスは、エネルギーの大半を吸収します。このエネルギーの一部は、サンプルでは、結果としてイオン化するに転送されます。試料イオンは、飛行時間 (TOF) アナライザーを使用して識別できます。
このビデオは、行列と飛行時間型の質量電荷比を明らかにする使用方法を含む、MALDI-TOF の原則をカバーしています。この手順は、MALDI プレート、プレート、サンプルの読み込みと TOF 質量分析計の操作の準備を示しています。最後のセクションでは、アプリケーションおよびバリエーションが表示されます、全細胞分析を含む複雑な生体試料および電子スプレー イオン化の評価。
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マトリックス支援レーザー脱離イオン化または MALDI は、生体分子の解析に最適な質量分析計のイオン源であります。ほとんどのイオン源は、大規模な壊れやすい生体分子から構造情報を削除します。MALDI は、構造の整合性、およびしたがってについては、サイズと料金に基づいて化合物を分離する質量分析計に分子を加速中に保持されます。MALDI と最もよく結合は、フライト、または TOF 質量分析計の時間です。このビデオは、生化学の MALDI イオン化、一般的な手順とその利用方法のいくつかの概念が表示されます。
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関数に質量の気体の状態に分子をイオン化する必要があります。MALDI は、サンプル マトリックス、通常、有機化合物含有芳香族および共役二重結合で埋め込まれます。
レーザー パルスは、マトリックスを吸収するこの混合物を打つとき、エネルギーの大半急速に加熱、脱着、またはが、表面から放出されます。通電の行列は、放出とそれらを電離し、生体分子にそのエネルギーの一部を転送します。
MALDI 通常フライト、または TOF 質量分析計の時間とペアになっています。電界は、イオン、ドリフト管と呼ばれる無料のフィールドの領域にそれらを移動する運動エネルギーを適用します。イオンの速度管を通って移動するに関連する、質量電荷比重い粒子は通過計測器は遅いので。管の端に検出器は、各イオンの飛行時間を計測します。この知識と同様にチューブの長さと磁場強度、各イオンの質量電荷比を解明することができます。
大量に電荷比、信号強度のこのプロット質量スペクトルとして知られ、収集したスペクトルの図書館と比較できます。分子ことができる一致が見つからない場合タンデム質量分析法などのさらなる技術によって識別することができます。詳細については、トピックをこのコレクションのビデオを参照してください。
MALDI-TOF の基本が議論されている今、研究室では、プロセスを見てみましょう。
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実験を開始する前にサンプルの脱着ができるマトリックスの選択を検討することが重要です。それする必要がありますレーザー エネルギーを吸収する、真空中で安定である、ない標的分子と反応、脱着することができます。、サンプルの種類に応じて異なる行列が優先されます。大きい蛋白質 CHCA と DHB の組み合わせは個々 の行列よりも解像度と呼ばれるピークのよりよい分離を示しています。
いくつかのサンプルを準備する方法があります。「二重層」、または「サンドイッチ」方式と呼ばれるものを紹介します。まず、質量は汚染に非常に敏感、超高純度試薬、MALDI プレートをきれい。不活性ガスの流れとプレートを乾燥させます。
次に、飽和マトリックス ソリューションで作られています、通常有機溶剤。ソリューションは MALDI プレートに縞になる、乾燥します。トリフルオロ酢酸または、TFA を含む行列の 2 番目の飽和溶液を調製します。TFA の気体段階にイオンに役立ちます。
次に、サンプル ソリューションは、乾燥した行列スポットの上に追加されます。マトリックス「サンドイッチ」を完成、サンプル上に TFA を含むマトリックス ソリューションを追加します。スポットの均質性は、低倍率の顕微鏡下で確認できます。
知られている大衆の広い範囲との混合物であり m/z に飛行時間を関連付けるために使用は、校正標準をプレートします。最後に、陰性対照として単独での行列をプレートします。
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スポットを分析するには、楽器にターゲット プレートを配置します。破片、タイトな真空の形成を可能にするがないことを確認します。ソフトウェアで標準を選択、負の制御、および関心のサンプル。ラベルの正しい識別とスポット。
解析のパフォーマンスを改善するためにイオン源とレンズ電圧を操作できます。楽器やサンプルの仕様により異なります。標準のスポットに焦点を当てるし、ソフトウェアで計測器を校正します。
次に、各サンプル スポットからスペクトルを収集します。スポットで収集されたデータの品質を最大限にいくつかの異なる場所をみてください。終わったら、MALDI プレートを収集し、洗浄後再利用することができます。
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プロシージャを確認しましたところ、今は MALDI の活用方法と異なるイオン化技術のいくつかを見てみましょう。
生体分子に加え MALDI は生きた細胞を分析する使用できます。マクロファージは免疫細胞の微小環境に基づいて、いくつかの異なる形式のいずれかになります。様々 なシグナリング分子、またはサイトカイン細胞を公開した後に、板に直接追加および分析できます。MALDI のスペクトルは、一意な「指紋」を使用されるサイトカインによってとして使用できます。
哺乳類の皮脂分泌物のような複雑な生体試料 MALDI 解析の前に浄化のステップが必要です。薄層クロマトグラフィーは、部品の極性に依存しているようなの 1 つの手法です。化合物が TLC パテで採取、精製、MALDI のマトリックスに転送。結果として得られるスペクトルは、アイデンティティと哺乳類の皮脂分泌物から分離された生体分子の純度を確認します。
生体分子の別の一般的なイオン源は、エレクトロ スプレー イオン化または ESI です。このメソッドのサンプル、高電圧が適用される、楽器に注入帯電液滴の粒子を作成します。しぶきの溶剤が蒸発するまで、彼らは完全にガス料金はサンプルの分子に移行しました。ESI は、スポッティングの手順を必要としないし、サンプルは、楽器に直接注入することができます。その一方で、ESI は、MALDI はより堅牢な意味よりバッファー コンポーネントやその他の汚染物質の存在に敏感です。
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MALDI 質量分析法でゼウスのビデオを見てきただけ。このビデオは、計測器の背後にある理論を説明、一般的な手順行き、技術の用途のいくつかをカバーします。見てくれてありがとう!
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MALDI-TOF 質量分析法

Matrix-assisted laser desorption ionization (MALDI) is a mass spectrometry ion source ideal for the analysis of biomolecules. Instead of ionizing ...

マトリックス支援レーザー脱離イオン化法(MALDI)は、生体分子の分析に最適な質量分析イオン源です。ほとんどのイオン源は、大きくて壊れやすい生体分子から構造情報を除去します。MALDIは、分子を質量分析装置に加速し、サイズと電荷に基づいて化合物を分離しながら、構造的完全性、したがって情報を維持します。MALDIと最も一般的に組み合わされるのは、飛行時間(TOF)質量分析計です。このビデオでは、一般的な手順であるMALDIイオン化の概念と、生化学におけるその使用の一部を紹介します。質量分析が機能するためには、分子をイオン化して気体状態にする必要があります。MALDIでは、サンプルはマトリックス(通常は芳香族結合と共役二重結合を含む有機化合物)に埋め込まれます。レーザーパルスがこの混合物に当たると、マトリックスはエネルギーの大部分を吸収し、急速に加熱され、表面から脱着または放出されます。通電したマトリックスは、そのエネルギーの一部を生体分子に伝達し、それらを脱着させてからイオン化します。MALDIは通常、飛行時間(TOF)質量分析計とペアになります。電場はイオンに運動エネルギーを印加し、イオンをドリフトチューブと呼ばれる磁場のない領域に移動します。イオンがチューブ内を移動する際の速度は、質量電荷比に関係しているため、重い粒子は装置内をゆっくりと移動します。チューブの端にある検出器は、各イオンの飛行時間を測定します。この知識に加えて、チューブの長さや印加電界強度などから、各イオンの質量電荷比を解明することができます。この質量電荷比に対する信号強度のプロットは、質量スペクトルと呼ばれ、収集されたスペクトルのライブラリと比較できます。一致するものが見つからない場合は、タンデム質量分析などのさらなる技術で分子を同定できます。詳細については、このトピックに関するこのコレクションのビデオを参照してください。さて、MALDI-TOFの基本についてお話ししたところで、研究室でのプロセスを見ていきましょう。実験を始める前に、サンプルを脱離するマトリックスの選択を検討することが重要です。レーザーエネルギーを吸収し、真空中で安定し、標的分子と反応せず、脱着できる必要があります。サンプルに応じて、異なるマトリックスが好ましい。大きなタンパク質の場合、CHCA と DHB の組み合わせは、個々のマトリックスよりも分離度と呼ばれるピークの分離が良好であることを示しています。サンプルを調製するには、いくつかの方法があります。「ダブルレイヤー」または「サンドイッチ」メソッドとして知られているものを示します。まず、質量分析は汚染に非常に敏感であるため、MALDIプレートを超高純度試薬で洗浄します。プレートを不活性ガスの流れで乾かします。次に、飽和マトリックス溶液を、典型的には有機溶媒を用いて作製する。溶液をMALDIプレートに縞模様にし、乾燥させます。トリフルオロ酢酸(TFA)を含有するマトリックスの第2の飽和溶液を調製する。TFAは、イオンが気相に入るのを助けます。次に、乾燥したマトリックススポットの上にサンプル溶液を加えます。TFAを含むマトリックス溶液をサンプルの上に加えると、マトリックスの「サンドイッチ」が完成します。スポットの均一性は、低倍率の顕微鏡で確認することができます。プレートは、広範囲の既知の質量との混合物であり、飛行時間をm/zに関連付けるために使用されるキャリブレーション標準です。最後に、マトリックスのみをネガティブコントロールとしてプレートします。スポットを分析するには、ターゲットプレートを装置に入れます。破片が存在しないことを確認し、タイトな真空を形成できるようにします。ソフトウェアで、対象サンプル、ネガティブコントロール、サンプルを選択します。スポットに正しいIDのラベルを付けます。イオン源とレンズの電圧を操作して、分析のパフォーマンスを向上させることができます。これは、装置とサンプルの詳細によって異なります。標準スポットに焦点を合わせ、ソフトウェアで機器を校正します。次に、各サンプルスポットからスペクトルを収集します。収集したデータの品質を最大限に高めるために、その場でいくつかの異なる場所を試してみてください。完成したMALDIプレートは、洗浄後に回収して再利用することができます。手順を確認したので、MALDIの使用方法とさまざまなイオン化技術を見てみましょう。生体分子に加えて、MALDIは生細胞の分析にも使用できます。マクロファージは、その微小環境に基づいて、いくつかの異なる形態のいずれかをとる免疫細胞です。細胞をさまざまなシグナル伝達分子またはサイトカインにさらした後、それらをプレートに直接追加して分析することができます。MALDIスペクトルは、使用するサイトカインに応じて、固有の「フィンガープリント」として使用できます。哺乳類の皮脂分泌物のような複雑な生体サンプルは、MALDI分析の前に精製のステップが必要です。薄層クロマトグラフィーは、コンポーネントの極性に依存するそのような手法の1つです。化合物はTLCパテから収集され、精製され、MALDIマトリックスに移されます。得られたスペクトルは、哺乳類の皮脂分泌物から分離された生体分子の同一性と純度を確認します。生体分子のもう一つの一般的なイオン源は、エレクトロスプレーイオン化(ESI)です。この方法では、サンプルを装置に注入し、高電圧を印加して、帯電した液滴のエアロゾルを生成します。液滴中の溶媒が蒸発すると、電荷はサンプル分子に移動し、完全に気体になるまで移動します。ESIはスポッティング手順を必要とせず、サンプルを直接装置に注入できます。一方、ESIは緩衝成分やその他の汚染物質の存在に対してより敏感であるため、MALDIはより堅牢です。JoVEのMALDI質量分析に関するビデオをご覧になりました。このビデオでは、この機器の背後にある理論を説明し、一般的な手順を説明し、この技術の使用の一部について説明しました。ご覧いただきありがとうございます!

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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 energy. The matrix heats up, is desorbed from the surface, and transfers energy to the biomolecules so they ionize. MALDI is commonly paired with TOF, or time of flight, mass analysis.

The TOF analyzer uses an electric field to give ions kinetic energy and send them through a field-free drift tube. Ions move at different speeds based on their mass-to-charge ratio, so heavier ions travel more slowly. A detector measures each ion’s flight time. The instrument uses the tube length and field strength to calculate the mass-to-charge ratio and create a mass spectrum.

Before analysis, the matrix must be chosen carefully. It must absorb laser energy, stay stable in a vacuum, avoid reacting with the target molecules, and still desorb well. Different samples work better with different matrices. For a large protein, a combination of CHCA and DHB can give better peak resolution than either matrix alone.

Sample preparation can use the double-layer, or sandwich, method. First, the MALDI plate is cleaned with ultra-pure reagents and dried with inert gas, because mass spectrometry is sensitive to contamination. A saturated matrix solution is spotted and dried, then a second matrix solution containing trifluoroacetic acid, or TFA, is added with the sample in between. TFA helps ions enter the gaseous phase. The spot can be checked under a low-powered microscope.

A calibration standard is also plated. This standard contains a wide range of known masses and is used to match flight time to m/z. A matrix-only spot serves as a negative control. After the plate is loaded into the instrument, the software is used to label the spots, calibrate with the standard, and collect spectra from the samples. The ion source and lens voltages can be adjusted to improve performance, and several spots on each sample can be measured to improve data quality. The MALDI plate can be cleaned and reused after the run.

MALDI is also useful for whole-cell analysis and complex biological samples. Macrophages, which are immune cells, can be exposed to different cytokines and then analyzed directly on the plate. Their MALDI spectra can act as fingerprints for each cytokine condition. For mammalian sebaceous secretions, thin layer chromatography can first separate the components by polarity before the purified compounds are transferred to a MALDI matrix.

Another biomolecule ion source is electrospray ionization, or ESI. In ESI, the sample is injected directly into the instrument and a high voltage creates charged droplets. As the solvent evaporates, the charge moves to the sample molecules until they become gaseous. ESI does not need the spotting step, but it is more sensitive to buffer components and other contaminants, so MALDI is often the more robust choice.

How MALDI-TOF Reads Biomolecules

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

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...

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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...

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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...

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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

このコレクションでは、親和性クロマトグラフィーなどの一般的に使用される精製方法や、MALDI-TOFなどの分析方法について紹介します。さらに、共同免疫沈降法や代謝標識法など、生体分子の相互作用や機能を評価する方法も紹介します。

Learn how MALDI-TOF mass spectrometry uses a laser, matrix, and time-of-flight analyzer to identify biomolecules, cells, and complex samples.

How MALDI-TOF Reads Biomolecules | JoVE K12

Life Science

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

Matter and Energy in Organisms and Ecosystems

HS-LS1-6.

Overview

Principles of MALDI-TOF Mass Spectrometry

Plate, Matrix, and Sample Preparation

Running the Mass Spectrometer

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.

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 ...

propagation-speed-of-electromagnetic-waves

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 ...

an-introduction-to-drosophila-melanogaster

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 ...

an-introduction-to-the-zebrafish-danio-rerio

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 ...

An Overview of Genetics and Disease

Many human diseases are associated with mutations or variations in genetic sequences. Some of these genetic variants are heritable, passed down from ...

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.

How MALDI-TOF Reads Biomolecules

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