Name: measuring protein concentration with absorbance
Uploaded: 2023-04-30T06:31:14.000Z
Duration: 8 min 49 s
Channel: JoVE

K12 Standards

Next Generation Science Standards

High School

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Waves and Their Applications in Technologies for Information Transfer

HS-PS4-4

Photometric Protein Determination

光度法蛋白的测定

测量浓度是许多生化检测方法的基本步骤。光度法蛋白质测定利用这一事实，越样品含有吸光物质，少光将传送通过它。由于浓度与吸收之间的关系是线性的这种现象可以用于测量样品中的浓度在哪里是未知。
这个视频的光度蛋白测定基础知识，介绍了布拉德福德测定和洛瑞法。视频中的过程将涵盖典型的布拉德福德测定。应用程序覆盖包括直接测量很小卷的核酸浓度和纯度进行了表征，耦合效率的一种仿生材料和另一种变异的光度蛋白测定使用雷染料的测定。
<div class="chapter_text" id="script_0">
	样品中的蛋白质浓度测定的是在许多不同的生化分析的基本步骤。光度法测定可以用样本量太小。越多样本含有吸光物质，少光将传送通过它。这提供了吸收物质的定量测定。这些概念是如此根本的科学的文章，介绍的两种技术是在三个最常被引用文件中的所有时间。本视频将显示背后一些最常见的光度蛋白质的概念，测定技术、 执行的方式和如何对收集的数据进行分析。
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<div class="chapter_text" id="script_1">
	光度法蛋白测定基于浓度与光吸收能力之间的关系。这就是所谓的啤酒 — 朗伯定律，其中指出，吸光物质的浓度是成正比的吸光度。
	这一原则是所有光度蛋白质测定方法的基础。
	为直接吸收分析测量不变的蛋白样品的吸光度值。由于其芳香侧链，色氨酸和酪氨酸残基给高吸光度读数在波长为 280 nm。
	然而，这些氨基酸 — — 这是两个最不经常发现在蛋白质--都存在于不同数量在每个蛋白，所以每个测定是独特。为了克服这一局限性，更复杂的检测方法-那些不依赖于这些氨基酸-被开发了。
	一个例子是布拉德福德测定，彩色的染料对样品的添加位置。染料，考马斯亮蓝，被称为响应按比例更多蛋白质目前，更多的绑定事件与染料。
	然后，测定吸光度的绑定的考马斯亮蓝染料，吸收的光，594 测定蛋白质浓度毫微米。然而，布拉德福德测定是线性作短距离的浓度，因此稀释常被要求在分析之前。
	洛瑞法结合双缩脲试剂、 反应与肽键的铜离子和福林 Ciocâlteu 试剂，氧化芳香蛋白质残留的碱性溶液。由此产生的颜色变化是样品的蛋白质浓度成正比。
	吸收的减少福林试剂可以确定在 750 毫微米。像直接吸收，每种蛋白质有着独特的反应，和必须为感兴趣的蛋白质进行校准。既然我们已经回顾了一些最常见的化验背后的基本原则，让我们看看如何直接进行吸收和布拉德福德测定。
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<div class="chapter_text" id="script_2">
	若要开始直接吸收分析，分光光度计被校准与一片空白，零测定吸光度。标准的解决方案被编写用于创建校准曲线。分装的第一个标准是添加到试管中，然后放入分光光度计。
	吸光度值在 280 nm 然后记录。为每个标准，每次运行使用清洁试管重复此过程。一旦完成，校准曲线被创建通过绘制浓度与吸光度。这条线的斜率是摩尔的衰减系数，它涉及到浓度的吸光度。
	接下来，未知的样品添加到试管，并录得的吸光度值。随着不同的光度法测定方法的数据分析是相似的我们将介绍，之后我们看看布拉德福德测定。
	在这里，与牛血清白蛋白标准 96 孔板上进行布拉德福德蛋白测定。若要开始，BSA 股票解决方案做好准备。
	未知的解决方案被稀释用去离子水，以确保浓度检测的范围之内。根据试剂，考马斯亮染料可能还需要稀释。然后，校准曲线是由 96 孔板中加入牛血清白蛋白标准设置的。
	加去离子的水达到所需的浓度来生成标准曲线。未知的样品应添加到一式三份，确保采取准确的测量板。考马斯亮染料下一步添加到每个井，用吸管搅拌。
	去离子的水被添加到空井作为一片空白，测量吸光度。等待 5 分钟染料要绑定后, 吸光度测量板阅读器在 590 毫微米。
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<div class="chapter_text" id="script_3">
	现在，我们已经进行了几个检测方法，让我们看看如何来分析数据。每个光度蛋白质测定方法基于啤酒 — 朗伯定律。
	标准测量吸光度用于创建校准曲线，然后用来确定未知样品的浓度。这条曲线可以手动绘制，虽然新的分光光度法工具将创建校准曲线，一旦测量了所有的标准。这些系统还将计算蛋白质浓度未知的样品进行分析。
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<div class="chapter_text" id="script_4">
	既然我们已经讨论了如何分析光度法蛋白质测定数据，让我们看看一些利用这些程序的方法。
	光度法蛋白质测定的原则也可以用于直接测量核酸浓度。Nanodrop 分光光度计接受样品的光学活性的基座上体积很小。然后测定吸光度，和系统自动确定核酸浓度。因为蛋白质和其他来源可以干扰测量，样品纯度分析确定了 280 到 260 nm 和 260 到 230 nm 吸光度比值。纯核酸通常产生大约 1.8 和大约 2.0 的比率为 DNA 和 RNA，分别。
	光度法蛋白质测定也可以用于生产的仿生材料的灵感来自于自然，征求特定细胞的反应。重组的表面被绑定到聚苯乙烯珠子来模拟细菌吸附到宿主细胞。布拉德福德测定用于确定珠在仿生材料的生产重组粘附的耦合效率。
	替代的光度蛋白质检测可以用于检测和表征蛋白抗菌药物。雷亮蓝 R 染料是以共价键键合到热杀死细菌。抗菌蛋白是染色溶液中孵化的。然后，离心分离样品，和吸光的上清液在 595 nm 衡量使用酶标仪。增加的吸光度，释放到标记的细菌，培养上清的可溶性染料是酶活性的定量测定。
</div>
<div class="chapter_text" id="script_5">
	你刚看了光度蛋白质测定的朱庇特的视频。这个视频描述光度法测定的基本原则，走过去一些常见的检测方法，一般的程序，覆盖技术的一些新进展。谢谢观赏 ！
</div>

测量浓度是许多生物化学检测中的基本步骤。分光光度法蛋白质测定利用了以下原理：溶液中蛋白质浓度越高，...

测定样品中蛋白质的浓度是许多生物化学实验的基础步骤。分光光度法测定可用少量样品完成。样品中含有的吸光物质越多，透过的光就越少。这为吸光物质提供了定量测量的依据。这些概念在科学领域极为基础，其中介绍两种技术的论文位列有史以来被引用次数最多的三篇论文之中。本视频将介绍一些最常用的分光光度蛋白质测定技术背后的原理、实验操作方法以及所收集数据的分析方式。光度法蛋白质测定基于浓度与光吸收度之间的关系。这被称为比尔-朗伯定律，该定律指出，光吸收物质的浓度与其吸光度成正比。这一原理是所有光度法蛋白质测定方法的基础。对于直接吸收分析，需测定未修饰蛋白质样品的吸光度值。由于含有芳香族侧链，色氨酸和酪氨酸残基在280 nm波长处的吸光度值最高。然而，这两种氨基酸在蛋白质中含量最少，且在每种蛋白质中的含量各不相同，因此每次测定都是独特的。为了克服这一局限性，人们开发了更为复杂的检测方法，这些方法不依赖于这两种氨基酸。一个例子是 Bradford 法，即将有色染料加入样品中。这种被称为考马斯亮蓝的染料会产生相应的颜色反应——蛋白质含量越高，与染料发生的结合反应就越多。然后，通过测量结合的考马斯亮蓝染料在 594 nm 处的吸光度来确定蛋白质浓度。然而，Bradford 法的线性范围较窄，因此在分析前通常需要进行稀释。Lowry 法结合了双缩脲试剂（一种与肽键反应的铜离子碱性溶液）和福林-酚试剂（可氧化蛋白质中芳香族残基的试剂）。样品产生的颜色变化与蛋白质浓度成正比。可在 750 nm 处测定还原后的 Folin 试剂的吸光度。与直接吸收法类似，每种蛋白质均有其独特的响应，因此必须针对目标蛋白质进行校准。在回顾了若干最常用检测方法的基本原理之后，接下来让我们了解直接吸收法和 Bradford 法的具体操作步骤。开始进行直接吸收分析时，先用空白样品校准分光光度计，以确定零吸收值。制备标准溶液用于绘制校准曲线。然后，取第一份标准溶液的等分试样加入比色皿中，并放入分光光度计内。随后记录在 280 nm 处的吸光度值。对每个标准品重复此过程，每次运行均使用干净的比色皿。完成后，通过绘制吸光度与浓度的关系曲线来绘制标准曲线。该直线的斜率即为摩尔衰减系数，用于描述吸光度与浓度之间的关系。接下来，将未知样品加入比色皿中，并记录吸光度值。由于不同光度测定方法的数据分析过程相似，我们将在介绍完 Bradford 法之后统一进行说明。此处采用 BSA 标准品在 96 孔板上进行 Bradford 蛋白质测定。首先，配制 BSA 储备溶液。用去离子水稀释未知溶液，以确保其浓度处于检测方法的范围内。根据试剂盒的不同，考马斯亮蓝染料也可能需要稀释。然后通过将 BSA 标准品加入 96 孔板中建立标准曲线。加入去离子水以达到生成标准曲线所需的浓度。未知样品应以每组三个复孔的方式加入到孔板中，以确保获得准确的测量结果。随后将考马斯亮蓝染料加入各孔中，并用移液器混匀。向空孔中加入去离子水作为空白对照，用于测量吸光度。染料结合5分钟后，在酶标仪中于590 nm处测定吸光度。在完成若干项检测后，让我们来看如何分析数据。每种光度法蛋白质测定方法均基于朗伯-比尔定律。通过测定标准品的吸光度来绘制标准曲线，然后利用该曲线确定未知样品的浓度。该曲线可手动绘制，但较新的分光光度计在测定所有标准品后可自动生成标准曲线。这些系统在分析未知样品时还会自动计算蛋白质浓度。现在我们已经回顾了如何分析光度法蛋白质测定数据，接下来让我们探讨这些方法的一些实际应用方式。光度法蛋白质测定的原理也可用于直接测量核酸浓度。NanoDrop 分光光度计可在光学活性基座上接受极小体积的样品，然后测量其吸光度，系统会自动计算出核酸浓度。由于蛋白质及其他成分可能干扰测量结果，因此需通过分析 260 nm 与 280 nm 以及 260 nm 与 230 nm 的吸光度比值来判断样品纯度。纯的核酸样品，其 DNA 的比值通常约为 1.8，RNA 的比值通常约为 2.0。光度法蛋白质测定也可用于仿生材料的制备，这类材料受自然界启发，旨在引发特定的细胞反应。将重组黏附素结合到聚苯乙烯微球上，以模拟细菌对宿主细胞的黏附。在仿生材料制备过程中，采用Bradford法测定重组黏附素与微球的偶联效率。可采用替代性的光度法蛋白质检测方法来检测和表征具有抗菌活性的蛋白质。将雷马素亮蓝R染料共价结合到经加热灭活的细菌上，随后将抗菌蛋白样品与染色后的细菌溶液共同孵育。然后对样品进行离心，并使用微孔板分光光度计在595 nm处测定上清液的吸光度。上清液中可溶性染料的吸光度升高，反映了标记细菌释放的染料量，可作为酶活性的定量检测指标。您刚刚观看了 JoVE 关于光度法蛋白质测定的视频。该视频介绍了光度法测定的基本原理，概述了一些常用检测方法的常规操作步骤，并讲解了该领域中的一些新技术进展。感谢观看！

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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 and the Lowry method, which are two common ways to measure protein without relying only on direct absorption.

Direct absorption analysis measures the absorbance of an unaltered protein sample. At 280 nm, tryptophan and tyrosine give the strongest readings because of their aromatic side chains. However, these amino acids are present in different amounts in different proteins, so each sample has to be treated on its own.

The Bradford assay solves that limitation by adding Coomassie Blue dye to the sample. The dye binds to protein, and the more protein present, the more dye binds. The bound dye is read at 594 nm, but the assay is linear only over a short range, so samples often need dilution before analysis.

The Lowry method uses two reagents. The Biuret reagent contains alkaline copper ions that react with peptide bonds, and the Folin-Ciocalteu reagent oxidizes aromatic residues. The resulting color change is proportional to protein concentration, and the reduced Folin reagent is measured at 750 nm. Like direct absorption, the method must be calibrated for the protein being tested.

A direct absorption run starts by blanking the spectrophotometer to set zero absorbance. Standard solutions are then measured in clean cuvettes at 280 nm, and the absorbance values are plotted to make a calibration curve. The slope of that line is the molar attenuation coefficient, and the unknown sample is measured against the same curve.

The Bradford assay is often done on a 96-well plate using BSA standards. The unknown samples are diluted with deionized water so they fall within the assay range, and the standards are added to build a standard curve. The unknowns are usually added in triplicate, Coomassie dye is mixed into each well, a blank well contains deionized water, and the plate is read after 5 min at 590 nm.

Data analysis for these assays is based on the same Beer-Lambert relationship. The standard readings create a calibration curve that is used to find the concentration of unknown samples. Some newer spectrophotometric systems build this curve automatically and calculate protein concentration as samples are analyzed.

These ideas also apply to other measurements. Very small amounts of nucleic acids can be measured with a Nanodrop spectrophotometer, which reads absorbance on an optically active pedestal and estimates concentration automatically. Sample purity is checked with the 260/280 and 260/230 absorbance ratios, which are typically about 1.8 and 2.0 for pure DNA and RNA, respectively.

Photometric methods are also used in biomimetic materials, which are inspired by nature to trigger specific cellular responses. In one example, recombinant adhesins are attached to polystyrene beads to mimic bacterial binding to host cells, and the Bradford assay measures coupling efficiency. Another variation uses Remazol brilliant blue R dye on heat-killed bacteria to detect protein antimicrobials by measuring dye released into the supernatant at 595 nm after centrifugation.

Measuring Protein Concentration with Absorbance

measuring-protein-concentration-with-absorbance

dialysis: diffusion based separation

Dialysis for Buffer Exchange in Biochemistry

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Tandem Mass Spectrometry for Biomolecule Analysis

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Protein Purification with SEC and IMAC

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Protein Mapping with 2D Gel Electrophoresis

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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 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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Protein Interaction Capture Methods in Cells

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Membrane Proteins in Liposome Models

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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。

Learn how absorbance helps measure protein concentration with the Bradford assay, Lowry method, and direct absorption, plus related nucleic acid and biomaterial uses.

Measuring Protein Concentration with Absorbance | JoVE K12

HS-PS4-5

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Structure and Properties of Matter

HS-PS1-10.

HS. Waves and Electromagnetic Radiation

HS-PS4-4.

HS-PS4-5.

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 Photometric Protein Determination

Execution of Assays

Data 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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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 ...

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 ...

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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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. ...

Doppler Effect - I

The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments ...

Doppler Effect - II

The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on ...

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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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 ...

Generating Electromagnetic Radiations

The German physicist Heinrich Hertz (1857&#8211;1894) was the first to generate and detect certain types of electromagnetic waves in the laboratory. ...

Electromagnetic Wave Equation

Maxwell&#39;s equations for electromagnetic fields are related to source charges, either static or moving. These fields act on a test charge, whose ...

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 ...

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 ...

Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media. [Clarification Statement: Examples of data could include electromagnetic radiation traveling in a vacuum and glass, sound waves traveling through air and water, and seismic waves traveling through the earth.] [Assessment Boundary: Assessment is limited to algebraic relationships and describing those relationships qualitatively.]

HS-PS4-1

The Electromagnetic Spectrum

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

Classification of Signals

Signals are categorized as Continuous-time or discrete-time, Periodic or aperiodic, Analog or digital, and Causal or noncausal.
A continuous-time signal ...

Discrete Fourier Transform

Consider a vibration sensor that continuously captures data in the form of a continuous time-dependent signal.
However, in reality, the sensor can only ...

Discrete-Time Fourier Series

The Discrete-Time Fourier Series is a counterpart to the Fourier-series expansion of continuous-time periodic signals.
Calculating the expansion ...

Sampling Theorem

Consider the continuous-time signal x(t), and a train of impulses where Ts,&#xA0; is the sampling interval, and fs, is the sampling frequency.
Multiplying ...

Properties of Fourier Transform I

In radio broadcasting, Fourier Transform properties are applied in simultaneous multi-channel transmission, adjusting audio clip speeds, live broadcast ...

Signal and System

Signals are sets of data or information.
One-dimensional signals include single-variable functions, such as the variations in air pressure over time in ...

Methods of Documentation VII: EMR

Electronic Medical Records (EMRs) primarily center around electronically documenting patients&#39; health information within a single healthcare ...

Fast Fourier Transform

The Fast Fourier Transform, FFT, is a computational algorithm for calculating the Discrete Fourier Transform by breaking the calculations into smaller, ...

reconstruction-of-signal-using-interpolation

Reconstruction of Signal using Interpolation

Consider a continuous signal and its sampled counterpart with a sampling period T.
Applying a zero-order hold to the sampled signal results in a piecewise ...

Downsampling

Consider a sampled sequence with zero values between sampling instants. Replace it by taking every N-th value of the sampled sequence.
The original and ...

Design Example

An engineer designs a circuit for a speaker system with a 2 kHz crossover frequency requirement, considering the speaker&#39;s resistance of 8 ohms.
The ...

Upsampling

Consider a decimated signal with a reduced frequency range due to its lower sampling rate.
Insert zeros between each sample to upsample, that introduces ...

Properties of DTFT I

Consider two discrete-time signals, each with their respective Discrete-Time Fourier Transforms DTFTs.
The signals are first multiplied by constants a and ...

Relation of DFT to z-Transform

The Discrete Fourier Transform (DFT) analyzes the frequency content of discrete-time signals.
It maps the N-sampled discrete time-domain sequence to its ...

Feedback control systems

Feedback control systems are categorized as linear or nonlinear, time-varying or time-invariant, and classified by signal types as continuous or ...

Properties of the z-Transform I

Certain properties provide a solid foundation for analyzing discrete-time systems using the Z-transform.
Considering two discrete-time signals, the ...

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which ...

Evaluate questions about the advantages of using digital transmission and storage of information. [Clarification Statement: Examples of advantages could include that digital information is stable because it can be stored reliably in computer memory, transferred easily, and copied and shared rapidly. Disadvantages could include issues of easy deletion, security, and theft.]

HS-PS4-2

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 ...

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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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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Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other. [Clarification Statement: Emphasis is on how the experimental evidence supports the claim and how a theory is generally modified in light of new evidence. Examples of a phenomenon could include resonance, interference, diffraction, and photoelectric effect.] [Assessment Boundary: Assessment does not include using quantum theory.]

HS-PS4-3

Measuring Protein Concentration with Absorbance

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