Name: dialysis for buffer exchange in biochemistry
Uploaded: 2023-04-30T06:30:58.000Z
Duration: 5 min 26 s
Channel: JoVE

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Physical Science

HS. Structure and Properties of Matter

HS-PS1-10.

Dialysis: Diffusion Based Separation

A diálise é uma técnica comum usada na bioquímica para separar moléculas baseadas na difusão. Neste procedimento, uma membrana semipermeável permite o movimento de certas moléculas com base no tamanho. Este método pode ser aplicado à remoção de tampão, conhecido como desselting, ou troca de moléculas tampão ou íons de uma solução proteica.
Este vídeo abrange os princípios da diálise, juntamente com um procedimento geral.  Várias aplicações da diálise são revisadas, incluindo a remoção de reagentes gradientes após a ultracentrifugação, a remoção do detergente após uma extração de proteína de membrana e a reconstituição de proteínas mudando o ambiente de solução.

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diálise: separação baseada em difusão

A diálise é uma técnica comum usada na bioquímica para separar moléculas baseadas na difusão. Neste procedimento, uma membrana semipermeável permite o movimento de certas moléculas com base no tamanho. Este método pode ser aplicado à remoção de tampão, conhecido como desselting, ou troca de moléculas tampão ou íons de uma solução proteica.
Este vídeo abrange os princípios da diálise, juntamente com um procedimento geral.  Várias aplicações da diálise são revisadas, incluindo a remoção de reagentes gradientes após a ultracentrifugação, a remoção do detergente após uma extração de proteína de membrana e a reconstituição de proteínas mudando o ambiente de solução.
<div class="chapter_text" id="script_0">
As amostras bioquímicas normalmente têm altas concentrações de buffer que podem interromper o processamento e análise a jusante. A diálise é uma técnica comum e barata usada para separar moléculas baseadas na difusão. O método utiliza uma membrana semi-permeável que permite o movimento de certos componentes, com base no tamanho. Este vídeo mostrará os conceitos de diálise, um procedimento geral e alguns de seus usos na bioquímica.
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<div class="chapter_text" id="script_1">
O aspecto mais importante da diálise é uma membrana semi-permeável, que tem poros que impõem um corte de peso molecular, permitindo que moléculas abaixo de um certo tamanho passem. Por exemplo, uma membrana de 10k geralmente retém moléculas maiores que 10 kilodaltons. No entanto, o corte de peso molecular não é um limite discreto ou preciso. A membrana normalmente contém uma ampla gama de tamanhos de poros, de modo que uma pequena fração de moléculas perto do limite pode ser perdida.
Uma vez que o corte de peso molecular é definido usando proteínas globulares, moléculas lineares de massa semelhante, como DNA ou RNA, podem escapar. As membranas são tipicamente escolhidas de meio a um terço do peso molecular da molécula desejada.
Para realizar o procedimento, uma amostra é colocada na membrana, que por sua vez é adicionada a um grande volume de solução, chamado dialise. Com o tempo, moléculas menores se difundirão livremente através da membrana entre a amostra e o dialise, enquanto as biomoléculas maiores são mantidas dentro. Diálise é um processo lento. É comum permitir que ele seja executado durante a noite, ou mesmo em vários dias.
Se o dialise é água pura, a concentração total de tampão diminuirá, um processo conhecido como dessaciação. Se a solução contiver outras partículas pequenas, algumas se moverão para a amostra, levando à troca de buffer. Como a diálise é um processo de equilíbrio, o diálise pode ser atualizado várias vezes para deslocar ainda mais pequenas moléculas. Uma vez concluído o processo, a amostra é recolhia para posterior processamento.
Agora que você já viu o básico da diálise, vamos dar uma olhada em um procedimento geral.
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<div class="chapter_text" id="script_2">
Antes de iniciar o procedimento, a membrana é pré-diálise. Isso facilita o uso e remove quaisquer conservantes. Uma vez pronta, a amostra é coletada, tipicamente com uma seringa e, em seguida, adicionada ao recipiente de diálise. Isso pode ser tubos nus, ou contidos dentro de uma fita. O excesso de ar é removido da configuração da diálise para maximizar a área de superfície da amostra com a membrana. A configuração é então colocada no dialise com agitação para maximizar a difusão. Deve flutuar para não inibir a agitação.
O dialise é alterado em intervalos relevantes à medida que o equilíbrio entre a amostra e o dialise é atingido. Após a última mudança, a reação é normalmente deixada para funcionar durante a noite. Após um período de tempo suficiente, a amostra sem buffer ou trocada é removida do. Uma vez coletada, a amostra pode ser analisada ou processada posteriormente, dependendo da natureza do experimento.
</div>
<div class="chapter_text" id="script_3">
Agora que olhamos para um procedimento geral de diálise, vamos ver algumas das maneiras que esta técnica é usada na bioquímica.
Gradientes de densidade são uma maneira comum de separar amostras biológicas complexas. Este conceito se baseia na distribuição de pequenas partículas, tipicamente íons de sacarose ou cloreto de césio. Uma vez concluídos, esses reagentes normalmente precisam ser removidos antes que a amostra coletada possa ser processada. A diálise permite utilizar a amostra purificada para análise futura.
Certas proteínas são encontradas dentro da bicamada lipídica de uma célula, e geralmente são estudadas intercalando-as em vesículas lipídicas esféricas conhecidas como lipossomos. As proteínas e lipídios são extraídos pela primeira vez com um detergente. A diálise pode ser usada para remover lentamente o detergente, formando proteoliposomes.
Após a purificação, algumas proteínas são desdobradas, ou desnaturadas, levando a uma perda de funcionalidade. Os compostos que causam essas mudanças na estrutura podem ser removidos com diálise, levando à reforma dos analitos funcionais.
</div>
<div class="chapter_text" id="script_4">
Você acabou de ver o vídeo do JoVE em diálise. Agora você deve entender este método baseado em difusão, um procedimento experimental simples e o uso desta técnica.
Obrigado por assistir!
</div>

Diálise: Separação baseada em difusão

Dialysis is a common technique used in biochemistry for separating molecules based on diffusion. In this procedure, a semipermeable membrane allows the ...

As amostras bioquímicas normalmente têm altas concentrações de tampão que podem interromper o processamento e a análise a jusante. A diálise é uma técnica comum e barata usada para separar moléculas com base na difusão. O método utiliza uma membrana semipermeável que permite a movimentação de determinados componentes, com base no tamanho. Este vídeo mostrará os conceitos de diálise, um procedimento geral, e alguns de seus usos em bioquímica. O aspecto mais importante da diálise é uma membrana semipermeável, que possui poros que impõem um corte de peso molecular, permitindo a passagem de moléculas abaixo de um determinado tamanho. Por exemplo, uma membrana de 10k geralmente retém moléculas maiores que 10 kilodaltons. No entanto, o limite de peso molecular não é um limite discreto ou preciso. A membrana normalmente contém uma ampla gama de tamanhos de poros, portanto, uma pequena fração de moléculas perto do corte pode ser perdida. Como o limite de peso molecular é definido usando proteínas globulares, moléculas lineares de massa semelhante, como DNA ou RNA, podem escapar. As membranas são normalmente escolhidas de metade a um terço do peso molecular da molécula desejada. Para realizar o procedimento, uma amostra é colocada na membrana, que por sua vez é adicionada a um grande volume de solução, chamado dialisato. Com o tempo, moléculas menores se difundirão livremente através da membrana entre a amostra e o dialisato, enquanto as biomoléculas maiores são mantidas dentro. A diálise é um processo lento. É comum permitir que ele funcione durante a noite ou mesmo por vários dias. Se o dialisado for água pura, a concentração geral do tampão diminuirá, um processo conhecido como dessalinização. Se a solução contiver outras partículas pequenas, algumas se moverão para a amostra, levando à troca de tampão. Como a diálise é um processo de equilíbrio, o dialisato pode ser atualizado várias vezes para deslocar ainda mais pequenas moléculas. Uma vez concluído o processo, a amostra é coletada novamente para processamento posterior. Agora que você viu os fundamentos da diálise, vamos dar uma olhada em um procedimento geral. Antes de iniciar o procedimento, a membrana é pré-embebida em dialisato. Isso facilita o uso e remove quaisquer conservantes. Uma vez pronta, a amostra é coletada, normalmente com uma seringa e depois adicionada ao recipiente de diálise. Isso pode ser um tubo nu ou contido em um cassete. O excesso de ar é removido da configuração de diálise para maximizar a área de superfície da amostra com a membrana. A configuração é então colocada no dialisato com agitação para maximizar a difusão. Deve flutuar para não inibir a agitação. O dialisato é alterado em intervalos relevantes à medida que o equilíbrio entre a amostra e o dialisato é alcançado. Após a última alteração, a reação normalmente é deixada para ser executada durante a noite. Após um período de tempo suficiente, a amostra sem tampão ou trocada é removida do cassete. Uma vez coletada, a amostra pode ser analisada ou processada posteriormente, dependendo da natureza do experimento. Agora que analisamos um procedimento geral de diálise, vamos ver algumas das maneiras pelas quais essa técnica é usada em bioquímica. Os gradientes de densidade são uma maneira comum de separar amostras biológicas complexas. Este conceito baseia-se na distribuição de pequenas partículas, normalmente íons sacarose ou cloreto de césio. Depois de concluídos, esses reagentes normalmente precisam ser removidos antes que a amostra coletada possa ser processada. A diálise possibilita a utilização da amostra purificada para análises futuras. Certas proteínas são encontradas dentro da bicamada lipídica de uma célula e geralmente são estudadas intercalando-as em vesículas lipídicas esféricas conhecidas como lipossomas. As proteínas e lipídios são primeiro extraídos com um detergente. A diálise pode ser usada para remover lentamente o detergente, formando proteolipossomas. Após a purificação, algumas proteínas são dobradas incorretamente ou desnaturadas, levando a uma perda de funcionalidade. Os compostos que causam essas alterações na estrutura podem ser removidos com diálise, levando à reforma dos analitos funcionais. Você acabou de assistir ao vídeo da JoVE sobre diálise. Agora você deve entender esse método baseado em difusão, um procedimento experimental simples e o uso dessa técnica. Obrigado por assistir!

Education

JoVE Science Education

Chemistry

Química

Biochemistry

Bioquímica

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. Molecules near the cutoff can be lost, and linear molecules such as DNA or RNA may pass through more easily than globular proteins of the same mass. For that reason, membranes are often chosen at about one-half to one-third of the size of the molecule being kept.

To run dialysis, the sample is placed inside the membrane and then put into a large volume of solution called the dialysate. Over time, small molecules move across the membrane between the sample and the dialysate, while larger biomolecules stay in place. The process is slow, so it often runs overnight or even for several days. If the dialysate is pure water, the buffer level in the sample drops. This is called desalting. If the dialysate contains other small molecules, they can move into the sample, which creates buffer exchange. Because dialysis reaches equilibrium, the dialysate may be replaced several times to remove more small molecules.

A general dialysis procedure starts by presoaking the membrane in dialysate. This helps make the membrane easier to use and removes preservatives. The sample is then loaded with a syringe into tubing or a cassette. Excess air is removed to increase contact between the sample and the membrane. The setup is placed in dialysate with stirring so diffusion can continue efficiently. It should float so it does not block stirring. After the last dialysate change, the sample is usually left overnight and then collected for later analysis or further processing.

Dialysis is also useful in several biochemistry workflows. After density gradient separation, it can remove gradient reagents such as sucrose or cesium chloride ions before the sample is processed. It is also used after membrane protein extraction, where detergents are slowly removed to help form proteoliposomes from proteins and lipids. In another application, dialysis can remove compounds that caused proteins to misfold or denature, allowing the proteins to regain function in a new solution environment.

Dialysis for Buffer Exchange in Biochemistry

dialysis-for-buffer-exchange-in-biochemistry

dialysis: diffusion based separation

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

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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

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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

Esta coleção apresenta métodos de purificação comumente usados, como cromatografia de afinidade, bem como métodos analíticos, como MALDI-TOF. Além disso, os vídeos mostram métodos para avaliar a interação e função de biomoléculas, como coimunoprecipitação e marcação metabólica.

Learn how dialysis uses a semipermeable membrane to remove small molecules, exchange buffers, and support biochemistry workflows like desalting and protein recovery.

Dialysis for Buffer Exchange in Biochemistry | JoVE K12

Life Science

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

Matter and Energy in Organisms and Ecosystems

HS-LS1-6.

Overview

Principles of Dialysis

Dialysis Procedure

Applications

Summary

Periodic Classification of the Elements

The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their ...

atomic-radii-and-effective-nuclear-charge

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number ...

Ionic Radii

Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it ...

Ionization Energy

The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy ...

Electron Affinity

The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).



This process can be either ...

Electron Orbital Model

Orbitals are the areas outside of the atomic nucleus where electrons are most likely to reside. They are characterized by different energy levels, shapes, ...

The Aufbau Principle and Hund's Rule

To determine the electron configuration for any particular atom, we can build the structures in the order of atomic numbers. Beginning with hydrogen, and ...

Coordination Chemistry Complexes

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
Transition metals are found everywhere from vitamin ...

Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

HS-PS1-1.

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert&#xA0;N. Lewis. He developed a model called the Lewis model to explain the type and ...

Lewis Symbols and the Octet Rule

Chemical bonds are complex interactions between two or more atoms or ions, which reduce the potential energy of the molecule. Gilbert N. Lewis developed a ...

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence ...

The Born-Haber Cycle

Lattice Energy&#xA0;

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a ...

trends-in-lattice-energy-ion-size-and-charge

Trends in Lattice Energy: Ion Size and Charge

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure ...

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual ...

Electronegativity

Whether a bond is nonpolar or polar covalent is determined by a property of the bonding atoms called electronegativity.&#xA0;

Electronegativity values of ...

bond-polarity-dipole-moment-and-percent-ionic-character

Bond Polarity, Dipole Moment, and Percent Ionic Character

Bond Polarity

The absolute value of the difference in electronegativity (&Delta;EN) of two bonded atoms provides a rough measure of the polarity to be ...

lewis-structures-of-molecular-compounds-and-polyatomic-ions

Lewis Structures of Molecular Compounds and Polyatomic Ions

To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:


	Determine the ...

Resonance

The Lewis structure of a nitrite anion (NO2&minus;) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O ...

Formal Charges

In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to ...

Exceptions to the Octet Rule

Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:


	...

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Dr&#xFC;de called the ...

VSEPR Theory and the Basic Shapes

Overview of VSEPR Theory

Valence shell electron-pair repulsion theory (VSEPR theory) enables us to predict the molecular structure, including approximate ...

vsepr-theory-and-the-effect-of-lone-pairs

VSEPR Theory and the Effect of Lone Pairs

Effect of Lone Pairs of Electrons&nbsp;on Molecule Geometry

It is important to note that electron-pair geometry around a central atom is not the same ...

Predicting Molecular Geometry

VSEPR Theory for Determination of Electron Pair Geometries

The following procedure uses VSEPR theory to determine the electron pair geometries and the ...

Molecular Shape and Polarity

Dipole Moment of a Molecule

Polar covalent bonds connect two atoms with differing electronegativities, leaving one atom with a partial positive charge ...

Valence Bond Theory

Overview of Valence Bond Theory

Valence bond theory describes a covalent bond as the overlap of half-filled atomic orbitals (each containing a single ...

Hybridization of Atomic Orbitals I

The mathematical expression known as the wave function, &#x3C8;, contains information about each orbital and the wavelike properties of electrons in an ...

Hybridization of Atomic Orbitals II

sp3d and sp3d&nbsp;2 Hybridization

To describe the five bonding orbitals in a trigonal bipyramidal arrangement, we must use five of the valence shell ...

Molecular Orbital Theory I

Overview of Molecular Orbital Theory

Molecular orbital theory describes the distribution of electrons in molecules in the same way as the distribution of ...

Molecular Orbital Theory II

Molecular Orbital Energy Diagrams

The relative energy levels of atomic and molecular orbitals are typically shown in a molecular orbital diagram. For a ...

Molecular Orbital (MO) Theory

Source: Tamara M. Powers, Department of Chemistry, Texas A&#38;M University
This protocol serves as a guide in the synthesis of two metal complexes ...

Intermolecular vs Intramolecular Forces

Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular ...

Intermolecular Forces

Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions ...

Molecular and Ionic 
Solids

Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their ...

comparing-intermolecular-forces-melting-point-boiling-point

Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility

Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, ...

Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between particles.

HS-PS1-3.

Radioactivity and Nuclear Equations

Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for ...

Types of Radioactivity

The most common types of radioactivity are &#945; decay, &#946; decay, &#947; decay, neutron emission, and electron capture.
Alpha (&#945;) decay is the ...

Nuclear Stability

Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10&#8722;15 meters, a nucleus is ...

Nuclear Binding Energy

The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect ...

Radioactive Decay and Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. ...

Nuclear Fission

Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger ...

Nuclear Power

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by ...

Nuclear Fusion

The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process ...

Nuclear Transmutation

Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with ...

Biological Effects of Radiation

All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break ...

determining-rate-laws-and-the-order-of-reaction

Determining Rate Laws and the Order of Reaction

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
All chemical reactions have a specific rate defining the ...

Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.

HS-PS1-8.

Properties of Transition Metals

Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3&#8211;12 are ...

Coordination Compounds and Nomenclature

In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For ...

Metal-Ligand Bonds

The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain ...

Coordination Number and Geometry

For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to ...

physical-properties-of-minerals-i-crystals-and-cleavage

Physical Properties Of Minerals I: Crystals and Cleavage

Source: Laboratory of Alan Lester - University of Colorado Boulder
The physical properties of minerals comprise various measurable and discernible ...

Communicate scientific and technical information about why the particulate-level structure is important in the functioning of designed materials.

HS-PS2-6.

Dialysis for Buffer Exchange in Biochemistry

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