Know About Electrophoresis- The Laboratory Quiz

Zone electrophoresis refers to the migration of charged molecules as distinct zones in a porous supporting medium, typically an agarose gel film, after the sample is mixed with a buffer solution. This technique allows for the separation and analysis of different components in a mixture based on their charge and size. By applying an electric field, the charged molecules move through the gel at different rates, resulting in the formation of distinct bands or zones. This method is commonly used in molecular biology and biochemistry for various applications, such as DNA sequencing and protein analysis.

The correct answer states that the rate of migration of biomolecules during electrophoresis is directly proportional to their net charge and inversely proportional to their molecular size and viscosity. This means that molecules with a higher net charge will migrate faster, while larger molecules and molecules in more viscous mediums will migrate slower. This is because molecules with a higher charge experience a greater force from the electric field, while larger molecules and molecules in more viscous mediums experience more resistance to movement.

Support media refers to the material or substance used in a separation process to facilitate the separation of components. In the context of the question, the support media is the matrix that provides the necessary environment for the separation to occur. It acts as a medium or platform on which the separation process takes place, allowing the components to interact and separate from each other. Therefore, the support media is the correct answer as it directly relates to the matrix in which the separation occurs.

In a more alkaline solution, the pH is higher, which means there are more hydroxide ions (OH-) present. The ampholyte molecule can act as both an acid and a base, and in this case, it acts as a base. In an alkaline solution, the ampholyte molecule will accept a proton (H+) from the solution, becoming negatively charged (negatively ionized). Since like charges repel, the negatively ionized ampholyte molecule will migrate toward the anode, which is the positively charged electrode. Therefore, the statement is true.

The correct answer is buffer. A buffer is a solution that resists changes in pH when small amounts of acid or base are added to it. In this context, a buffer carries the applied current and determines the electrical charge on the solute. It helps maintain a stable pH level in the solution by neutralizing any added acid or base. The buffer acts as a support medium for the solute, allowing it to carry the applied current and maintain its electrical charge.

A typical 7.5% polyacrylamide gel has an average pore size of about 5 nm (50 Å). This means that the gel has small openings or spaces between the polymer chains that make up the gel matrix, and these openings are about 5 nm in size. This information is true and accurately represents the average pore size in such a gel.

The isoelectric point (pI) of an ampholytes molecule refers to the pH at which the molecule becomes electrically neutral, meaning it has no electrical charge. At this pH, the molecule does not migrate within an electrical field because there are no charges to interact with the field.

Agarose gel is a substance used in molecular biology for various purposes such as DNA separation and protein analysis. It is a purified, uncharged polysaccharide that forms a gel-like matrix when dissolved in water. Agarose gel can be prepared by dissolving 0.5% agarose in boiling water and then allowing it to cool to 40°C. The gel matrix is formed by cross-linking agarose molecules, which helps to create a stable and uniform medium for electrophoresis. Therefore, all of the given statements are correct and describe different aspects of agarose gel.

The buffer's ionic strength influences the conductance of the support, which refers to the ability of the support to conduct electricity. A higher ionic strength can increase the conductance of the support, allowing for better movement of charged molecules during electrophoresis. The buffer's ionic strength also affects the thickness of the ionic cloud surrounding a charged molecule. A higher ionic strength can lead to a thicker ionic cloud, which can impact the rate of migration and the sharpness of the electrophoretic zones. Therefore, all of the given options are influenced by the buffer's ionic strength.

Electrophoretic mobility is influenced by various factors, including endosmotic flow and wick flow. Endosmotic flow refers to the movement of solvent molecules in the opposite direction of the electrophoretic migration, while wick flow refers to the movement of solvent through the gel or matrix. These additional flows can affect the overall mobility of the particles being analyzed during electrophoresis. Therefore, the statement that other actors, such as endosmotic flow and wick flow, affect electrophoretic mobility is true.

Iontophoresis is the correct answer because it refers to the migration of small ions. It is a technique that uses an electric current to transport ions through a solution. This process is commonly used in medicine and pharmacology to deliver drugs or other substances into the body through the skin. Electropherogram is not the correct answer because it refers to the graphical representation of electrophoresis results, while zone electrophoresis is a broader term that encompasses various techniques for separating and analyzing molecules based on their charge and size.

An ampholyte molecule is capable of both accepting and donating protons, which means it can act as both an acid and a base. In a solution that is more acidic than its isoelectric point (pI), the ampholyte molecule will be in its basic form and will have a positive charge. Therefore, it will migrate towards the anode (positive electrode) rather than the cathode (negative electrode). Therefore, the correct answer is false.

Agarose is the correct answer because it is a type of support media that is commonly used for the separation of various analytes such as serum, urine, or CSF proteins, hemoglobin variants, isoenzymes, and lipoproteins. Agarose is a polysaccharide derived from seaweed and has a porous gel-like structure that allows for the separation of different molecules based on their size and charge. It is widely used in techniques such as gel electrophoresis and gel filtration chromatography.

The electrophoresis apparatus consists of a power pack and an electrophoresis unit. The power pack provides the necessary electrical current for the process of electrophoresis, while the electrophoresis unit is where the gel and samples are placed for separation. The gel acts as a medium through which the samples can migrate based on their charge and size. Therefore, the correct answer is power pack and electrophoresis unit.

The speed of migration of ions in an electric field depends on the magnitude of charge and shape of the molecule. The magnitude of charge determines the strength of the electric field experienced by the ion, which affects its movement. The shape of the molecule also plays a role as it determines the resistance encountered by the ion as it moves through the medium. Therefore, both the magnitude of charge and shape of the molecule are important factors in determining the speed of ion migration in an electric field.

Starch gel is the first material used as a support medium to separate macromolecules based on their surface charge and molecular size. This means that starch gel can effectively separate macromolecules by considering both their charge and size.