- What do B cells do when activated?
- What property do thermoplastics have that make them desirable polymers?
- What causes cross linking?
- How does UV crosslinking work?
- What is a UV crosslinker used for?
- What is the major purpose of cross linking in polymers?
- Are cross linked polymers brittle?
- Why does PVA dissolve in water?
- What is the difference between linear and cross linked polymer?
- How does cross linking increase the strength of polymers?
- What happens during cross linking?
- What is a crosslinking agent?
- What is cross linking of proteins?
- What is cross linked collagen?
- What is cross linking of antibodies?
- Why is cross linking important?
- Why does adding acid break the cross linking?
- What is cross linked hyaluronic acid?
- Do thermoplastics have cross links?
- What does Borax do to PVA?
- How does cross linking affect polymer properties?
- What is UV crosslinking?
- Why are cross links required in rubber?
What do B cells do when activated?
B cell activation.
When naïve or memory B cells are activated by antigen (and helper T cells—not shown), they proliferate and differentiate into effector cells.
The effector cells produce and secrete antibodies with a unique antigen-binding (more…).
What property do thermoplastics have that make them desirable polymers?
Thermoplastics generally provide high-strength, flexibility and are resistant to shrinkage, depending on the type of resin (the polymer in melted liquid form). They are versatile materials that can be used for anything from plastic carrier bags to high-stress bearings and precision mechanical parts.
What causes cross linking?
Cross-links can be formed by chemical reactions that are initiated by heat, pressure, change in pH, or irradiation. For example, mixing of an unpolymerized or partially polymerized resin with specific chemicals called crosslinking reagents results in a chemical reaction that forms cross-links.
How does UV crosslinking work?
Crosslinking is generally achieved using ultraviolet (UV) light to induce the formation of a covalent bond between unmodified RNAs or between RNA and a photoaffinity reagent incorporated randomly or at specific positions in the RNA structure (Elad, 1976).
What is a UV crosslinker used for?
Immobilization of Nucleic Acids to Membranes The UVP Crosslinker is a microprocessor controlled UV irradiation system dedicated to nucleic acid linking to membranes for Southern, Northern, Dot and Slot Blot applications. It can also be used for UV disinfection and for elimination of PCR contaminations.
What is the major purpose of cross linking in polymers?
Cross-Linking Between Polymer Chains 4). Cross-linking by polymer reactions between linear polymers facilitates the formation of a homogeneous network structure and the control of degree of cross-linking.
Are cross linked polymers brittle?
These crosslinks tie all the polymer molecules together. … Also, because all the polymer molecules are tied together, they aren’t easily broken apart from each other. This is why Charles Goodyear’s vulcanized rubber doesn’t get brittle when it gets cold.
Why does PVA dissolve in water?
Since PVA is a temperature-stimuli polymer to dissolve it in the water you should use a heater to raise the water temperature to 90 oC and stir the mixture continuously.
What is the difference between linear and cross linked polymer?
The key difference between cross linked polymer and linear polymer is that the monomer units of linear polymers have end-to-end links, resembling the beads in a necklace, whereas cross linked polymers are made up of chains that are joined together by a series of covalent bonds, called cross-links.
How does cross linking increase the strength of polymers?
7.24 Explain how cross linking improves the strength of polymers. o Crossed linked polymers contain additional bonds between the molecules that provide resistance to flow. All of the extra links or bonds must be broken before the molecules can move relative to each other. … Some polymers are conductive naturally.
What happens during cross linking?
The procedure causes new corneal collagen cross-links to develop. Those cross links cause the collagen fibrils to shorten and thicken, leading to a stiffer, stronger cornea. Corneal cross linking is an outpatient procedure that typically lasts for about an hour.
What is a crosslinking agent?
Crosslinking reagents (or crosslinkers) are molecules that contain two or more reactive ends capable or chemically attaching to specific functional groups (primary amines, sulfhydryls, etc.) on proteins or other molecules.
What is cross linking of proteins?
Crosslinking is the process of chemically joining two or more molecules by a covalent bond. … Attachment between groups on two different proteins results in intermolecular crosslinks that stabilize a protein-protein interaction.
What is cross linked collagen?
The formation of collagen cross-links is attributable to the presence of two aldehyde-containing amino acids which react with other amino acids in collagen to generate difunctional, trifunctional, and tetrafunctional cross-links. … Once this condition is met, cross-linking occurs in a spontaneous, progressive fashion.
What is cross linking of antibodies?
Term. What is antibody cross-linking? Definition. When the two arms of an Ig bind different cells, changing it to a T-shape, allowing for precipitation and agglutination. Term.
Why is cross linking important?
Cross-link is a bond which links one polymer chain to other. … Cross linking increases the molecular mass of a polymer. Cross-linked polymers are important because they are mechanically strong and resistant to heat, wear and attack by solvents.
Why does adding acid break the cross linking?
Adding acid to the slime breaks the crosslinking producing a liquid with lower viscosity. Adding alkali reverses the process and the slime should be regenerated.
What is cross linked hyaluronic acid?
Cross-linking of the hyaluronic acid (hyaluronan, HA) molecule may be a possible chemical modification via which to improve the problem of the penetration of HA. … The hydration effect was kept and the rheological parameters were slightly changed after the cross-linking procedure.
Do thermoplastics have cross links?
Thermoplastics may be cross-linked using irradiation techniques and chemical agents. Their effect is to interconnect the long-chain molecules of the thermoplastic by covalent bonds, with the results being much the same as when thermoset resins are cured or hardened by curing agents.
What does Borax do to PVA?
In this experiment, a polymer (polyvinyl alcohol) chemically reacts with borax to form a crosslinked polymer network. Individual polymer chains are formed by covalent bonds, which are strong bonds. In making slime, the individual polymer chains are bound together by weak hydrogen bonds.
How does cross linking affect polymer properties?
Cross-linking Rubber and some other polymers can be cross-linked. A chemical reaction takes place that connects the chains to each other permanently. This makes the whole structure more rigid and less elastic. It also makes the material a lot stronger and harder.
What is UV crosslinking?
UV cross-linking assay is a standard method used to detect protein-RNA interaction. This method takes advantage of UV irradiation to trigger the formation of the covalently bonded RNP (ribonucleoprotein) complex that is more stable and makes it possible to be isolated in the denaturing conditions.
Why are cross links required in rubber?
To have practical applications why are cross links required in rubber? Solution: The cross links make the rubber hard, tough with greater tensile strength. The vulcanized rubber has excellent elasticity, low water absorption tendency, resistance to oxidation arid organic solvents.