Methods for Immobilising Enzymes 0.0 / 5 ? BiologyPractical applications of biologyA2/A-levelOCR Created by: dork-knight95Created on: 18-03-14 20:24 Adsorption: Enzyme molecules mixed with immobilising support. They bind to it due to a combination of hydrophobic interactions and ionic links. Adsorbing agents include: porous carbon, glass beads, clays and resins. Weak bonding forces can lead to leakage (detachment of enzyme molecules.) Attaching enzymes without denaturing and displaying the active site leads to high reaction rates. 1 of 4 Covalent Bonding: Enzyme molecules covalently bonded to support. Covalently linked enzymes are linked to an insoluble material using a crosslinking agent (gluteraldehyde or sepharose.) Does not immobilise large quantities of enzyme. Strong binding so leakage is small. Covalent bonding can denature actibe site. 2 of 4 Entrapment: Enzymes may be trapped in gel bead or cellulose fibre network. Trapped in natural state so active site will not be affected. Reduced reaction rates as substrate must pass through barrier to reach active site and form enzyme-substrate complex. Active site less easily available than adsorption or covalent bonding. 3 of 4 Membrane Separation: Enzymes and substrates may be separated by a partially permeable membrane. Enzymes are held on one side of membrane, substrate passed along opposite side. Enzyme molecules are too large to pass through membrane. Substrate molecules are small enough to pass through membrane. Product molecules are small enough to pass back through the membrane. 4 of 4
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