Immobilization

Question 1

The restriction of enzyme mobility in a fixed space

Answer 1

Enzyme immobilization

Question 2

Immobilization of enzymes provides important advantages, such as enzyme _____ and ____ of enzyme recovery and purification processes, and may provide a better environment for enzyme activity.

Answer 2

reutilization, elimination

Question 3

usually improved, and effluent handling problems are minimized by immobilization.

Answer 3

Product purity

Question 4

physical enclosure of enzymes in a small space

Answer 4

Entrapment

Question 5

two major methods of entrapment

Answer 5

Matrix entrapment and membrane entrapment

Question 6

used for enzyme immobilization are usually polymeric materials such as Ca-alginate, agar, k-carrageenin, polyacrylamide, and collagen

Answer 6

Matrices

Question 7

some solid matrices such as activated carbon, ___, and ____ earth can be also used for this purpose.

Answer 7

porous ceramic ,diatomaceous

Question 8

can be a particle, a membrane, or a fiber

Answer 8

Matrix

Question 9

either extruded or a template is used to shape the particles from a liquid polymer-enzyme mixture.

Answer 9

Polymerized gel-containing enzyme

Question 10

___ and ____ attachment may be used in combination in some cases.

Answer 10

Entrapment, surface

Question 11

common materials used for membranes in enzyme entrapment

Answer 11

Nylon, cellulose, polysulfone, and polyacrylate

Question 12

used to retain high molecular weight compound

Answer 12

semipermeable membrane

Question 13

membrane can be polymeric or an enriched interfacial phase

Answer 13

microencapsulation

Question 14

involves forming microscopic hollow spheres that contain the enzyme solution, enclosed within a porous membrane

Answer 14

Microencapsulation

Question 15

can be minimized by reducing the molecular weight cutoff of membranes or the pore size of solid matrices

Answer 15

Enzyme leakage

Question 16

can be eliminated by reducing the particle size of matrices and/or capsules

Answer 16

Diffusional limitations

Question 17

usually less significant in microcapsules as compared to gel beads.

Answer 17

Diffusion barrier

Question 18

two major types of surface immobilization of enzymes

Answer 18

adsorption and covalent binding

Question 19

the attachment of enzymes on the surfaces of support particles by weak physical forces, such as van der Waals or dispersion forces.

Answer 19

Adsorption

Question 20

The active site of the adsorbed enzyme is usually ____, and nearly full activity is retained upon adsorption.

Answer 20

unaffected

Question 21

a common problem, especially in the presence of strong hydrodynamic forces, since binding forces are weak

Answer 21

Desorption of enzymes

Question 22

stabilized by cross-linking with glutaraldehyde. Glutaraldehyde treatment can denature some proteins.

Answer 22

Adsorption

Question 23

Support materials used for enzyme adsorption

Answer 23

Inorganic - alumina, silica, porous glass, ceramics, diatomaceous earth, clay, bentonite.
Organic - cellulose (CMC, DEAE-cellulose), starch, activated carbon, and ion exchange resins, such as Amberlite, Sephadex, and Dowex

Question 24

is the retention of enzymes on support surfaces

Answer 24

Covalent binding

Question 25

bind to support material via certain functional groups, such as amino, carboxyl, hydroxyl, and sulfhydryl groups.

Answer 25

Enzyme molecules

Question 26

flooding the enzyme solution with a competitive inhibitor prior to covalent binding.

Answer 26

Blocking the active site

Question 27

molecules with agents such as glutaraldehyde can help in enzyme immobilization

Answer 27

Cross-linking enzyme

Question 28

___ and ___ of an enzyme from an organism require disruption of cells, removal of cell debris and nucleic acids

Answer 28

Separation, purification

Question 29

varies depending on whether the enzyme is intracellular or extracellular

Answer 29

Process scheme

Question 30

can be regulated and fermentation conditions can be optimized for overproduction of the enzyme

Answer 30

Enzyme production

Question 31

produced by using overproducing strains of Bacillus, Aspergillus, Rhizopus, and Mucor

Answer 31

Proteases

Question 32

produced by Aspergillus niger; lactases are produced by yeast and Aspergillus

Answer 32

Pectinases

Question 33

produced by certain strains of yeast and fungi

Answer 33

Lipases

Question 34

produced by Flavobacterium arborescens or Bacillus coagulans

Answer 34

Glucose isomerase

Question 35

are commonly used methods to separate cells from the media after the cultivation step

Answer 35

Filtration or centrifugation

Question 36

may be released by increasing the permeability of cell membrane

Answer 36

Intracellular enzymes

Question 37

hydrolyze proteins into smaller peptide units and constitute a large and industrially important group of enzymes

Answer 37

Proteases

Question 38

Proteases constitute about __ of the total enzyme market

Answer 38

60%

Question 39

Most of the industrial proteases

Answer 39

Endo proteases

Question 40

are used in food processing (cheese making, baking, meat tenderization, brewing), in detergents for hydrolysis of protein stains, and in tanning and medical treatment for wounds

Answer 40

Proteases

Question 41

produced mainly by A. niger. used in fruit juice processing and wine making to increase juice yield, reduce viscosity, and clear the juice

Answer 41

Pectinase

Question 42

are used to hydrolyze oils for soap manufacture, in wastewater treatment, in the cheese and butter industry to impart flavor, and in lipase-containing detergents

Answer 42

Lipases

Question 43

used for the hydrolysis of starch and are produced by many different organisms including A. niger and B. subtilis

Answer 43

Amylases

Question 44

breaks a -1,4 glycosidic bonds randomly on the amylose chain and solubilizes amylose. And is known as the starch liquefying enzyme.

Answer 44

A-amylase

Question 45

hydrolyzes a -1,4 glycosidic bonds on the nonreducing ends of amylose and produces maltose residues. And is known as a saccharifying enzyme.

Answer 45

B-amylase

Question 46

hydrolyzed to glucose by beta-glucosidase

Answer 46

Cellulases

Question 47

used in cereal processing, alcohol fermentation from biomass, brewing, and waste treatment

Answer 47

Cellulases

Question 48

five-carbon sugar units and are produced by some molds, such as white rot fungi and A. niger

Answer 48

Hemicellulases

Question 49

used in the fermentation of cheese.

Answer 49

Lactases

Question 50

is used by the antibiotic industry to convert penicillin G to 6aminopenicillanic acid (6-APA), which is a precursor for semisynthetic penicillin derivatives.

Answer 50

Penicillin acylase

Question 51

low-calorie sweetener

Answer 51

NutraSweet

Question 52

coupled with Lphenylalanine to produce aspartame

Answer 52

Aspartate

Question 53

nearly 1.7 times sweeter than glucose and is used as a sweetener in softdrinks

Answer 53

Fructose

Question 54

commonly used in medicine for diagnosis, therapy, and treatment purposes

Answer 54

Enzymes

Question 55

can be used as an anti-inflammatory agent

Answer 55

Trypsin

Question 56

hydrolyzes the cell wall of gram-positive bacteria, is used as an antibacterial agent.

Answer 56

Lysozyme

Question 57

used as an anti-inflammatory agent

Answer 57

Streptokinase

Question 58

dissolving and preventing blood clots

Answer 58

Urokinase

Question 59

produced by E. coli

Answer 59

Asparaginase

Question 60

used for the determination of glucose levels in blood and urine

Answer 60

Glucose oxidase

Question 61

used to treat allergic reactions against penicillin.

Answer 61

Penicillinases

Question 62

used in the dissolution of blood clots

Answer 62

Tissue plasminogen activator (TPA) and streptokinase

Question 63

Bacillus subtilis, Aspergillus niger. Starch hydrolysis, glucose production

Answer 63

Amylase

Question 64

A. niger, Rhizopus niveus, Endomycopsis. Saccharification of starch, glucose production

Answer 64

Glucoamylase

Question 65

Animal Pancreas Meat tenderizer, beer haze removal

Answer 65

Trypsin

Question 66

Papaya Digestive aid, meat tenderizer, medical applications

Answer 66

Papain

Question 67

Animal stomach Digestive aid, meat tenderizer

Answer 67

Pepsin

Question 68

Calf stomach/recombinant E. coli Cheese manufacturing

Answer 68

Rennet

Question 69

Flavobacterium arborescens, Bacillus coagulans, Lactobacillus brevis. Isomerization of glucose to fructose

Answer 69

Glucose Isomerase

Question 70

B. subtilis Degradation of penicillin

Answer 70

Penicillinase

Question 71

A. niger Glucose > gluconic acid, dried-egg manufacture

Answer 71

Glucose Oxidase

Question 72

Fungal Biopulping of wood for paper manufacture

Answer 72

Lignases

Question 73

Rhizopus, pancreas Hydrolysis of lipids, flavoring and digestive aid

Answer 73

Lipases

Question 74

S. cerevisiae Hydrolysis of sucrose for further fermentation

Answer 74

Invertase

Question 75

A. oryzae, A. niger, A. flavus Clarification of fruit juices, hydrolysis of pectin

Answer 75

Pectinase

Question 76

Trichoderma viride Cellulose hydrolysis

Answer 76

Cellulase