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The correct option is (c) Adsorption

The best I can EXPLAIN: ATTACHMENT of enzymes to stationary SOLIDS by weak physical forces such as VANDER WAALS forces or dispersion forces. Active site is normally unaffected and nearly full activity is observed. Desorption of enzymes is a common problem.

The CORRECT choice is (d) Silica

The explanation is: NATURAL polymers are which will be polysaccharides are cellulose, dextran. Agar, agarose, chitin, alginate. Natural polymers of protein categories are collage, albumin. INORGANIC natural polymers are bentonite and silica. Inorganic PROCESSES materials are GLASS, metals, etc.

Right choice is (d) Pore parameters

For explanation I would say: Physical characteristics of the MATRICES such as MEAN particle diameter, swelling behaviour, MECHANICAL strength and COMPRESSION behaviour, etc. These physical characteristics are important for the performance of the immobilized conditions. Pore parameters and particle size determine the total surface area.

Right option is (c) Salt linkages

For explanation: The simplest immobilization method is nonspecific adsorption, based on physical adsorption or IONIC bonding for the drug MOLECULES with the polymeric molecules.The bonding between the drug and the polymer COMPOUND is REVERSIBLE. It also influences the strength of the INTERACTION.

Correct OPTION is (a) The entrapment method

To ELABORATE: In this method, the enzyme is not bound to the matrix or MEMBRANE. There are different approaches to entrapping ENZYMES such as gel or fibre entrapping and micro-encapsulation.

Right answer is (d) Cross-linking

To explain: The concept of IRREVERSIBLE immobilization MEANS that once the biocatalyst is ATTACHED to the support it cannot be detached without destroying either the biological activity of the enzyme or the support. Thus the most COMMON procedures of irreversible enzyme immobilization are covalent coupling, entrapment or micro-encapsulation and crosslinking of the enzyme with POLYMERS.

Correct option is (b) CHIBATA and co-workers

To elaborate: They have ALSO developed the immobilization of ASPERGILLUS oryzae aminoacylase for the resolution of synthetic racemic D-L amino acids. In their work fungal aminoacylase was immobilised on DEAE-Sephadex through IONIC bonding. They used this system to produce l-aspartate from ammonium fumarate.

The correct CHOICE is (a) Cross linking

To elaborate: Cross-linking is to cross link ENZYME molecules with each other USING AGENTS such as glutaraldehyde. Features are similar to covalent bonding. Several methods of crosslinking are COMBINED.

Correct option is (b) HOLLOW fibre configuration

Explanation: Hollow fibre configuration is a very popular arrangement for separating enzyme from SUBSTRATE and product can be taken out easily. Hollow fibres CONTAINING a stationery enzyme SOLUTION. Mobile fluid OUTSIDE fibres containing substrate and products.

Right CHOICE is (d) COLLAGEN

For explanation I would say: The matrices for ENTRAPMENT are Ca- alginate, AGAR, polyacrylamide, collagen. Membrane materials are enzyme solutions which will be confined between THIN semipermeable membranes. Membrane materials include nylon, cellulose, polysulfone, polyacrylate.

The CORRECT answer is (d) Solidifies into various forms

To explain: The ENZYME SOLUTIONS are mixed with a polymeric FLUID which will solidify the enzymes into various forms. The solidification depends on application. The polymeric material is semi-permeable. Large is the molecular weight enzymes cannot diffuse out, small SUBSTRATE and product molecules can.

Right option is (a) True

The explanation: The enzymes which were immobilized can be reused. Since the enzymes f=don’t GET wash off fully, and the active sites are preserved by staking the enzymes all together in a polyester gel. This has advantages of easier OPERATION, easier PRODUCT separation, and wider CHOICE of reactors.

Right CHOICE is (a) Nitrile Hydratase

The best EXPLANATION: Acrlamide is a monomer which is used for production of a lot of substances. It is produced by the addition of WATER to ACRYLAMIDE. The catalyst used in this process is nitrile hydratase. This catalyst is difficult to regenerate. Thus we have to use immobilised nitrile hydrates.

Correct option is (B) High fructose corn syrup

To explain I WOULD SAY: In corn syrup production the starch is broken down by enzymes. To make, high fructose corn syrup, the corn syrup has to be further broken down or processed by GLUCOSE isomerase. This step helps to CONVERT some of the glucose into fructose.

Correct choice is (d) Enzyme immobilization

Explanation: Immobilized enzymes refers to enzymes being physically CONFINED to or has been localised in a defined region of space. This ALSO helps them to retain their CATALYTIC activities which can be used continuously. The containment of enzyme solution WITHIN a confined space for the PURPOSE of retaining and re-using enzyme in processing equipment.

Correct ANSWER is (b) False

Best explanation: It will increase. The RATE of enzyme conversion of the substrate will increase with temperature up to an optimum.Above this temperature, enzyme activity will decrease as enzyme denatures. THERMAL denaturation of the enzyme can occur after a certain point of INCREASED temperature.

Right option is (d) The pH of medium AFFECTS the affinity of substrate to enzyme

Easy explanation: Some CASES, the substrate may contain ionic groups, and the pH of medium affects the affinity of substrate to enzyme. This may lead to major changes in the binding of the enzyme to the substrate. This may damage some VITAL REACTIONS in our body.

The correct answer is (a) True

Easy explanation: Variation in pH of MEDIUM result in changes of IONIC form of the active site and activity of enzyme, hence the reaction rate. Variation in pH of medium can also result in changes of the maximum reaction rate, Km stability of the enzyme. Enzyme are active only over small RANGE of pH due to the active site functional group charges (ionic form) and the three dimensional SHAPE of enzyme are pH-dependent.

The correct option is (a) Acidic or basic

The explanation: Certain enzyme have ionic group on their active sites, and these ionic group must be in a suitable FORM (acid or base) to function. Variation in PH of medium result in changes of ionic form of the active site, activity of enzyme, hence the reaction rate, AFFECT the maximum reaction rate, Km STABILITY of the enzyme.

Right answer is (c) Due to the active site FUNCTIONAL GROUP charges

The best I can explain: Enzyme are active only over small range of PH due to the active site functional group charges (ionic FORM) and the three dimensional shape of enzyme are pH-dependent. Certain enzyme have ionic group on their active sites, and these ionic group must be in a suitable form (acid or BASE) to function.

Right ANSWER is (a) 7-8

To EXPLAIN: The OPTIMUM temperature for fermentation should be in the range of 25 to 30°C. The optimum PH range should be in the range of 7.0 and 8.0. High RATE of streptomycin production occurs in the pH range of 7.6 to 8.0.

Right OPTION is (b) BROAD spectrum

For EXPLANATION: STREPTOMYCIN has amino cyclohexanol moiety. It is effective against gram –ve organisms but yet it is broad-spectrum antibiotic. It is used for the treatment of TUBERCULOSIS. Its side effect is nephrotoxicity.

The correct choice is (b) Crystallization

For explanation: Pure metal salts of penicillin can be SAFELY sterilized by dry heat if DESIRED. Thereafter, the aqueous solution of penicillin is subjected to crystallization. The alkali metal salts of penicillin are extremely soluble in WATER, and methods THEREFORE known for crystallizing them have employed organic solvents under nearly anhydrous CONDITIONS.

Correct option is (c) phenylacetic acid

Easiest explanation: Benzylpenicillin (Penicillin G) is a narrow spectrum antibiotic used to treat infections caused by some bacteria. It is a NATURAL penicillin antibiotic administered intravenously or intramuscularly. Penicillin G MAY ALSO be used in CASES such as prophylaxis against susceptible organisms.

The CORRECT OPTION is (a) 6 hrs

Explanation: Growth PHASE is of 40 hrs duration with a doubling time of 6 hrs. Oxygen supply becomes CRITICAL during this phase due to an increase in viscosity of the medium. Production phase duration is 120 to 180 hrs.

The CORRECT option is (C) 6.5

Explanation: The pH should be has to be between 6.4 and 6.8 during the active production phase of penicillin. All the necessary precursors, ammonia, sugar, carbon dioxide, oxygen is controlled, by THOROUGH monitoring of TEMPERATURE and pH for OPTIMAL antibiotic production.

Right ANSWER is (a) GRAM +ve bacteria

Explanation: First discovered by Alexander Fleming in 1929. Natural penicillin is active against a variety of gram +ve bacteria ORGANISMS. They are labile in acids and become inactive when its beta-lactam ring is cleaved by beta-lactamase ENZYME.

The correct option is (C) First on solid media than on liquid media

To ELABORATE: Inoculum development BEGINS on solid media, and then liquid media are used; the media used are specific for inoculum development. Spore SUSPENSION is prepared for inoculum. This will be then transferred to the fermenter.

The correct option is (a) ALEXANDER Fleming

For explanation I would say: The antibiotic penicillin was discovered by Alexander Fleming in 1929, but its commercial production commenced only during the early 1940s. Fleming was ALSO the first to raise a concern about the potential of bacteria developing resistance due to the EXPLOITATION of ANTIBIOTICS, a problem which poses a MAJOR threat to healthcare in this era.

The CORRECT choice is (a) Partial cell recycling

To explain: D = F/V

DILUTION rate is the rate with which substrate is ADDED to a continuous system and products are removed from the system. When dilution rate is HIGHER than maximum GROWTH rate wash out condition occurs in which the cell concentrations progressively decreases. Only way of culturing biomass in the case of wash out is by partially recycling the cells, which were removed from the system.

The correct choice is (d) As impeller speed increases, the bubble size decreases

To explain: As impeller speed increases shear and TURBULENCE increases, this decreases the bubble size. Large bubbles impedes in PROPER mixing of media. But SMALLER bubbles will give better mass TRANSFER.

The correct answer is (d) The breaking of large unstable bubbles

Best explanation: Large WEAK foam bubbles are easily broken by MECHANICAL FORCES (i.e., agitation) and may FORM new tiny bubbles which are much more stable. Tiny bubbles has higher surface area to volume ratio which GIVES more mass transfer.

Correct CHOICE is (a) 0.02 – 0.5

Best EXPLANATION: The substrate TENDS to MAKE lumps which adhere to the inner wall of the fermenter. This phenomenon causes an increase in the value of μmf. Thus, μmf / μf is actually estimated to be 0.02-0.5.

Right answer is (c) Microalgae

For EXPLANATION I would say: Photo-bioreactors are operated in a continuous mode at a TEMPERATURE RANGE of 25-40℃. Microalgae and cyanobacteria are used for this bioprocess most of the times. The organisms will be growing during day light while the products are produced during night.

The correct OPTION is (a) Does not allow accumulation of products

Explanation: It’s a difficult task to control the pH of packed BED BIOREACTORS by the adding ACID or alkali because of poor mixing. These bioreactors are preferred for bioprocessing technology involving product-inhibited reactions SINCE the packed bed bioreactors does not allow accumulation of the products.

The CORRECT answer is (d) Weight of solid particles

The explanation is: For an efficient operation of fluidized BEDS, gas is sparged to create a SUITABLE and optimised gas-liquid-solid fluid bed. It is necessary to KEEP in mind that the suspended solid particles are not too LIGHT or too dense (too light ones may float whereas to dense ones may settle at the bottom), and they should stay in a good suspended state.

Right option is (a) True

For explanation I would SAY: In two-stage airlift bioreactors growing cells from one BIOREACTOR (maintained at temperature 30℃) are pumped into another bioreactor (at temperature 42°C). Since the temperature cannot be ABRUPTLY very QUICKLY increased from 30℃ to 42℃ there is a necessity for the two-stages.

The correct answer is (b) False

Easiest explanation: Internal loop BIOREACTOR creates an internal LIQUID CIRCULATION channel. It has a SINGLE container and has a central draft tube that creates interior liquid circulation channel. External loop AIRLIFT bioreactor has an external loop where the liquid circulate through separate independent channels.

The correct choice is (a) More EFFICIENT than bubble column reactors

The explanation: Airlift bioreactors are more efficient than bubble COLUMNS. This is particularly true for denser suspension of microorganisms. The mixing of the contents is BETTER than the bubble column than any other BIOREACTOR.

Right choice is (c) 4-6

To explain: Air or gas sparged inside a bioreactor such an AD BUBBLE column reactor through the use of PERFORATED pipes or plates are called spargers. The FLOW rate of the air/gas INFLUENCES the some factors —O2 transfer, mixing. The bubble column bioreactors may be fitted with perforated plates to improve its performance. The vessel used for bubble column bioreactors is usually cylindrical and has an aspect ratio of 4-6 (i.e., height to diameter ratio).

The correct ANSWER is (d) Homogenisation, mixing, breaking bubbles

The explanation is: Bioreactors are CYLINDRICAL vessels with a motor driven shaft that supports one or more impellers or agitators. The bubbles which are generated by the sparger are bigger and has to be broken down to smaller bubbles by the USE of impellers. This LEADS to a UNIFORM and homogeneous environment throughout the bioreactor.

Correct choice is (a) Proper gas distribution

The best explanation: A device known as the SPARGER is used to sparge in air inside a STIRRED tank reactor or a short stirred tank reactor. There are different kinds of sparger available. It can be ring with many holes, a tube with single orifice. Spargers and impellers enables BETTER gas distribution throughout the VESSEL.