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An enzyme-catalyzed reaction follows standard Michaelis-Menten kinetics with a maximum velocity Vmax = 120 μmol/(min·mg) and a Michaelis constant Km = 4.0 mM. What is the initial reaction rate (v) when the substrate concentration [S] is 6.0 mM?

Sistemas Biologicos Y Herramientas Analiticas

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A Lineweaver-Burk double-reciprocal plot (1/v versus 1/[S]) yields a straight line described by the linear regression equation y = 0.25x + 0.05, where 1/v is in (μmol/min)⁻¹ and 1/[S] is in mM⁻¹. What are the values of Vmax and Km for this enzymatic system?

Sistemas Biologicos Y Herramientas Analiticas

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A purified recombinant industrial biocatalyst is evaluated in the presence of a reversible inhibitor. Kinetic assays indicate that the apparent Km increases from 2.5 mM to 7.5 mM, while the maximum velocity Vmax remains unchanged at 150 μmol/(min·mg). Which type of inhibition does this observation demonstrate?

Sistemas Biologicos Y Herramientas Analiticas

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A solution of a purified therapeutic single-chain antibody fragment (molar mass = 28,000 g/mol) is analyzed in a 1.00 cm path length quartz cuvette. At 280 nm, the absorbance is 0.840. Given a theoretical molar absorptivity (extinction coefficient) ε280 = 42,000 M⁻¹·cm⁻¹, what is the mass concentration of the antibody fragment in mg/mL?

Sistemas Biologicos Y Herramientas Analiticas

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A sample from a high-cell-density bioreactor culture of Escherichia coli is diluted for spectrophotometric quantification. A 0.20 mL aliquot of the culture broth is diluted with physiological saline to a final volume of 5.00 mL. The optical density at 600 nm (OD600) of this diluted sample is measured as 0.360 in the linear range. What is the true OD600 of the original fermentation broth?

Sistemas Biologicos Y Herramientas Analiticas

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In SDS-PAGE analysis of proteins, sodium dodecyl sulfate (SDS) and beta-mercaptoethanol (or DTT) perform distinct roles during sample preparation. Which statement accurately describes the specific molecular function of beta-mercaptoethanol in this analytical technique?

Sistemas Biologicos Y Herramientas Analiticas

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When designing a plasmid expression vector for high-level recombinant protein synthesis in Escherichia coli, which regulatory element must be placed upstream of the start codon (ATG) to ensure efficient recruitment and positioning of the 30S ribosomal subunit on the mRNA transcript?

Sistemas Biologicos Y Herramientas Analiticas

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A biotechnology research team aims to insert a 1.8 kb gene encoding an industrial xylanase into an expression plasmid. They choose to digest both the insert and vector with two different restriction enzymes that generate non-complementary sticky ends (e.g., EcoRI and HindIII). What is the primary operational advantage of this dual-digestion cloning strategy?

Sistemas Biologicos Y Herramientas Analiticas

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During aerobic batch fermentation of Saccharomyces cerevisiae for bioethanol or baker's yeast production, high concentrations of glucose (>0.15 g/L) lead to ethanol formation despite fully aerobic conditions and high dissolved oxygen levels. Which physiological phenomenon causes this metabolic overflow?

Sistemas Biologicos Y Herramientas Analiticas

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A culture of Escherichia coli is inoculated into a minimal medium containing both glucose and lactose. The culture exhibits diauxic growth with two distinct exponential phases separated by a lag period. What molecular mechanism accounts for the preferential consumption of glucose and the temporary silencing of the lac operon during the first phase?

Sistemas Biologicos Y Herramientas Analiticas

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In the industrial production of primary metabolites such as L-lysine by Corynebacterium glutamicum, wild-type strains exhibit tight feedback inhibition of aspartate kinase by threonine plus lysine. Which genetic improvement strategy is traditionally employed to overcome this regulatory bottleneck?

Sistemas Biologicos Y Herramientas Analiticas

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Reverse-phase high-performance liquid chromatography (RP-HPLC) is used to analyze a mixture of peptides. The stationary phase consists of silica particles functionalized with octadecylsilane (C18), and the mobile phase uses an aqueous 0.1% trifluoroacetic acid (TFA) solution with an increasing acetonitrile gradient. In what order will peptides generally elute?

Sistemas Biologicos Y Herramientas Analiticas

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A recombinant biopharmaceutical protein is produced in Chinese Hamster Ovary (CHO) cells. During post-translational characterization, which analytical technique coupled to mass spectrometry is the gold standard for profiling complex N-linked glycan structures and verifying site-specific macro- and micro-heterogeneity?

Sistemas Biologicos Y Herramientas Analiticas

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In quantitative reverse transcription PCR (RT-qPCR), what does the quantification cycle (Cq or Ct value) represent, and how does it correlate with the initial abundance of target mRNA transcript in the biological sample?

Sistemas Biologicos Y Herramientas Analiticas

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In recombinant protein production using the pET expression system in Escherichia coli BL21(DE3), which inducer is conventionally added to initiate transcription, and what is its specific molecular target?

Sistemas Biologicos Y Herramientas Analiticas

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A biotechnologist evaluates an enzyme exhibiting pure non-competitive inhibition. When an inhibitor concentration [I] = 3.0 mM is introduced, how do the kinetic parameters Vmax and Km compare to those of the uninhibited enzyme?

Sistemas Biologicos Y Herramientas Analiticas

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Which molecular technique allows the simultaneous relative quantification of thousands of mRNA transcripts across differing bioprocess conditions by sequencing cDNA libraries at high depth?

Sistemas Biologicos Y Herramientas Analiticas

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In the CRISPR-Cas9 genome editing system derived from Streptococcus pyogenes, what is the critical requirement of the protospacer adjacent motif (PAM) for Cas9 endonuclease double-strand DNA cleavage?

Sistemas Biologicos Y Herramientas Analiticas

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A stock solution of bovine serum albumin (BSA) has a concentration of 10.0 mg/mL. A bioprocess analyst prepares a standard calibration point by pipetting 50 μL of stock BSA and adding analytical buffer to reach a total volume of 1.00 mL. What is the final concentration of this calibration standard?

Sistemas Biologicos Y Herramientas Analiticas

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In microbial strain development for secondary metabolite production (e.g., penicillin by Penicillium chrysogenum), secondary metabolites are primarily biosynthesized during which growth phase in a batch culture?

Sistemas Biologicos Y Herramientas Analiticas

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A recombinant intracellular industrial enzyme is expressed in E. coli. When cell lysate is analyzed by SDS-PAGE, a dense band appears in the insoluble pellet fraction after centrifugation, but no activity is found in the soluble supernatant. Microscopic analysis confirms the presence of refractive cytoplasmic aggregates. What bioprocess phenomenon has occurred?

Sistemas Biologicos Y Herramientas Analiticas

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Which analytical technique allows the direct determination of the molecular mass of intact proteins and biomacromolecules with minimal fragmentation by embedding the analyte in an organic matrix and ionizing with a pulsed nitrogen or Nd:YAG laser?

Sistemas Biologicos Y Herramientas Analiticas

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In an uncompetitive enzyme inhibition model, how do the apparent kinetic constants Vmax,app and Km,app change as the inhibitor concentration [I] increases?

Sistemas Biologicos Y Herramientas Analiticas

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A recombinant bioprocess uses an auxotrophic strain of E. coli unable to synthesize leucine (Leu⁻). If this strain is grown in a chemostat with excess glucose and limiting leucine, what is the primary phenotypic consequence?

Sistemas Biologicos Y Herramientas Analiticas

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In the construction of a cDNA library from eukaryotic cells producing an industrial cellulase, why is reverse transcriptase utilized instead of directly cloning the genomic DNA sequence into a standard bacterial expression vector?

Sistemas Biologicos Y Herramientas Analiticas

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An industrial strain of Bacillus subtilis cultivated in a batch fermenter exhibits an exponential specific growth rate μ = 0.462 h⁻¹. Assuming balanced exponential growth, what is the doubling time (td) of the culture?

Ingenieria De Produccion Biotecnologica

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A 1,000 L working-volume batch bioreactor is loaded with media containing 40.0 g/L of glucose. At the end of the exponential phase, the glucose is completely consumed. If the microbial biomass yield coefficient on substrate is Yx/s = 0.45 g dry cells / g glucose and the initial inoculum concentration was 1.0 g/L, what total mass of dry cell biomass is generated (excluding the inoculum) in kilograms?

Ingenieria De Produccion Biotecnologica

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In an aerobic bioreactor, the dissolved oxygen concentration in the liquid broth is maintained at CL = 2.0 mg/L. The equilibrium dissolved oxygen saturation concentration under operating conditions is C* = 8.0 mg/L. If the volumetric oxygen mass transfer coefficient is measured as kLa = 180 h⁻¹ (0.05 s⁻¹), what is the volumetric oxygen transfer rate (OTR) in g/(L·h)?

Ingenieria De Produccion Biotecnologica

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A 5,000 L industrial fermenter contains nutrient medium with an initial bioburden of 2.0 × 10⁵ heat-resistant bacterial spores per mL. In accordance with bioprocess validation criteria, the acceptable sterilization failure risk is specified as Nt = 10⁻³ surviving spores per batch (one contaminated batch per 1,000 runs). What is the required thermal sterilization Del factor (criterion ∇)?

Ingenieria De Produccion Biotecnologica

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A continuous stirred-tank bioreactor (chemostat) operates without cell recycle at steady state with a working liquid volume of 600 L and a sterile feed flow rate of 150 L/h. What is the specific growth rate (μ) of the microbial culture inside the reactor?

Ingenieria De Produccion Biotecnologica

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A microbial culture exhibits Monod growth kinetics with a maximum specific growth rate μmax = 0.80 h⁻¹ and a Monod saturation constant Ks = 0.20 g/L. What is the specific growth rate (μ) when the limiting substrate concentration in the bioreactor is 0.60 g/L?

Ingenieria De Produccion Biotecnologica

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A standard Rushton 6-blade disc turbine impeller with a diameter Di = 0.40 m is operated in a bioreactor filled with an aqueous fermentation broth (density ρ = 1,000 kg/m³, dynamic viscosity μ = 0.001 Pa·s) at an agitation speed N = 3.0 rev/s (180 rpm). What is the impeller Reynolds number (Re), and what hydrodynamic flow regime does it establish?

Ingenieria De Produccion Biotecnologica

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In glycolysis (the Embden–Meyerhof–Parnas pathway), what is the net yield per molecule of glucose?

Sistemas Biologicos Y Herramientas Analiticas

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In continuous bioreactor culture, the washout phenomenon occurs when the dilution rate D exceeds a critical threshold Dcrit. What defines the physiological state of the bioreactor at washout?

Ingenieria De Produccion Biotecnologica

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Why is continuous High-Temperature Short-Time (HTST) thermal sterilization of fermentation media preferred over in situ batch sterilization in large-scale industrial bioprocesses?

Ingenieria De Produccion Biotecnologica

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The Luedeking-Piret kinetic model defines the specific rate of product formation as qp = α·μ + β. In the industrial production of ethanol or lactic acid during primary exponential growth, which term dominates and how is the bioproduct classified?

Ingenieria De Produccion Biotecnologica

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During the scale-up of an aerated stirred-tank bioreactor from 10 L pilot scale to 10,000 L industrial scale, which scale-up criterion is most frequently held constant to ensure equivalent oxygen transfer performance without causing excessive hydrodynamic shear or foaming?

Ingenieria De Produccion Biotecnologica

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In constant-pressure cake filtration of a cell suspension, the Ruth equation (neglecting filter-medium resistance) gives t = (µ·α·c / (2·A²·ΔP))·V². If the filter area A is doubled while the pressure, suspension and filtrate volume stay the same, how does the filtration time change?

Ingenieria De Los Bioprocesos Y Caracterizacion

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An ultrafiltration step must concentrate a globular enzyme of 60 kDa with high retention. Which nominal membrane molecular weight cut-off (MWCO) is the most appropriate choice?

Ingenieria De Los Bioprocesos Y Caracterizacion

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In the dynamic 'gassing-out' method for measuring the volumetric oxygen transfer coefficient (kLa) in a bioreactor containing active respiring cells, what is the procedure during the measurement phase?

Ingenieria De Produccion Biotecnologica

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In high-cell-density fed-batch fermentation of recombinant E. coli, why is exponential feeding of glucose implemented instead of a constant-rate feed?

Ingenieria De Produccion Biotecnologica

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A double-stranded DNA sample from a production strain contains 30% adenine (as a fraction of all bases). According to Chargaff's rules, what percentage of its bases are guanine?

Sistemas Biologicos Y Herramientas Analiticas

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A microbial growth curve in a batch bioreactor displays the following sequential phases: lag, acceleration, exponential, deceleration, stationary, and death. In which phase is the specific growth rate μ strictly constant and at its maximum value for the prevailing environmental conditions?

Sistemas Biologicos Y Herramientas Analiticas

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In the Andrews (Haldane) substrate inhibition model, the specific growth rate is expressed as μ = (μmax · S) / (Ks + S + S² / Ki). If the substrate inhibition constant Ki = 25 g/L and Ks = 0.25 g/L, at what substrate concentration S* does the maximum achievable specific growth rate occur?

Ingenieria De Produccion Biotecnologica

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A photobioreactor designed for cultivating microalgae (e.g., Chlorella vulgaris or Haematococcus pluvialis) requires high photosynthetic photon flux efficiency. Why are narrow-tubular or flat-panel designs utilized rather than deep cylindrical stirred vessels?

Ingenieria De Produccion Biotecnologica

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In microbial energetic stoichiometry, the respiratory quotient (RQ) is defined as the molar ratio of carbon dioxide produced to oxygen consumed (RQ = CER / OUR). If an aerobic culture growing on glucose exhibits an RQ = 1.05 that abruptly shifts to RQ = 2.40, what operational disturbance has most likely occurred?

Sistemas Biologicos Y Herramientas Analiticas

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A Protein A capture column must process 150 g of monoclonal antibody per cycle. The resin's dynamic binding capacity (DBC, at 10% breakthrough) is 40 g/L, and the process loads to 80% of the DBC as a safety margin. What minimum resin volume is required?

Ingenieria De Los Bioprocesos Y Caracterizacion

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A stirred bioreactor operating in the turbulent regime (Re > 10⁴) has an un-gassed power number Np = 5.0 for a Rushton turbine. If the impeller diameter Di is 0.50 m, agitation speed N = 4.0 rev/s, and broth density ρ = 1,000 kg/m³, what is the mechanical power P0 consumed by the impeller in watts?

Ingenieria De Produccion Biotecnologica

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