Industrial Enzymes Practice Questions
20 free Industrial Enzymes practice questions for the Microbiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following enzymes is primarily used in the detergent industry to remove protein-based stains like blood and grass?
- A Amylases
- B Lipases
- C Proteases
- D Cellulases
Correct answer: Proteases
Proteases break down peptide bonds in proteins, converting them into smaller, soluble peptides or amino acids. This makes them highly effective at removing organic, proteinaceous stains from fabrics during laundry processes.
The production of High Fructose Corn Syrup (HFCS) relies on which enzyme to convert glucose into its sweeter isomer, fructose?
- A Alpha-amylase
- B Glucose isomerase
- C Glucoamylase
- D Phosphoglucose isomerase
Correct answer: Glucose isomerase
Glucose isomerase (also known as xylose isomerase) catalyzes the reversible isomerization of D-glucose to D-fructose. This is a critical step in the food industry to increase the sweetness profile of starch-derived syrups.
Which microorganism is a major industrial source for the production of heat-stable alpha-amylases?
- A Saccharomyces cerevisiae
- B Bacillus licheniformis
- C Escherichia coli
- D Aspergillus niger
Correct answer: Bacillus licheniformis
Bacillus licheniformis is widely used to produce alpha-amylases that remain active at high temperatures (liquefaction). This thermostability is essential for the initial breakdown of starch in industrial processes.
In the textile industry, the process of 'biopolishing' to remove cotton fuzz and prevent pilling is achieved using which enzyme?
- A Pectinase
- B Laccase
- C Cellulase
- D Xylanase
Correct answer: Cellulase
Cellulases partially hydrolyze the surface of cotton fibers, removing microfibrils that cause a fuzzy texture. This results in a smoother fabric surface, brighter colors, and increased resistance to pilling.
Which enzyme is used in the dairy industry as a microbial alternative to calf rennet for cheese curdling?
- A Lactase
- B Chymosin
- C Catalase
- D Lipoxygenase
Correct answer: Chymosin
Chymosin (or rennin) is a protease that specifically cleaves kappa-casein in milk, leading to coagulation. Modern industrial chymosin is often produced via recombinant DNA technology in yeasts or fungi.
What is the primary role of pectinases in the fruit juice industry?
- A To increase the vitamin C content
- B To clarify the juice and improve extraction yield
- C To prevent the juice from fermenting into alcohol
- D To add a sweet flavor to the juice
Correct answer: To clarify the juice and improve extraction yield
Pectin is a structural polysaccharide in plant cell walls that makes juice cloudy and viscous. Pectinases break down these molecules, reducing viscosity and allowing for better filtration and higher juice yields.
The 'Stonewashed' look of denim jeans is now primarily achieved using enzymes rather than pumice stones. Which enzyme is responsible?
- A Amylase
- B Pectinase
- C Cellulase
- D Protease
Correct answer: Cellulase
Cellulases act on the surface of indigo-dyed denim, loosening the dye and creating the faded, worn look. This 'bio-stoning' process is more environmentally friendly and causes less mechanical damage to the fabric and machines.
Which enzyme is added to bread dough to improve volume, crust color, and anti-staling properties by breaking down starch?
- A Transglutaminase
- B Glucoamylase
- C Beta-glucanase
- D Alpha-amylase
Correct answer: Alpha-amylase
Alpha-amylases break down starch into fermentable sugars (maltose), which provides food for yeast. This improves gas production for better volume and produces sugars that caramelize to enhance crust color.
Enzyme immobilization is a common industrial practice. What is its main advantage?
- A It increases the amount of enzyme needed
- B It makes the enzyme more sensitive to pH changes
- C It prevents the enzyme from binding to the substrate
- D It allows for the recovery and reuse of the enzyme
Correct answer: It allows for the recovery and reuse of the enzyme
Immobilizing enzymes on solid supports allows them to be easily separated from the product stream. This enables continuous processing, reduces costs through reuse, and often improves the stability of the enzyme.
Which enzyme is used to produce lactose-free milk for individuals with lactose intolerance?
- A Beta-galactosidase
- B Alpha-glucosidase
- C Beta-fructosidase
- D Alpha-galactosidase
Correct answer: Beta-galactosidase
Beta-galactosidase (lactase) hydrolyzes the disaccharide lactose into the monosaccharides glucose and galactose. This pre-digestion makes the milk safe for consumption by people who lack the endogenous enzyme.
In the leather industry, 'bating' is a process that makes hides soft and supple. Which enzymes are used for this?
- A Lipases and Amylases
- B Amylases and Pectinases
- C Xylanases and Laccases
- D Proteases and Lipases
Correct answer: Proteases and Lipases
Proteases remove non-collagenous proteins, while lipases remove fats and grease from the hides. This combined enzymatic action opens up the fiber structure, resulting in a cleaner and more pliable leather.
Which of the following is a key advantage of using microbial enzymes over traditional chemical catalysts?
- A They require high pressure and temperature
- B They have low specificity for substrates
- C They work under mild conditions and are biodegradable
- D They produce toxic byproducts and pollute the environment
Correct answer: They work under mild conditions and are biodegradable
Microbial enzymes are highly specific and efficient at ambient temperatures and neutral pH. Using 'white biotechnology' reduces energy consumption and the environmental footprint compared to harsh chemical alternatives.
Which enzyme is used in 'bio-bleaching' within the pulp and paper industry to reduce the need for chlorine?
- A Cellulase
- B Amylase
- C Invertase
- D Xylanase
Correct answer: Xylanase
Xylanases degrade hemicellulose (xylan) that traps lignin in the wood pulp. By breaking down xylan, lignin becomes easier to remove, which significantly reduces the amount of chlorine-based bleaching agents required.
Industrial production of acrylamide from acrylonitrile is catalyzed by which microbial enzyme?
- A Nitrile hydratase
- B Cyanide hydratase
- C Nitrate reductase
- D Amide hydrolase
Correct answer: Nitrile hydratase
Nitrile hydratase, often produced by Rhodococcus rhodochrous, is used in a massive-scale biocatalytic process. It converts acrylonitrile to acrylamide with nearly 100% yield and high purity under mild conditions.
Extremozymes are enzymes derived from microbes that live in harsh environments. Which of these would be most useful for a process requiring high salt concentrations?
- A Barophiles
- B Thermophiles
- C Halophiles
- D Acidophiles
Correct answer: Halophiles
Halophiles are organisms that thrive in high-salinity environments. Their enzymes, or halozymes, are evolved to maintain structural integrity and catalytic activity even in the presence of high salt concentrations.
Which enzyme is commonly used to remove hydrogen peroxide residues after textile bleaching?
- A Peroxidase
- B Superoxide dismutase
- C Oxidase
- D Catalase
Correct answer: Catalase
Catalase efficiently breaks down hydrogen peroxide into water and oxygen. In the textile industry, this prevents the peroxide from interfering with subsequent dyeing steps, saving water and time compared to multiple rinses.
The enzyme 'Phytase' is added to animal feed primarily to:
- A Increase the fat content of the meat
- B Preserve the feed from fungal spoilage
- C Make the feed smell better to the animals
- D Release phosphorus from plant phytic acid
Correct answer: Release phosphorus from plant phytic acid
Monogastric animals cannot digest phytic acid, the storage form of phosphorus in plants. Adding phytase releases this phosphorus, improving nutrition and reducing phosphorus pollution in animal waste.
Which fungal genus is the primary source of industrial-scale Glucoamylase production?
- A Aspergillus
- B Penicillium
- C Rhizopus
- D Candida
Correct answer: Aspergillus
Aspergillus niger is the leading industrial producer of glucoamylase. This enzyme is crucial for the saccharification step, where it breaks down starch dextrins into individual glucose units.
What is the function of the enzyme 'Invertase' in the confectionery industry?
- A To create liquid centers in chocolates
- B To increase the hardness of candy bars
- C To prevent sugar from dissolving
- D To prevent chocolate from melting quickly
Correct answer: To create liquid centers in chocolates
Invertase breaks down sucrose into glucose and fructose (invert sugar). When added to a solid fondant center in chocolate, it gradually liquefies the sucrose, creating a smooth, liquid filling.
Lipases used in the synthesis of biodiesel facilitate which chemical reaction?
- A Transesterification of triglycerides
- B Alcoholic fermentation of simple sugars
- C Hydrolysis of plant cellulose
- D Oxidation of methane to carbon dioxide
Correct answer: Transesterification of triglycerides
Lipases catalyze the transesterification of oils (triglycerides) with alcohols to produce fatty acid methyl esters (biodiesel). This enzymatic route is cleaner and requires less energy than traditional base-catalyzed methods.