Question: What is one difference between a Bt crop and an organically-grown crop that is sprayed with Bt?
Answer Options: The organically-grown crops are better protected from insects because they typically have more Bt on them than do Bt crops. In Bt crops, the pesticide is made throughout the plant while in organically-grown crops, the Bt is only on the surfaces that were sprayed. Bt crops only have Bt in them as seedlings, while organically-grown crops can be sprayed with Bt at any point in their growth cycle. Bt is an insecticide and so cannot be used on organically-grown crops. Correct Answer: In Bt crops, the pesticide is made throughout the plant while in organically-grown crops, the Bt is only on the surfaces that were sprayed.
Question: How does the Bt toxin stop insects from feeding on plants?
Answer Options: It breaks down the exoskeleton of the insect. It makes holes in the insect gut. It has an unpleasant taste. It makes holes in the lungs, making breathing difficult. Correct Answer: It makes holes in the insect gut.
Question: “In the video ‘Bacillus thuringiensis bacterium and the Bt toxin’, it is stated that scientists know that the Bt bacterium can reproduce in humans and in water (such as ponds) and that the Bt toxin harms human guts.” The preceding statement is…
Answer Options: True False Correct Answer: False
Question: “Because some Bt toxins are good for killing one type of insect while other varieties of Bt toxins are good for killing another type of insect, multiple different Bt genes are sometimes put into a single plant to protect them from multiple types of insects.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: The refuge strategy is one method farmers use to try to limit the spread of Bt-resistant insects. How does it work?
Answer Options: Non-Bt crops are planted in close proximity to Bt crops to protect the non-Bt crops from insect damage and reduce the number of Bt crops needed. It involves placement of pheromone traps on the outskirts of farms to kill Bt-resistant insects that try to leave. It allows Bt-resistant insects to mate with Bt-sensitive insects instead of other Bt-resistant insects, to produce offspring that are Bt-sensitive. It doesn’t work – it is an outdated strategy that most farmers have now replaced with more modern techniques. Correct Answer: It allows Bt-resistant insects to mate with Bt-sensitive insects instead of other Bt-resistant insects, to produce offspring that are Bt-sensitive
Question: Some laundry detergents contain multiple enzymes, including proteases. What is the implication of the presence of the proteases for the other enzymes in the laundry detergent?
Answer Options: Proteases can leave a residue on clothes that attracts dirt; the other enzymes are added to break down that dirt. Most enzymes are proteins and so the protease could degrade the other enzymes unless they are chosen for being resistant to the protease, or the enzymes are otherwise protected from the protease. The other enzymes coat the proteases, making it harder for any of the enzymes to do their jobs. Proteases cause ‘pilling’ on clothes, making the clothes look fuzzy and faded. Correct Answer: Most enzymes are proteins and so the protease could degrade the other enzymes unless they are chosen for being resistant to the protease, or the enzymes are otherwise protected from the protease.
Question: “Surfactants help clean oil stains on laundry treated with lipases by lifting off the products of the lipase reaction: monoglycerides, diglycerides, and fatty acids.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: What is phytate?
Answer Options: Phytate is a form of phosphorus that is found in cereal grains, corn, and soybeans. Phytate is an enzyme found in the bacteria that live in the rumens of some animals. Phytate is a herbicide that prevents algal blooms and eutrophication in bodies of water, such as ponds. Phytate promotes the absorption of minerals such as calcium and iron in non-ruminant animals and is thus an essential nutrient for those animals. Correct Answer: Phytate is a form of phosphorus that is found in cereal grains, corn, and soybeans.
Question: “If an enzyme is heat-tolerant, it can be mixed in and pelleted with the other ingredients in animal feed; if the enzyme is not heat-tolerant, it can be added as a coating to pre-pelleted feed.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: When enzyme companies are choosing and testing a new enzyme product, which of the following do they need to consider? Select ALL that apply.
Answer Options: How well the enzyme will perform for the company’s customers. How well the enzyme will work at the temperatures used in the application for which the enzyme is intended. How well the enzyme will retain its activity during storage (i.e., whether or not it is ‘shelf stable’). How well the enzyme will retain its activity in the presence of the other ingredients in the final product. Correct Answer: How well the enzyme will perform for the company’s customers. How well the enzyme will work at the temperatures used in the application for which the enzyme is intended. How well the enzyme will retain its activity during storage (i.e., whether or not it is ‘shelf stable’). How well the enzyme will retain its activity in the presence of the other ingredients in the final product.
Question: While enzymes are found naturally in living organisms, they can also be commercially produced for use in industrial applications. What kinds of industrial applications can enzymes be used in or not be used in?
Answer Options: Enzymes cannot be used in food applications because they are considered to be ‘chemicals’ and thus unsafe for consumption. Enzymes are used in a wide variety of applications, including animal feed, consumer products, paper production, and wastewater treatment. Enzymes are used commercially in reactions where one product is made by combining two or more substrates, but not in reactions where two or more products are made by breaking down one substrate. Enzymes are used in many ‘modern’ applications, but not older applications. This is because we only recently discovered them. Correct Answer: Enzymes are used in a wide variety of applications, including animal feed, consumer products, paper production, and wastewater treatment.
Question: Match the descriptions to the enzymes.
Answer Options: Amylase Phytase Protease Lipase Cellulase Correct Answer: Amylase – An enzyme that degrades starch and that can produce sugars for germinating seedlings. Phytase – An enzyme used in animal feed to reduce phosphorus in manure. Protease – An enzyme used to break down plant cell walls when waste plant material is used to make bioethanol. Lipase – An enzyme produced by the pancreas to help break down dietary fats in our body. Cellulase – An enzyme that is sometimes extracted from papaya and pineapples and sold as a digestion-aiding supplement.
Question: What is one reason that enzymes are sometimes added to the dough in commercial bread baking?
Answer Options: Enzymes are needed to degrade gluten, to make commercial bread more nutritious and better able to meet the required nutritional standards. Enzymes are needed to make gluten, which is a protein found in conventional bread dough that traps air (carbon dioxide) bubbles made by yeast. There are some natural enzymes found in flour, but commercial bread bakers often add additional enzymes to improve certain qualities of bread, such as its uniformity. Lipases are sometimes added to bread dough to breakdown the proteins in bread, making the bread softer. Correct Answer: There are some natural enzymes found in flour, but commercial bread bakers often add additional enzymes to improve certain qualities of bread, such as its uniformity.
Question: “In place of lipase, commercial bread bakers can add one or more emulsifiers, such as DATEM or monoglycerides, to their bread dough.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: How is cellulosic biomass used to make biofuels?
Answer Options: It isn’t – we haven’t figured out how to use it yet, though we want to because it is so abundant. The sap from the plants is collected and concentrated before being used as a direct, drop-in replacement biofuel. Enzymes, like cellulase, are used to break down the cellulosic biomass into sugars that can be used by microbes to make bioethanol. The starch in the plant materials is converted to sugars using amylase and the sugars are then chemically converted to ethanol using the Haber-Bosch process. Correct Answer: Enzymes, like cellulase, are used to break down the cellulosic biomass into sugars that can be used by microbes to make bioethanol.
Question: Dedicated energy crops are crops that could be grown solely to be used to make biofuels, and not food/feed. Which of the following is a true limitation or benefit of using them in the United States?
Answer Options: They require a lot of plowing, weeding, and fertilizing and so farming them produces more carbon dioxide than they remove from the atmosphere when they’re growing. They are all annual plants, meaning they would have to be planted again each year. They are used to produce bioethanol, which will not be able to provide all our energy needs or replace fossil fuels completely. Energy cane is a particularly important dedicated energy crop in the USA because it can be grown in the arid western states, where few other crops can be grown. Correct Answer: They are used to produce bioethanol, which will not be able to provide all our energy needs or replace fossil fuels completely.
Question: How are algae typically used to make biofuels?
Answer Options: They are collected from ponds and other waterways then buried underground for 5-10 years, at which point they have become analogous to fossil fuel. Algae photosynthesize and, in so doing, generate energy from the sun directly into biofuels that can be extracted and used as a ‘drop-in’ replacement for some petroleum products. They consume sugars that can be made from corn starch or cellulose and produce ethanol. Correct Answer: Algae photosynthesize and, in so doing, generate energy from the sun directly into biofuels that can be extracted and used as a ‘drop-in’ replacement for some petroleum products.
Question: “Biofuels will be more competitive, economically, when fossil crude oil prices drop.” The preceding statement is…
Answer Options: True False Correct Answer: False
Question: Which of the following statements about biofuels is UNTRUE and was thus not discussed in the video, “Why don’t we have functional biofuels yet?”
Answer Options: One idea for using biofuels in the future is to reserve their use for vessels/machines with larger engines, such as cargo ships and airplanes, and to rely on battery-powered engines for smaller vessels/machines, such as cars and small trucks. Brazil has been quite successful at making bioethanol from sugarcane. Used grease and oil from the restaurant industry can be used to make biodiesel. “1st generation” bioethanol was designed to address some of the problems associated with corn-based bioethanol. Correct Answer: “1st generation” bioethanol was designed to address some of the problems associated with corn-based bioethanol.