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Enzymes consist of nucleic acid No worries! We‘ve got your back. Try BYJU‘S free classes today! Enzymes are carbohydrates. No worries! We‘ve got your back. Try BYJU‘S free classes today! Enzymes have all these properties No worries! We‘ve got your back. Try BYJU‘S free classes today! Enzymes have optimum activity at body temperature Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses Open in App Solution The correct option is DEnzymes have optimum activity at body temperatureEnzymes have maximum efficiency at body temperature.No worries! We‘ve got your back. Try BYJU‘S free classes today! Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses No worries! We‘ve got your back. Try BYJU‘S free classes today! Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses Open in App Solution The correct option is D ProteinsEnzymes are the biocatalyst which help in different processes occurring in our body like digestion of food.Enzymes are proteins which act as biocatalyst having specific role/action in specific biochemical reaction. For example, the enzyme that catalyzes the hydrolysis of maltose into glucose is named as maltase. C12H22O11+H2OMaltase−−−−−→2C6H12O6MaltoseGlucoseAlmost all the enzymes are globular proteins. Hence, the correct options are (A) and (D).Updated On: 27-06-2022 (00 : 00) Video Solution: Which of the following statements about enzymes are correct ? (i) Enzymes do not alter the overall change in free energy for a reaction. (ii) Enzymes are proteins whose three dimensional energy. (iii) Enzymes speed up reactions by lowering activation energy. (iv) Enzymes are highly specific for reactions. (v) The energy input needed to start a chemical reaction is called activation energy.All MCAT Biology ResourcesIn 2013, scientists linked a cellular response called the unfolded protein response (UPR) to a series of neurodegenerative diseases, including such major health issues as Parkinson’s and Alzheimer’s Disease. According to their work, the unfolded protein response is a reduction in translation as a result of a series of enzymes that modify a translation initiation factor, eIF2, as below: In the above sequence, the unfolded protein sensor binds to unfolded protein, such as the pathogenic amyloid-beta found in the brains of Alzheimer’s Disease patients. This sensor then phosphorylates PERK, or protein kinase RNA-like endoplasmic reticulum kinase. This leads to downstream effects on eIF2, inhibition of which represses translation. It is thought that symptoms of neurodegenerative disease may be a result of this reduced translation. We do not know the exact action of eIF2 after it has been acted upon by PERK, and therefore cannot draw conclusions about the phosphorylation or dephosphorylation of transcription factors. Which of the following is most likely the molecular event that causes repression of translation, based on the information in the passage? Possible Answers: Dephosphorylation of eIF2 Phosphorylation of the unfolded proteins Phosphorylation of eIF2 Phosphorylation of transcription factors Dephosphorylation of transcription factors Correct answer: Phosphorylation of eIF2 Explanation: The diagram in the passage shows the kinase PERK, which must phosphorylate its substrate, acts on eIF2. Based on its kinase nature and the diagram, phosphorylation of eIF2 is the most likely answer that would lead to propagation of the signal shown. Which of the following statements about enzymes is false? Possible Answers: Harsh, acidic conditions can completely denature an enzyme An enzyme is completely converted to product during metabolism The Keq of a reaction remains unchanged in the presence of an enzyme Enzymes speed up the rate of reaction in DNA synthesis Correct answer: An enzyme is completely converted to product during metabolism Explanation: While enzymes do not change the amount of product formed in a reaction (no change to Keq) they do speed up the rate of reaction. It is also true that under certain conditions pH and/or heat can denature an enzyme. During a reaction, an enzyme does not get used up and is regenerated; enzymes are a type catalyst. Essentially, the enzyme is both a reactant and a product of the reaction it catalyzes. Enzymes are proteins that catalyze the biological reactions in the body. Every enzyme has a unique set of conditions in which it functions optimally. The function of an enzyme can be plotted on a graph, with the functionality of the enzyme on the y-axis, and the factor being manipulated on the x-axis. What shape would you expect the graph for an enzyme to look like with temperature as the factor being manipulated? Possible Answers: A bell shaped curve A straight line with a positive slope An exponential curve A straight line with a negative slope Correct answer: A bell shaped curve Explanation: Keep in mind that enzymes are proteins. They will increase in efficiency as temperature increases, but eventually too much heat will start to denature the protein. As a result, the graph will climb to maximum effeciency at a specific temperature. After that peak, it will decrease due to the denaturing of the enzyme. Very low temperatures result in very low functionality. Mid-range temperatures result in maximum functionality. Very high temperatures result in very low functionality. As a result, the graph will be shaped like a bell-curve.
Enzymes are proteins that catalyze the biological reactions in the body. Every enzyme has a unique set of conditions in which it functions optimally. The function of an enzyme can be plotted on a graph, with the functionality of the enzyme on the y-axis, and the factor being manipulated on the x-axis. What will be the shape of a graph with enzyme reaction rate on the y-axis, and substrate concentration on the x-axis? Possible Answers: The graph will be exponentially increasing curve The graph will be a line with a positive slope The graph will climb quickly, then will start to even off before reaching a plateau The graph will be a bell shaped curve Correct answer: The graph will climb quickly, then will start to even off before reaching a plateau Explanation: As substrate concentration is increased, the reaction rate will increase accordingly; however, let's think about the extreme case where there is an extremely large amount of substrate. Eventually, every binding site of every molecule of enzyme will be filled. Substrate molecules will have to wait in order to be catalyzed by the enzyme. When this happens, we say that the enzyme is saturated. At this point, the graph will begin to level off and look like a horizontal line. In summary, the graph will rise quickly in the beginning, but will eventually level off as substrate concentration becomes excessive compared to the available enzyme in solution. What would you predict would happen to pancreatic enzymes if they were introduced to the stomach? Possible Answers: Their function would decrease due to decreased pH Their function would decrease due to increased pH Their function would increase due to decreased proton concentration Their function would increase due to decreased pH Correct answer: Their function would decrease due to decreased pH Explanation: The efficiency of an enzyme is dependent on the pH (as well as other features) of the environment in which it acts. The pancreatic digestive enzymes are typically secreted into the small intestine, which has a pH of about 6. As a result, the acidic pH of the stomach (about 2) would significantly reduce the efficiency of the pancreatic enzymes. Remember that, though the stomach contents is highly acidic, it is neutralized in the duodenum before continuing through the small intestine, thus allowing these enzymes to function. Which term is used to refer to an inactive enzyme precursor? Possible Answers: Holoenzyme Apoenzyme Inhibitor Zymogen Null enzyme Explanation: Zymogen is the correct term for the inactive precursor of an enzyme. Zymogens are cleaved by other enzymes in order to become active. The zymogen form can help prevent improper action of the enzyme in different regions of the body. For example, trypsinogen is a zymogen released from the pancreas. It is transported to the small intestine before become active trypsin to prevent the trypsin from accidentally digesting and damaging the pancreatic cells. Apoenzymes refer to enzymes without cofactors, while holoenzymes are enzymes bound to their cofactors. Inhibitors bind to enzymes to block their activity. Which of the following changes could lead to loss of enzymatic function? Possible Answers: Increase in pH of the reaction Change in overall free energy of the reaction Decrease in activation energy of the reaction Increase in enzyme concentration Change in overall enthalpy of the reaction Correct answer: Increase in pH of the reaction Explanation: Enzymes are pH and temperature sensitive., and only function in optimal ranges of these conditions. Certain enzymes will only function in acidic environments, while others require basic conditions. The overall free energy and enthalpy of the reaction, activation energy, and enzyme concentration do not have a bearing on enzymatic activity. Duchenne Muscular Dystrophy is an X-linked recessive genetic disorder, resulting in the loss of the dystrophin protein. In healthy muscle, dystrophin localizes to the sarcolemma and helps anchor the muscle fiber to the basal lamina. The loss of this protein results in progressive muscle weakness, and eventually death. In the muscle fibers, the effects of the disease can be exacerbated by auto-immune interference. Weakness of the sarcolemma leads to damage and tears in the membrane. The body’s immune system recognizes the damage and attempts to repair it; however, since the damage exists as a chronic condition, leukocytes begin to present the damaged protein fragments as antigens, stimulating a targeted attack on the damaged parts of the muscle fiber. The attack causes inflammation, fibrosis, and necrosis, further weakening the muscle. Studies have shown that despite the severe pathology of the muscle fibers, the innervation of the muscle is unaffected. Which of the following would best describe the dystrophin protein? Possible Answers: Signaling protein Chemical receptor Ion channel Transmembrane protein Fibrous protein Correct answer: Transmembrane protein Explanation: The passage tells us that "dystrophin localizes to the sarcolemma," so we know it is located at the membrane of the muscle fiber. We also know that its role is to structurally link the muscle fiber and the basal lamina. We can eliminate the choices for ion channel, signaling protein, and chemical receptor based on what we know about dystrophin's function. We are left with either fibrous protein or transmembrane protein. Though fibrous proteins also have structural roles, transmembrane protein is the best choice because we know that dystrophin is linking the muscle fiber to another structure, meaning that it must span the membrane. Which of the following is FALSE concerning enzymes? Possible Answers: Enzymes increase both the forward rate and reverse rate of a reaction Enzymes reduce reaction activation energy Enzymes increase the amount of product created in a reaction Substrates must bind the enzyme's active site in order to initiate its effects Enzymes are not destroyed in a reaction and can be used in the same reaction countless times Correct answer: Enzymes increase the amount of product created in a reaction Explanation: Enzymes will increase the rate of a chemical reaction, but will not alter the equilibrium of a reaction. As a result, the amount of product is not affected by enzymes. The same amount of product will be made; it will just be made at a faster rate. The end product of an enzymatic reaction inhibits formation of product in an earlier step. This type of enzymatic regulation is known as __________. Possible Answers: metabolic pathway loop feedback inhibition enzyme-substrate complex negative regulation allosteric regulation Correct answer: feedback inhibition Explanation: Feedback inhibition is a type of regulation in which an enzyme product blocks an earlier part of a metabolic reaction. This allows cells to regulate resources by signaling when enough product is made. All MCAT Biology ResourcesWhich statements are correct for all enzymes?The correct option is C. All of the following statements are correct for enzymes, except.. Assertion(A): Hormones are similar to enzymes in their action and chemical nature. ... . A:-All enzymes are proteins.. Which of the following statements is true about all enzymes?The true statement is C) All enzymes are not proteins
They facilitate the reaction but does not undergo any change within themselves.
Which three are correct statements about enzymes?(1) Enzymes may change shape when they bind substrates; (2) Enzymes provide no energy for the reaction, except collision energy; (3) Enzymes may release substrates.
Which one of the following statement about enzymes is incorrect?Enzymes are very specific for a particular reaction and substrate.
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