1) An enzyme that catalyzes the transformation of one substrate is characterized by the following specificity: a)absolute: b) relative; c) stereospecificity; d)allosteric: e) group. 2) Most food and microbial enzymes are destroyed at {}^circ C a) 15 b) 25 c) 37 d) 80 3) Regulation of enzyme activity cannot be carried out by: a) covalent chemical modification; b) formation of a substrate-substrate complex; c) allosteric regulation; d) partial proteolysis. 4) The division of enzymes into classes is based on: a) substrate structure b) structure of coenzymes c) structure of reaction products d) type of catalyzed reaction 5) The Michaelis-Menten equation. If for Enzyme "A" Vmax equals to 100mu mol/mL sec and Km equals to 2 mM, what is the velocity of the reaction when substrate "B"concentration equals to 20 mM?

1) An enzyme that catalyzes the transformation of one substrate is characterized by the following specificity:<br />a) absolute: This is the correct answer. Absolute specificity refers to an enzyme that catalyzes the transformation of only one substrate.<br /><br />2) Most food and microbial enzymes are destroyed at ${}^{\circ }C$<br />c) 37: This is the correct answer. Most food and microbial enzymes are destroyed at 37°C, which is the optimal temperature for the growth of many microorganisms.<br /><br />3) Regulation of enzyme activity cannot be carried out by:<br />b) formation of a substrate-substrate complex: This is the correct answer. The formation of a substrate-substrate complex is not a method of regulating enzyme activity.<br /><br />4) The division of enzymes into classes is based on:<br />d) type of catalyzed reaction: This is the correct answer. Enzymes are divided into classes based on the type of reaction they catalyze.<br /><br />5) The Michaelis-Menten equation. If for Enzyme "A" Vmax equals to $100\mu mol/mL$ sec and Km equals to 2 mM, what is the velocity of the reaction when substrate "B" concentration equals to 20 mM?<br />To solve this question, we can use the Michaelis-Menten equation:<br /><br />V = (Vmax \* [S]) / (Km + [S])<br /><br />where V is the velocity of the reaction, Vmax is the maximum velocity, [S] is the substrate concentration, and Km is the Michaelis constant.<br /><br />Given that Vmax = 100 μmol/mL sec and Km = 2 mM, we can substitute these values into the equation:<br /><br />V = (100 μmol/mL sec \* 20 mM) / (2 mM + 20 mM)<br /><br />V = 2000 μmol/mL sec / 22 mM<br /><br />V ≈ 90.91 μmol/mL sec<br /><br />Therefore, the velocity of the reaction when the substrate "B" concentration equals to 20 mM is approximately 90.91 μmol/mL sec.