19. Enzymes

Which of the following could be the possible name of enzyme that involves the transference of a phosphate group between substrates?

Which of the following enzyme name and function is incorrectly matched?

Which of the following statements is true of ethanal reductase?

Identify the class and subclass of an enzyme that catalyzes the following reaction.

Which of the following catalyzes the given reaction involving a triglyceride?

Describe the reactions that you would expect these enzymes to catalyze.

b. Aspartate transaminase

Name the enzyme whose substrate is

a. Urea

Answer questions (a)–(e) concerning the following reaction:

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b. Since hydrogens are removed, the enzyme belongs to what subclass of the enzyme class from part (a)?

Answer questions (a)–(e) concerning the following reaction:

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c. What is the substrate for the reaction as written?

"Answer questions (a)–(e) concerning the following reaction:

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d. What is the product for the reaction as written?

Name an enzyme that acts on each molecule.

c. DNA

What general kinds of reactions do the following types of enzymes catalyze?

b. Decarboxylases

Name an enzyme that acts on each molecule.

a. Lactose

What general kinds of reactions do the following types of enzymes catalyze?

c. Lipases

Name an enzyme that acts on each molecule.

a. Amylose

Name an enzyme that acts on each molecule.

c. RNA

What classes of enzymes would you expect to catalyze the following reactions?

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What kind of reaction does each of these enzymes catalyze?

b. A transmethylase

What kind of reaction does each of these enzymes catalyze?

c. A reductase

Alcohol dehydrogenase (ADH) catalyzes the following reaction. To what class of enzymes does ADH belong? <IMAGE>

Which of the following reactions can be catalyzed by a decarboxylase?

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Identify and describe the chemical change in the lyase-catalyzed reaction in Table 19.4 that involves fumarate and malate. Identify the substrate(s) and product(s). <IMAGE>

Answer questions (a)–(e) concerning the following reaction:

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a. The enzyme involved in this reaction belongs to what class of enzymes?

The meat tenderizer used in cooking is primarily papain, a protease enzyme isolated from the fruit of the papaya tree. Why do you suppose papain is so effective at tenderizing meat?

The reaction that follows is catalyzed by isocitrate dehydrogenase and occurs in two steps, the first of which (step A) is formation of an unstable intermediates (shown in brackets).

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d. To what class of enzymes does isocitrate dehydrogenase, the enzyme that catalyzes this reaction, belong?

Serotonin is a monoamine neurotransmitter. It is formed in the body from the amino acid tryptophan (Figure 28.6, p. 836). What class of enzyme catalyzes each of the two steps that convert tryptophan to serotonin?

What is the reactant for each of the following enzymes?

a. galactase

What is the name of the class of enzymes that would catalyze each of the following reactions?

c. converting glucose (C₆H₁₂O₆) to fructose (C₆H₁₂O₆).

What is the name of the class of enzymes that would catalyze each of the following reactions?

a. addition of water to a double bond

Ethylene glycol (HO—CH₂—CH₂—OH) is a major component of antifreeze. If ingested, it is first converted to HOOC—CHO (oxoethanoic acid) and then to HOOC—COOH (oxalic acid), which is toxic. (16.4, 16.5).

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a. What class of enzyme catalyzes the reactions described?

Adults who are lactose intolerant cannot break down the disaccharide in milk products. To help digest dairy food, a product known as Lactaid can be added to milk and the milk then refrigerated for 24 hours. (16.4, 16.5)

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a. What enzyme is present in Lactaid, and what is the major class of this enzyme?

 Indicate whether each of the following would be a substrate (S) or an enzyme (E): (16.4)

a. glucose

Give the substrate of each of the following enzymes: (16.4)

a. urease

Give the substrate of each of the following enzymes: (16.4)

a. maltase

Does each of the following statements describe a simple enzyme (no cofactor or coenzyme necessary), an enzyme that requires a cofactor, or an enzyme that requires a coenzyme?

b. consists of one polypeptide chain in its active form

Does each of the following statements describe a simple enzyme (no cofactor or coenzyme necessary), an enzyme that requires a cofactor, or an enzyme that requires a coenzyme?

c. contains vitamin B₆ in its active site