Question

1. a chemical reaction is a process by which atoms or molecules in a substance are; a. dissolved in other substances b. ionized by the loss of protons c. mixed together with atoms in other substances d. rearranged into different substances 31. the substances that enter or start a reaction are called: a. ingredients c. reactants b. products d. solvents 32. jennas favorite breakfast food, papaya, contains significant amounts of the enzyme papain, a protease. based on your knowledge of the names of enzymes, what substances does papain help digest? a. carbohydrates c. nucleic acids b. fatty acids d. proteins 33. all of the following determine how effectively an enzyme can react with a substrate except: a. optimal ph b. amount of substrate produced c. concentration of enzymes d. optimal temperature 34. in this series of metabolic reactions, compound r is converted into compound a, and enzyme x then catalyzes the conversion of compound a into compounds b and d. compound b is converted to compound c. r→a→x→b→c assume that compound c inhibits enzyme x and that compound c is not consumed in a subsequent reaction. as the concentration of compound c increases, the rate of production of which compound is least likely to decrease? a. a b. b c. c d. d 35. does the following graph indicate an endergonic/endothermic or an exergonic/exothermic reaction? a. endergonic b. exergonic

Explanation:

• Question 30: A chemical reaction involves the rearrangement of atoms or molecules in substances to form different substances. Dissolving is a physical - change, ionization by loss of protons is a specific type of reaction step, and mixing is a physical process.
• Question 31: Reactants are the substances that enter or start a reaction. Ingredients are more general in a non - chemical context, products are the results of a reaction, and solvents are substances in which other substances dissolve.
• Question 32: Proteases are enzymes that break down proteins. Papain, being a protease, helps digest proteins.
• Question 33: The amount of substrate produced is a result of the reaction, not a factor that determines how effectively an enzyme can react with a substrate. Optimal pH, enzyme concentration, and optimal temperature all affect enzyme - substrate reactions.
• Question 34: Compound C inhibits Enzyme X. As the concentration of C increases, it will inhibit Enzyme X more, reducing the conversion of A to B and D. Compound A is the product of the first step and is not directly affected by the inhibition of Enzyme X by C.
• Question 35: In an exergonic reaction, energy is released. Without seeing the graph, but conceptually, exergonic reactions have a negative free - energy change. In an endergonic reaction, energy is absorbed.

Answer:

1. D. rearranged into different substances
2. C. reactants
3. D. proteins
4. B. Amount of substrate produced
5. A. A
6. b. exergonic