Which of the following statements is true for all exergonic reactions? The products have more total energy than the reactants. false The reaction proceeds with a net release of free energy. true The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. false A net input of energy from the surroundings is required for the reactions to proceed. false Single A chemical reaction that has a positive ΔG is best described as ________.  endergonic true enthalpic false spontaneous false exergonic false Single Which of the following statements describes the role of ATP in the cell? Hydrolysis of ATP provides free energy for exergonic reactions. false ATP provides energy coupling between exergonic and endergonic reactions. true Hydrolysis of the terminal phosphate group stores free energy for cellular work. false The terminal phosphate bond is stronger than other covalent bonds in biomolecules. false Single Which molecule is most similar to the structure of ATP? a pentose sugar false a DNA nucleotide false an RNA nucleotide true an amino acid with three phosphate groups false Single When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell? It is secreted as waste. false It is used only to regenerate more ATP. false It may be used to form a phosphorylated intermediate. true It enters the nucleus to be incorporated in a nucleotide. false Single Which of the following statements about enzyme function is true? Enzyme function is generally increased if the three-dimensional structure or conformation of an enzyme is altered. false Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. false Enzymes increase the rate of chemical reactions by lowering activation energy barriers. true Enzymes increase the rate of chemical reactions by providing activation energy to the substrate. false Single What is the barrier that must be overcome before products are formed in a spontaneous reaction? enzyme false activation energy true transition point false free energy false Single What do you call the part of the enzyme that catalyzes the reaction? reactant false substrate false active site true cofactor false Single The following affect the activity of enzymes, EXCEPT: cofactors false pH false temperature false molecular weight true Single Which of the following graphs most likely describes the effect of pH on the function of the enzyme catalase in human cells? Note: The x-axis is pH, and the y-axis is enzyme activity. The graph has a positive slope false The graph has a negative slope false The graph is parabolic true The graph is horizontal. false Single