Kinetics & Water

Which of the following best describes the difference between ΔG (overall free energy change) and ΔG≠ (free energy of activation)?

• ΔG determines the speed of a reaction, while ΔG≠ determines whether the reaction is spontaneous.

• ΔG indicates thermodynamic favorability of a reaction, while ΔG≠ represents the energy barrier that must be overcome for the reaction to proceed.

• ΔG≠ measures the energy released in a reaction, while ΔG measures the energy needed to start the reaction.

• ΔG relates to equilibrium, while ΔG≠ indicates thermodynamic favorability of a reaction.

The specificity of an enzyme is controlled by __________.

• The concentration of the enzyme

• The pH of the environment

• The temperature of the reaction

• The structure of the enzyme

In enzyme kinetics, what does the term "steady state" refer to?

• The condition where the enzyme and substrate concentrations remain constant throughout the reaction.

• The condition where the concentration of the enzyme-substrate complex remains constant

• The point at which all substrate has been converted to product

• The condition where the substrate is completely consumed, and the reaction comes to a stop

Why does the enzyme kinetics graph (reaction velocity vs. substrate concentration) level off, forming a hyperbolic shape?

• The enzyme becomes denatured at high substrate concentrations.

• The enzyme is fully saturated with substrate, and all active sites are occupied.

• The substrate concentration decreases, reducing the reaction rate.

• The product inhibits the enzyme, stopping the reaction.

In enzyme kinetics, when substrate concentration is low, the equation for the reaction rate is ________, and when substrate concentration is high, the equation for the reaction rate is ________.

• Zero-order kinetics; first-order kinetics

• First-order kinetics; second order kinetics

• Second-order kinetics; first-order kinetics

• First-order kinetics; zero-order kinetics

Tags

NGSS.HS-PS1-5

Which type of inhibitor never effects the Km?

• Competitive inhibitor

• Mixed inhibitor

• Uncompetitive inhibitor

• Noncompetitive inhibitor

In enzyme kinetics, which of the following best describes an ordered single displacement reaction mechanism?

• The enzyme binds two substrates simultaneously, and the products are released before the second substrate binds.

• One substrate binds to the enzyme, the second substrate binds and products are released in order of substrate binding.

• The enzyme binds to the substrates in a random order, and both products are released together.

• The enzyme binds to one substrate, forming an intermediate that is converted to the product before the second substrate binds.

Tags

NGSS.HS-PS1-2

Which of the following best describes a double displacement (ping pong) mechanism in enzyme kinetics?

• The enzyme binds two substrates at once, and both products are released together after the reaction.

• One substrate binds to the enzyme, and the product is released before the second substrate binds, with no enzyme modification in between.

• The enzyme forms a covalent bond with one substrate before releasing the first product and then binding the second substrate.

• Both substrates bind to the enzyme simultaneously, and no intermediate is formed during the reaction.

What property of water makes it an excellent solvent for ionic solutions?

• Its polarity

• Its high heat capacity.

• Its ability to form covalent bonds.

• Its low density in the solid state

Tags

NGSS.HS-ESS2-5

What happens to the entropy of the system when a hydrophobic compound is introduced into water?

• Entropy increases because water molecules become more disordered around the hydrophobic compound.

• Entropy fluctuates depending on the size of the hydrophobic compound.

• Entropy remains unchanged as hydrophobic compounds do not affect water structure

• Entropy decreases because water molecules become more ordered around the hydrophobic compound