Enzyme Kinetics (Activation Energy and Gibb's Free Energy)

The video tutorial covers the kinetics and thermodynamics of enzyme reactions, focusing on the concepts of activation energy, free energy changes, and the role of enzymes. It explains how activation energy affects reaction rates and how enzymes lower this energy to speed up reactions. The tutorial also distinguishes between kinetic and thermodynamic favorability, emphasizing that these are independent concepts. Additionally, it clarifies the difference between exergonic and endergonic reactions and the implications of Delta G values on reaction spontaneity.

What is the primary focus of kinetics in enzyme reactions?

• The stability of the transition state

• The rate at which a reaction occurs

• The equilibrium constant of the reaction

• The energy difference between reactants and products

What does the transition state in a reaction represent?

• The initial reactants before the reaction starts

• An unstable intermediate state

• The point of maximum stability

• The final product of the reaction

What does a negative Delta G indicate about a reaction?

• The reaction is non-spontaneous

• The reaction is endergonic

• The reaction requires a net input of energy

• The reaction releases energy

Which of the following is true about exergonic reactions?

• They release energy

• They are always irreversible

• They have a positive Delta G

• They require a net input of energy

How can you determine if a reaction is more thermodynamically favorable?

• By the speed of the reaction

• By the concentration of reactants

• By comparing the activation energies

• By the magnitude of the negative Delta G

What does a positive Delta G signify about a reaction?

• The reaction is spontaneous

• The reaction is faster than one with a negative Delta G

• The reaction is exergonic

• The reaction requires a net input of energy

Which statement is true about the relationship between kinetics and thermodynamics?

• Kinetics and thermodynamics are independent of each other

• Thermodynamics determines the speed of a reaction

• Kinetics determines the thermodynamic favorability of a reaction

• Thermodynamics affects the activation energy

What is the role of enzymes in chemical reactions?

• They increase the free energy of the products

• They increase the energy of the reactants

• They change the equilibrium of the reaction

• They lower the activation energy

How do enzymes affect the rate of a reaction?

• By increasing the free energy of the products

• By increasing the free energy of the reactants

• By lowering the activation energy

• By changing the equilibrium constant

What is the rate-determining step in an enzyme-catalyzed reaction?

• The step with the highest activation energy

• The last step of the reaction

• The first step of the reaction

• The step with the lowest activation energy