2.4.2 Enzyme kinetics

• Vmax is the maximum reaction rate when the enzyme is fully saturated with substrate.


  True
• Order the effect of increasing substrate concentration on enzyme kinetics.

  1️⃣ Initial increase in reaction rate

  2️⃣ Saturation of enzyme active sites

  3️⃣ Reaction rate plateaus at Vmax
• The Michaelis-Menten equation describes the rate of an enzyme-catalyzed reaction.


  True
• Km is the substrate concentration at which the reaction rate is half of Vmax
• What does a lower Km value indicate about enzyme-substrate affinity?

  Higher affinity
• What is enzyme kinetics the study of?

  Rate of enzyme-catalyzed reactions
• Factors affecting enzyme kinetics include substrate concentration, enzyme concentration, temperature, and pH
• What happens to enzyme kinetics when temperature increases beyond the optimal range?

  Reaction rate decreases
• What does Vmax represent in the Michaelis-Menten equation?

  Maximum reaction rate
• Match the enzyme kinetic parameter with its definition:

  Vmax ↔️ Maximum reaction rate

  Km ↔️ Substrate concentration at half Vmax
• What are Vmax and Km critical parameters in enzyme kinetics used to characterize?

  Enzyme behavior
• Vmax represents the maximum reaction rate when the enzyme is saturated with substrate.


  True
• Lower Km values indicate higher enzyme affinity for the substrate
• Increasing substrate concentration increases reaction rate up to a maximum
• Match the parameter with its definition and significance:

  Vmax ↔️ Maximum reaction rate, catalytic capacity

  Km ↔️ Substrate concentration at half Vmax, enzyme affinity
• Glucokinase requires higher substrate concentrations to achieve optimal activity due to its high Km value.


  True
• Lower Km values indicate a strong enzyme-substrate interaction, leading to higher affinity and specificity.

  True
• The Michaelis-Menten equation is given by $v =$ \frac{V_{\max}[S]}{K_{m} + [S]}, where Km is the substrate concentration at half Vmax.
• Enzymes work best at body temperature (around 37°C).


  True
• The Lineweaver-Burk plot is a graphical representation of the Michaelis-Menten equation.
• Steps to construct a Lineweaver-Burk plot

  1️⃣ Plot the reciprocal of the reaction rate (1/v) on the y-axis

  2️⃣ Plot the reciprocal of the substrate concentration (1/[S]) on the x-axis
• The y-intercept of a Lineweaver-Burk plot represents 1/Vmax.
• Match the inhibition type with its mechanism:

  Competitive ↔️ Inhibitor binds to the active site

  Non-competitive ↔️ Inhibitor binds to a site other than the active site

  Uncompetitive ↔️ Inhibitor binds to the enzyme-substrate complex
• Uncompetitive inhibition decreases both Km and Vmax.
• Understanding enzyme kinetics is crucial for optimizing enzyme-catalyzed processes in biological and industrial applications.


  True
• The Michaelis-Menten equation is $v =$ \frac{V_{\max}[S]}{K_{m} + [S]}, where Vmax is the maximum reaction rate.
• What is the optimal pH range for enzyme activity?

  Depends on the enzyme
• The Michaelis-Menten equation describes the rate of an enzyme-catalyzed reaction in relation to substrate concentration.
• What is the Michaelis-Menten equation?

  $v =$ \frac{V_{\max}[S]}{K_{m} + [S]}
• Match the component of the Michaelis-Menten equation with its definition:

  v ↔️ Reaction rate

  Vmax ↔️ Maximum reaction rate

  [S] ↔️ Substrate concentration

  Km ↔️ Michaelis constant
• The Michaelis constant, Km, indicates the enzyme's affinity for the substrate.
• Match the Km value with its corresponding enzyme affinity and efficiency:

  Lower Km (e.g., < 1 mM) ↔️ High affinity and efficiency

  Higher Km (e.g., > 10 mM) ↔️ Low affinity and efficiency
• Lower Km values indicate a strong enzyme-substrate interaction.


  True
• Km is measured in units of moles per liter
• Order the factors affecting enzyme kinetics based on their effect on reaction rate:

  1️⃣ Substrate concentration

  2️⃣ Enzyme concentration

  3️⃣ Temperature

  4️⃣ pH
• Enzymes have an optimal pH range where reaction rate is maximized.


  True
• Match the component of the Michaelis-Menten equation with its definition:

  v ↔️ Reaction rate

  Vmax ↔️ Maximum reaction rate

  [S] ↔️ Substrate concentration

  Km ↔️ Michaelis constant
• The Michaelis-Menten equation describes how the reaction rate changes with substrate concentration.


  True
• What does Vmax represent in the Michaelis-Menten equation?

  Maximum reaction rate
• Km indicates the enzyme's affinity for the substrate