All Flashcards
What are the differences between the 'lock and key' model and the 'induced fit' model of enzyme action?
Lock and Key: Enzyme active site is rigid and perfectly matches the substrate. | Induced Fit: Enzyme active site is flexible and changes shape to better fit the substrate.
What are the differences between the active site and allosteric site?
Active Site: Where substrate binds and reaction occurs. | Allosteric Site: Where a regulator molecule binds, affecting enzyme activity.
What are the four levels of protein structure?
Primary: amino acid sequence; Secondary: alpha-helices and beta-sheets; Tertiary: overall 3D shape; Quaternary: arrangement of multiple polypeptide subunits.
Briefly describe the process of enzyme-substrate interaction.
Substrate binds to the enzyme's active site, forming an enzyme-substrate complex. The enzyme then catalyzes the reaction, converting the substrate into product(s).
Describe the induced fit model process.
Enzyme's active site is flexible. Substrate binds. Enzyme changes shape for tighter fit. Transition state forms more efficiently.
What is the effect of increasing substrate concentration on enzyme activity (assuming enzyme concentration is constant)?
Initially, reaction rate increases; but eventually plateaus when all enzyme active sites are saturated.
What is the effect of a significant increase in temperature on enzyme structure and function?
Enzyme denatures, losing its 3D shape and active site functionality, thus reducing or eliminating its catalytic activity.
What is the effect of a non-optimal pH on enzyme activity?
Disrupts the hydrogen bonds and ionic interactions that maintain the enzyme's 3D structure, leading to reduced activity or denaturation.