All Flashcards
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 an enzyme?
A biological catalyst that speeds up chemical reactions in living organisms.
What is a catalyst?
A substance that speeds up a chemical reaction without being consumed in the reaction.
What is the active site of an enzyme?
The specific region of an enzyme where the substrate binds and catalysis occurs.
What is a substrate?
The reactant on which an enzyme acts to catalyze a chemical reaction.
What is induced fit?
A model describing how an enzyme changes shape upon substrate binding to create a better fit, enhancing catalysis.
What is enzyme specificity?
The ability of an enzyme to catalyze only certain reactions due to the unique shape of its active site.
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.