Enzymes and Catalysts (Unit 1) Flashcards
How do enzymes function?
Enzymes are protein catalysts that speed up chemical reactions by lowering activation energy, exhibiting substrate specificity, and forming an enzyme-substrate complex through induced fit at the active site.
How does enzyme concentration affect enzyme activity?
Enzyme concentration affects enzyme activity linearly, meaning more enzyme concentration typically results in increased activity, as long as there is substrate available.
How does substrate concentration affect enzyme activity?
Initially, increasing substrate concentration increases enzyme activity. However, this forms a spike, eventually plateauing when enzymes are saturated with substrate.
How does temperature affect enzyme activity?
Increased temperature generally allows for more enzyme activity, up to a point where the enzyme may denature and activity decreases.
How does pH affect enzyme activity?
Each enzyme has an optimal pH range in which it operates most efficiently. The activity typically follows a bell curve relative to pH changes.
What is a competitive inhibitor and how does it affect enzyme activity?
A competitive inhibitor resembles the substrate and competes for binding at the enzyme’s active site. This can prevent the actual substrate from binding and decrease enzyme activity.
What is a noncompetitive inhibitor and how does it affect enzyme activity?
A noncompetitive inhibitor binds to a site other than the active site on the enzyme. This binding causes a conformational change in the enzyme, preventing the substrate from binding effectively at the active site.
What is allosteric regulation?
Allosteric regulation involves the binding of an effector molecule at a site other than the enzyme’s active site, leading to a conformational change that can either activate or inhibit enzyme activity.
What are allosteric activators and inhibitors?
Allosteric activators stabilize the active form of an enzyme, enhancing its activity. Allosteric inhibitors stabilize the inactive form of the enzyme, reducing its activity. These are considered forms of non-competitive inhibition.
What is feedback inhibition?
Regulation of a pathway by one of the products of this pathway
Prevents cellular resources from being wasted in synthesis of molecules at intermediate steps in this pathway. Allosteric regulators control chemical activity in the cell
What is an enzyme and what is its function?
Biological catalyst (usually a protein) speeds up a chemical reaction without being consumed
Lowers the activation barrier to speed up a reaction
