How enzymes work Flashcards
activation energy
the energy needed for a chemical reaction to get started
substrate
the molecule or molecules on which an enzyme acts
lock-and-key hypothesis
a model that explains enzyme actions by an active site in the protein structure that has a very specific shape; the enzyme and substrate slot together to form a complex in the same way as a key fits a lock
active site
the area of an enzyme that has a specific shape into which the substrate(s) of a reaction fit
induced-fit hypothesis
a modified version of the lock-and-key model of enzyme action where the active site is considered to have a more flexible shape; after the substrate enters the active site, the shape of that site changes around it to form the active complex; after the complex, the enzyme returns to its inactive relaxed form
molecular activity(turnover number)
the number of substrate molecules transformed per minute by a single enzyme molecule
temperature coefficient Q10
the measure of the effect of temperature on the rate of a reaction
denaturation
the loss of the 3D shape of a protein (e.g caused by changes in temperature or pH)
initial rate of reaction
the measure taken to compare the rates of enzyme-controlled reactions under different conditions
