Enzymes Flashcards
State the effect of an enzyme on a reaction in terms of energy. What is changed and unchanged?
The activation energy with an enzyme is changed and becomes lower. The decrease/increase of energy between the reactants and progress is unchanged.
Wild carrrrrd! Make sure you can tell the difference between an exothermic reaction graph and an endothermic reaction graph.
Define a catabolic and anabolic reaction and which is endothermic/exothermic.
A catabolic reaction involves degradation; the substrate is broken down into smaller products. It is an exothermic reaction.
An anabolic reaction involves synthesis. The substrates are combined to produce a larger product. It is an endothermic reaction.
What are the two enzyme models and what do they entail? Which is more generally accepted?
Lock-and-key model: the active site of an enzyme precisely fits a specific substrate.
Induced-fit model: the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
The induced-fit model is more accepted.
Easy one nom nom nom! What is the active site and what is a substrate?
Active site: region in enzyme that the substrate binds to
Substrate: reactant that an enzyme acts on
Explain the induced fit model in depth.
The induced fit of a substrate brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction. During the binding, the active site is not completely rigid; it may undergo a conformational change in shape to better fit the substrate. This change may also increase the substrate’s reactivity and be necessary for the enzyme’s catalytic activity.
