Enzymes Flashcards
Difference between lock & key model and Induced fit model:
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo there is a conformational change / change inn shape when binding a substrate, to improve the fit.
Similarity between lock & key model and Induced fit model:
Both models describe an enzyme-catalyzed reaction. They explain substrate binding to the active site of an enzyme.
Lipase
Breaks down lipids
Catalase
Chemical Indicator
Changes color based on PH (alkaline: pink, acidic: colorless)
Catabolic
Larger molecules are separated to form smaller molecules.
Hydrolysis
Hydrolysis is any chemical reaction in which a molecule of water breaks one or more chemical bonds.
Condensation
A reaction in which two or more molecules combine to form a larger molecule.
Anabolic
A reaction that synthesizes larger molecules from smaller constituent parts, using ATP as the energy source for these reactions.
Enzyme + Substrate –> Enzyme substrate complex
–> Enzyme + Product - enzyme is not consumed nor changed in the process
Factors affecting rate of reaction
Collision Theory Criteria
1) Reactants (including enzymes and substrates) collides (active site - enzyme catalized)
2) Collision should happen in the correct orientation specifically the substrate should bind on active site of the enzyme.
3) Minimum energy requirement for the enzyme reaction must be met.
Endothermic Reaction
Energy of products is higher than energy of the reactions because the products absorb the energy.
Exothermic Reaction
Energy of reactants is higher than energy of the products.
Reaction Rate - Amount of Product
Overtime the amount of product increases and then plateaus because there is a decrease no more reactants left to create the products.
Reaction Rate - Amount of Product
Overtime the amount of reactant decreases and then plateaus because the reactants are all used to create the products.
Slope of the reaction rate
As the reaction progresses, the concentration of product increases and then plateaus. This leads to lower frequency of collision with the correct orientation and sufficient energy. Thus, rate increases as reactions progress - lowest at the beginning and highest at the end.
Slope of the reaction - reactants
As the reaction progresses, the concentration of reactants decreases. This leads to lower frequency of collision with the correct orientation and sufficient energy. Thus, rate decreases as reactions progress - highest at the beginning and lowest at the end.
Rate
Change in amount of reactants over time (/[reactant]/time) resulting in a negative value as the reactants are consumed in the reaction. Change in amount of products over time (/[product]/time).
Temperature and its effects on the rate of reactions
Changing temperature changes the average kinetic energy of the particles hence changing the speed of the particles changes the frequency of collisions hence changes the probability of successful collisions where the substrate collides to the active site of the enzymes which effects the reaction rate. If the temperature increases the rate of reactions increases because the reaction rate is higher.
Denaturing of enzymes
The enzyme changes in shape because the links of reactant’s bond are broken when the optimal temperature is not met hence changing the shape of the enzyme which means the change in shape of the active site of the enzyme. This results in the decline in the rate of reaction because the substrate doesn’t to fit in the active site which changed in shape.
Concentration and its effects on the rate of reactants.
Changing concentration, changes the number of particles within a specified space, changing the frequency of collisions. This also results in the change in the probability of successful collisions affecting the reaction rate.
Concentration example
The rate of reaction plateaus over time because the active sites of enzymes present are occupied hence not every substrate is able to react to create the product - check
[s]
Brackets signify the amount or concentration.
