AP Bio 3.3 Flashcards
What is the 3D shape of an enzyme called?
Tertiary structure, (or the conformational shape)
What is denaturation?
Changes in the conformational shape of an enzyme
What can lead to denaturation?
Changes in pH, and temperature.
Is enzyme denaturation reversible?
Typically, no.
It’s ability is usually lost or severly decreased
In some cases, is enzyme denaturation reversible?
Yas
What is meant by the optimum temperature?
The ideal temperature for enzyme activity (fastest catalyzation)
What happens when optimum ranges aren’t maintained
Reaction rates change
What happens when temperatures exceed the optimum temperature for an enzyme?
An initial increase rate of reaction, molecular movement, and enzyme substrate collisions. Temperatures that are too high lead to denaturation.
What happens when temperatures are less than the optimum temperature for an enzyme?
There is a decrease in the rate of reactions, but it does not lead to the denaturation of the enzyme or change in the enzymes structure
What does pH measure?
It measures the concentration of hydrogen ions in a solution
How is pH measured (mathematical wise)?
It is measured on a logartithmic scale
Small changes in pH equate to large changes in hydrogen concentration
pH 6 has 10x more hydrogen ions that pH 7
What is meant by optimum pH?
it’s the ideal pH range for an enzyme to facilitate reactions (fastest reactions).
What does a change in optimum pH level cause in an enzyme?
It causes either the slowing down or stopping of enzyme activity, as well as denaturation. Both high pH and low pH can lead to denaturation (if it’s outside of the optimum range)
How can pH effect the structure of an enzyme?
The hydrogen ion concentration can effect the hydrogen bond interactions in the enzyme
What does an increase in substrate do (when considering enzyme reactions)?
It generally means more reactions and more opportunity to collide with the enzyme
What is something that will happen at some point in the reactions?
Substrate saturation
What will happen to the saturation levels if the reaction rate is maintained?
The saturation levels are maintained
What does an increased amount of products result in?
A decreased chance of new reactions occuring/the collision of substrates to the enzyme, slowing the reaction rate
What is something that slows down the reaction rate of an enzyme?
The increased level of products in its surrounding environment
Can changes in enzyme concentration change the reaction rate?
Yup
What happens if there are more enzymes?
Faster reaction rate
More opportunities for the substrate to collide with the active site
What happens if there are fewer enzymes?
Slower reaction rate
Fewer opportunities for the substrate to collide with the active site
What are competitive inhibitors?
They are molecules that can bind reversibly or irreversibly to the active site of the enzyme, competing with the normal substrate for the enzymes active site
What happens if competitive inhibitor concentrations are higher than the subsrate concentrations?
The reactions are slowed down
What happens if competitive inhibitor concentrations are considerably lower than the subsrate concentrations?
The reactions can proceed normally
What happens if an inhibitor binds irreversibly to the active site of an enzyme?
It’s activity will come to an end
What happens when an inhibtor binds reversibly to the active site of an enzyme?
The enzyme can regain it’s ability to facilitate reactions once the inhibitor detaches
What are the sites that can be found on an enzyme?
The active site, into which the subtrate binds in order for a reaction to be facilitated, along with the competitive inhibitors (to inhibit the binding of the substrate), and the allosteric site, onto which noncompetitive inhibitors may bind
What’s an allosteric site?
It’s a site onto which noncompetitive molecules can bind in order to change the shape of the active site, preventing the attachment of substrates
What happens if the concentration of the substrate increases in the presence of enzymes that have noncompetitive inhibitors attached to them?
Nothing will change, the enzymes will continue to be prevented from facilitating reactions because of the lack of attachment of substrates
