Enzymes Flashcards
What is a enzyme
A enzyme is a protein created by living organisms used as a catalyst to speed up reactions. Usually end in ase
What is a catalyst
Catalysts speed up the reaction by lowering the activation energy
Exergonic
Less energy in products then reactants, meaning there was a release of energy, Which is a type of catabolic reaction
Endergonic
There is more energy in the products compared to the reactants, meaning there was a I out of energy, anabolic reaction
Ways to decrease the activation energy
M: Microenvironment (creating a favorable environment for bonding)
O: Orientation (positioning the substrate in the correct alignment)
D: Direct Participation (enzyme involvement in the reaction)
S: Straining Bonds (enzymes distort bonds to make them easier to break)
Why we use enzymes instead of heat
Heat could speed up the reaction, but that would cause the protein to lose their shape and function, whereas enzymes speed up the reaction without causing the shape or function to change. Also, their not consumed, meaning we recycle them
Enzyme shape
The shape of a enzyme is specific for a specific substrate. There is only one substrate per enzyme
Enzyme substrate complex
Substrate bind to an active site on the enzyme. And induced fit model is a process in which the enzyme will change shape to hold its substrate
Anabolic reaction
Requires a input of energy, and produces more complex products
Anabolic Reactions - 7 Steps
- Substrate binds to the active site
- Substrate is held in active site by hydrogen and ionic bonds
- Enzyme changes shape to embrace substrate (induced fit model)
- Enzyme lowers activation energy and speeds up reaction
- Substrate(s) are converted into new products, new bonds are formed
- Produce are released
- Active site is available again
Catabolic reaction
Results in the release of energy and less complex products
Factors that effect enzyme activity
- Substrate concentration
- Optimal temperature
- Optimal pH
Enzyme co factors
• Cofactors activate enzymes or proteins
• needed for some enzymes to function
Coenzyme
Organic cofactors that transfers energy in the form of electrons
Allosteric regulation
• Allosteric regulation is a way cells control enzyme activity to coordinate cellular activities.
• instead of binding to a active site, molecules can bind to a allosteric site, which causing a conformational change, meaning a shape change can either activate or inhibit the enzyme’s function by affecting how it interacts with the substrate.
Allosteric activation
Allosteric activators bind to the Allosteric site stabilizing its shape, making to more likely to interact with a substrate
Allosteric inhibitors
Binds to the Allosteric site, reducing the enzyme activity, by changing its shape in a way that prevents it from interacting with substrates
It’s considered a non competitive inhibitor
Competitive inhibitors
Molecules that have a similar shape to the specific substrate for a enzyme, but not quite, and bind to the active site, preventing the true substrate from binding
Feedback inhibitor
• A sequence of catalyzed reactions
• the product of one reaction is the substrate for the next enzyme
• eventually the product created is the inhibitor for the previous reaction which slows down the reaction
