Enzymes Flashcards
(21 cards)
What are oxidoreductases
Enzymes that catalyze the transfer of electrons
What are transferases
Enzymes that catalyze the transfer of functional groups
What class of enzymes use water to break a covalent bond
Hydrolases
What are lyases
Enzymes that catalyze the breaking of covalent bonds
What enzyme reaction can lead to the formation of new bonds
Lyases
What are isomerases
Enzymes that convert a molecule from one isomer to another
What are ligases
Enzymes that catalyze the joint of two molecules by forming a new bond
What is a substrate
A molecule that an enzyme reacts with
What is enzyme-substrate complex
A reversible association between an enzyme and substrate
Where does catalysis occur
Enzyme-substrate complex
Active site
The pocket on the enzymes where the substrate binds and the reaction takes place
An example of a substrate
ATP
Why is an uncatalyzed reaction rate slower
It doesn’t possess a catalyst so the activation energy is larger thus making the rate slower
Where is the highest energy point in an uncatalyzed reaction
The transition state
What does an uncatalyzed reaction look like
S->S*->P
An enzyme catalyzed reaction look like
S+E->E.S->E.S*->E.P->E+P
Explain the transition state theory
The rate of a chemical reaction depends on how much energy a substrate can acquire to reach its transition state
Why does S* have a higher energy than S
Because S* undergoes bond stretching or bending in order to react(distortion)
What type of reactions are formed when E binds to S
Hydrogen bonds
Hydrophobic interactions(Van der waals)
What are some effects of the E.S formation
Decrease in entropy of S
Desolvation (removal of H2O shell around S)
Induced fit: the enzyme adjusts to the shape of S*
Alignment of groups that must react
How does an enzyme recognize and binds a substrate
Shape consistency(the substrate must fit the active site)
Electrostatic consistency(correct matching of H-bonds and ionic within the active site
Thermodynamic consistency: can the protein flex to adopt a substrate or the substrate flex to fit active site
