enzymes Flashcards
What is chemical equilibrium?
The state at which there is no net change in concentration of reactants
Under what condition is a reaction spontaneous?
The free energy of the substrate is higher than that of the product
Most enzymes are _,, but some are _
Proteins, RNA
Give an example of a place where RNA molecules are used as enzymes
On ribosomes, ribosomal RNA cayalyses the synthesis of proteins
Give 3 reasons for why the transition state is high in energy
Due to the rearrangement of bonds
Formation of transient charges
Distortion/change in position of chemical groups
What does the amplitude of activation energy determine?
The rate of reaction, by an inverse relationship
How do you lower the activation energy?
By stabilising the transition state
What kind of interactions stabilise the complex between enzyme and substrate at the transition state?
Summation of many weak non covalent interactions (binding energy)
Transient covalent bonds at active site of enzyme
How is binding energy represented on a coordinate diagram?
It is the difference between the free energy of the transition state of the catalysed and uncatalysed reaction
Why is the lock and key (Fischer) model not accurate?
Excessive stabilisation of enzyme substrate complex would decrease free energy to below the substrate alone, thereby increasing activation energy
The induced fit model assumes that there is optimum weak interactions between enzyme and substrate at the transition state. What other assumption is made?
That there is a conformational change upon binding that positions chemical groups between enzyme and subtrate in such a way that catalysis is favoured
Many weak interactions between substrate and surrounding water are _
Replaced by weak interactions with enzyme. Further contributes to binding energy
