W7 - Enzymes as Drug Targets Flashcards
What are enzymes
Enzymes are biological catalysts that speed up the pace of chemical reactions, which are central to all aspects of cellular function in both prokaryotic and eukaryotic cells
What is the active site
Enzymes have specialized binding sites that are specific for certain substrates, once bound (via non covalent bonding) the substrate is then modified and released
What is the effect of an enzyme of the kinetics of a reaction
The enzyme lowers the activation energy for a reaction to take place. So less energy is required for the reaction to take place so it is more likely to occur
What is activation energy
Minimum amount of energy needed for a reaction take place
What is Vmax
the maximum rate at which an enzyme can carry out a reaction
What is Km
Substrate concentration at which the enzyme will work at 1/2 v max
Where do you see vmax and Km
Rate concentration graph
Lineweaver burke plot
what is a Lineweaver burke plot
it is a linier plot using data to calculate both Km and Vmax
What are the two types of inhibitio
reversible
irreversible
what are the two categories of inhibition
competitive
Non competitive
How does competitive inhibition work
The inhibitor binds to the active site, meaning that the substrate cannot form an enzyme substrate complexes so less reactions taking place
What is the result of competitive inhibition on the Km
Km value gets larger
What is the result of competive inhibition on the Vmax
does not change
Describe non competitive inhibition
Inhibitor binds to an enzyme at its allosteric site (away from the active site) changing the shape of the active site meaning that enzyme substrate complexes cannot form
What is the result of non competitive inhibition on the Km
Does not change
What is the result of non competitive inhibition on the Vmax
Increases
What is the result of enzymes being turned off in bacteria and viruses
If the enzymes produced by infectious agents can be switched off this can be fatal for the bacteria or virus in question.
What do the best bactericidal drugs target
DD transpeptidases
Why are DD transpeptidases good to target
It carries out crosslinking of peptidoglycan wall subunits so when it is inhibited it prevents the building of new bacterial cell walls.
What happens as a result of beta lactam drugs
Produces an enzymatic defense system and it is part of the reason there are some forms of antibiotic resistance
What does altering regulatory enzyme function do to the body
Alters the physiological function downstream of that enzyme
What can targeting enzyme function be used for
Can be used to modulate human physiology
What is a common cause of disease
Mutations, changes in the protein sequence leads to a variety of human diseases due to altered enzymatic function
