Enzymes Flashcards
what is an enzymes tertiary structure?
globular proteins
what are scaffolding proteins?
the site of multiple enzymes working together to complete the same task
is the active site a small or large section of an enzyme?
a small portion
what is the equation of the active site?
binding site + catalytic site = active site
what is the activation energy?
the initial investment of energy to being the reaction and form the unstable intermediate
what is the transition state?
the unstable intermediate
how can the transition state occur?
adding heat
catalysts
what does the activation energy do to the viability of the reaction?
it makes the production of the final product energetically favorable
what happens to the activation of the reaction when an enzyme is used?
the activation energy is much lower
can enzymes change an endergonic reaction to an exergonic reaction?
no
are enzymes specific to reactions?
yes
how can enzymes lower the activation energy?
re-orientating substrates to increase efficiency allowing them to react
distorting substrate bonds allowing them to move to the transition state
adjusting the micro-environment of the substrates to allow substrates to interact and form product bonds.
what are cofactors?
non-protein chemicals that can aid biological reactinos
what are examples of inorganic cofactors?
pH, temperature and phosphorylation
what are examples of organic cofactors?
co-enzymes, often essential nutrients and minerals
what are cosubstrates?
transient cofactors
what is the equation for inactive + cofactor = whole active enzyme
apoenzyme+cofactor=whole active enzyme
what is a competitive inhibitor?
something that binds to the active site blocking the substrate
what is an example of a competitive inhibitor?
penicilin
what is a non-competitive inhibitor?
something that changes the shape of the binding site allowing the enzyme to react with different substrates
what is an example of a non-competitive inhibitor?
lead - where the inhibitor fully reduces the rate of reaction the enzyme is capable of
which can be out-competed - competitive or non-competitive inhibitors?
competitive inhibitors can be out-competed by increasing substrate concentration. this isn’t always possible with non-competitive inhibitors
what is an example of an irreversible inhibitor?
toxins and poisons e.g. CO
what are reversible inhibitors?
allosteric - usually w/ enzymes with multiple active sites and different substrates.
what is an example of allosteric inhibitors?
co-operative binding e.g. O2 and haemoglobin
