1.7 Enzymes Flashcards
What are enzymes
a biological catalyst
Function of an enzyme
Speeds up chemical reactions, may break apart a single molecule or
bond other molecules together
True or false? Enzymes help to break down/build molecules
True
True of False? Enzymes are not reusable
False
Substrate
the substance that reacts with
an enzyme
Active Site
a pocket/groove in an enzyme that
binds to the substrate
Induced-Fit Hypothesis
describes how enzymes
change shape to better attach to a substrate
Enzyme-Substrate Complex
term used to describe
enzymes bonded to substrate(s)
Cofactor
non-protein
group that binds to
enzymes and helps them
function
Examples of cofactors
Often metals such as
copper, iron, zinc etc.
Coenzyme
an organic
molecule that acts as a
cofactor of an enzyme
Coenzyme source
may be derived from
vitamins
5 factors that Affect Enzyme Activity
Concentration, Enzyme inhibitors, allosteric regulation, feedback inhibition, temperature & pH
Concentration and Enzyme Activity
the concentration of both enzyme and
substrate will influence the rate of reaction (Rate of reaction is proportional to Enzyme
Concentration)
Enzyme Inhibitors and Enzyme Activity
Bind to enzymes to inhibit activity (Lower enzyme reaction rate)
2 types of enzyme inhibitors
Competitive Inhibitor & Non-competitive Inhibitor
Competitive Inhibitor
binds to active site to prevent
substrate from binding
Non-competitive Inhibitor
binds to enzyme and changes the
shape, indirectly prevents substrate from binding
True or false? Enzyme inhibitors are always reversible
False. May be reversible or irreversible
True or false? Irreversible Inhibitors are often highly toxic to cells as they
prevent enzymes from functioning
True
Allosteric Regulation
regulation of enzyme
function using other molecules that bind to the
enzyme
Allosteric Site
a binding site on an enzyme where
allosteric molecules attach
Allosteric Inhibition
stabilizes enzyme into an
inactive form (turns enzyme off)
Allosteric Activation
stabilizes enzyme into an
active form (turns enzyme on)
Feedback inhibition
the regulation of a
pathway by one of the products of the
pathway (once enough product is produced
then the pathway shuts down until more
product is needed)
Temperature and pH
Enzymes will often only function optimally within a specific range of temperatures and
pH levels
Application of Enzymes
Treating Lactose Intolerance – take
lactase pills to help break down lactose
in dairy products
Making Cheese – enzymes used to
solidify milk into cheese
Breaking Down Starch – enzymes used
to break down plant starches into sugars
Stain Removal – used to break apart
certain types of staining molecules
without heating
