Enzymes Flashcards
all metabolic reactions are controlled by ____
enzymes
what are enzymes?
protein molecules that act as biological catalysts that control rate of reactions that take place in cells
what are catalysts?
chemical substances that speed up reactions (accelerate) in living cells, but remain unchanged at the end so they can be reused
what is metabolism?
sum of all chemical reactions that take place in a living organism
each step in the metabolism pathway is ___ by enzymes
catalysed
metabolism can either be ____ or _____
anabolic, catabolic
what is anabolic metabolism?
building up simple molecules to large complex compounds
what is catabolic metabolism?
breaking down complex compounds to simple ones
what is the role of enzymes in metabolism?
LOWER the activation energy required to start a reaction
helps speed up reactions
do enzymes provide activation energies?
NO
what are enzymes composed of?
protein molecules made by living cells
what are globular proteins in enzymes?
long chains or amino acids that have been folded up into a specific shape
the function of an enzyme relies on its ____
shape
what are the active sites on an enzyme?
active sites where substrate will bind to
what is an enzyme substrate complex?
molecule formed when substrate bonds to active site on an enzyme
what are the 4 factors affecting enzyme activity?
- substrate specifity
- substate concentration
- temperature
-pH
what is substrate specifity in enzyme activity?
each enzyme only binds to one specific type of substrate, thus the type of substrate affects enzyme activity
what is substrate concentration in enzyme activity? limits on concentration?
higher concentration, higher rate of reaction until all available enzymes are being used to catalyze reactions (saturation point)
can enzyme activity increase past the point of saturation?
nope
what are the effects of temperature on enzyme activity? limits on temps?
higher temp– higher rate of reaction
lower temp– lower rate of reaction
in extremely high temps, the shape of the enzyme changes and thus becomes denatured and inactive
after point of denaturation, can enzyme activity increase?
no, it falls steeply
what are the effects of pH on enzyme activity?
each enzyme acts best at a particular pH (optimal pH)
changes in pH can change shape of enzyme, thus becomes less efficient
