enzymes Flashcards
what are anabolic reactions
build components up
needed for growth
what are catabolic reactions
break components down
needed for energy
metabolism
sum of all the reactions and reaction pathways occurring in a cell or organism
Vmax
maximum rate of reaction
activation energy
energy needed for the reaction to start
enzymes reduce the activation energy
lock and key hypothesis
substrate complementary to active site, substrate binds to active site creating an enzyme substrate complex, reacts to form enzyme product complex , R groups interact with substrate forming temporary bonds putting strain on bonds within substrate
induced fit
modified version of lock and key, active sight changes slightly as substrate enters, initial interaction weak but causes changes in tertiary structure that strengthen binding and put pressure on substrate lowering activation energy
intracellular enzymes
enzymes that act within cells
catalase
ensures hydrogen peroxide is broken down to oxygen and water quickly
extracellular enzymes
enzymes that are released from cells to break down large molecules into smaller ones through digestion, work outside the cell
digestion of starch
starts in mouth and continues to the small intestine
amylase converts starch polymers into maltose, produced by salivary glands and pancreas
maltase breaks down maltose into glucose glucose then absorbed by cells
digestion of proteins
trypsin (a protease) converts proteins into smaller peptides. produced in pancreas. amino acids then absorbed by cells
effect of temperature on enzyme action
as temp increases kinetic energy increases collide more frequent more frequent successful collisions increase rate of reaction too high temp breaks bonds within enzyme changing active site causing denaturisation
Q10
temperature coefficient, measure of how much the rate of a reaction increases with a 10°C increase in temp. for enzymes its usually 2 meaning it doubles
optimum temperature
the temperature at which the enzyme has the highest rate of activity
