Enzymes Flashcards
(14 cards)
What are enzymes
Proteins that act as biological catalyst
Affect metabolism
Tertiary structure determines AS
Forms ES complex - lowers activation energy
Explain the induced fit model of enzyme action
Shape of AS is not directly complementary to the substrate
Change angles ES complex - after conformational change
Lowering activation energy
Explain the lock and key model
AT determined by tertiary structure
Name 5 factors that affect the rate of enzyme controlled reaction
Enzyme concentration Substrate concentration Concentration of inhibitors pH Temperature
How does substrate concentration affect rate of reaction
Rate increases proportionally to substrate concentration
Rate levels off when max number of ES complexes form
How does enzyme concentration affect the rate of reaction
Proportionally
Rate levels off when max number of ES complex form at any give time
How does temperature affect
Increases as kinetic energy increases, peaks optimum temperature
Above optimum, ionic and H bonds structure breaks
De natures
What is the temperature coefficient
Q10- measures the change in rate of reaction per 10
How does pH affect rate of reaction
Enzymes have a narrow optimum pH range
Outside range, hydrogen and hydroxyl ions interact with H bonds and ionic bonds = denaturation
How do competitive inhibitors work
Bind to AS
Temporarily prevent ES complexes
Increasing the substrate concentration, decrease their effect
How do non competitive inhibitors
Trigger change of active site
Increasing substrate concentration has no impact on their effect
What are irreversible inhibitors
Permanently prevent formation of ES complexes
What are reversible inhibitors
May be competitive or non competitive
Define metabolic poison
Substances that damage cells
