Topic 8 Flashcards
(21 cards)
Enzymes are _________. They _______ reactions by forming a ______________ complex.
Enzymes are PROTIENS. They CATALYZE reactions by forming a ENZYME SUBSTRATE COMPLEX.
What do Gibbs free energy diagrams show? Do enzymes change delta G?
Gibbs free energy diagrams show, the energy difference between products and reactants, exergonic vs endergonic.
ENZYMES DONT CHANGE DELTA G.
Whats the x axis and whats the y axis in a Gibbs free energy diagram
X axis: Direction of reaction
Y axis:Free energy
What is the transiton state?
The transition state is the point of highest free energy needed. This is an unstable state
What is activation energy?
Activation energy is the difference between free energy state and the transition state.
What do enzymes do to activation energy?
Enzymes reduce the activation energy of a reaction.
What is an exergonic reaction?
An exergonic reaction is a reaction that releases energy.
What is an endergonic reaction?
An endergonic reaction is a reaction that requires energy input.
Chemical reactions turn ______ into ________.
Chemical reactions turn SUBSTRATES into PRODUCTS.
Whats binding affininty?
Binding affinity is, how attracted a substrate is to its enzyme.
What is Rate of Catalysis?
Rate of Catalysis is how fast an enzyme can go through a cycle of enzyme action.
What two things do Michaelis-Menten Kinetic graphs show us?
1)Binding affinity
2)Maximum catalytic rate (reaction speed)
How is reaction rate determined?
Reaction rate is determined by the slope of a product vs time graph.
What does it mean when an enzyme is saturated?
When an enzyme is saturated, this means all the active sites are full.
What is Vmax?
Vmax is the leveling point-its the maximum initial velocity.
What is Km?
Km is, when the initial velocity is 1/2 Vmax.
What is a cofactor, and what are some examples?
Cofactors are inorganic and required for protien and enyzme function.
Ex:Zinc, iron, copper
What are coenzymes, and whats an example?
Coenzymes are organic molecules needed for enyzme function.
Ex:Vitamins
What are competitive inhibitors? Whats their application?
Competitive inhibitors bind in the active site of an enzyme and block substrate binding.
APPLICATION: Increases KM not VMAX
What are non-competitive inhibitors? What is their application?
Non-competitive inhibitors bind to an allosteric site (somewhere other than the active site) and causes a conformational shift.
APPLICATION: Changes VMAX not KM
What are uncompetitive inhibitors? What is their application?
An uncompetitive inhibitor binds to the enzyme substrate complex once substrate is bound to enzyme and
1)blocks the ability of the substrate to dissociate
2)blocks the ability of the enzyme to catalyze the chemical reaction
APPLICATION: Decreases KM and VMAX
