ch 6 - Enzymes Flashcards
efficiently and selectively catalzye chemical reactions
enzymes
how do enzymes contributes to human health?
- can pathologically impact diseases
- therapeutic causes (target specific enzymes in body)
- indicate diseases (biomarkers)
true or false. all enzymes are proteins, and all proteins are enzymes.
false. all enzymes are proteins but not all proteins are enzymes
how are enzymes classified?
into 6 groups, based on the type of reaction they catalyze
3 characteristics of catalysts
- lower E needed for rxn to proceed
- speed up attainment of equilibrium but dont change equilibrium
- unchanged by the rxn
Enzymes ________ increase the rates of reaction.
Enzymes ________ affect the equilibrium of the reaction.
Do
Do not
how does substrate binding promote reactions?
- reduces the entropy
- dissolves the substrate to expose reactive enzymes
- aligns functional groups of enzyme with substrate
- distorts substrates
- induced fit of enzyme in response to substrate binding
explain transition state binding in enzymes
- enzyme distorts the substrate, forcing it toward transition state
- enzyme must be shape and chemically compatible
- enzyme changes shape without breaking to fit into a binding site
name the equation:
Vo = Vmax[S]
Km + [S]
Michaelis-Menton
- measures relationship between velocity and substrate concentration
what is Km?
- amount of substrate required for enzyme to be functioning at 1/2 maximal velocity
what is a Lineweaver-Burk plot?
- describes relationship b/w [S] and Vo
- double reciprocal of 1/Vo vs 1/[S]
- more precise was to analyze kinetic data
- determines Vmax and Km
what is kcat?
- enzyme turnover number
- number of molecules of substrate converted to product per unit time under saturated conditions
- cVmax/[Et]
What reversible enzyme inhibitor is being described and name an example.
- usually resembles substrate
- can only bind to free enzymes
- results in a increase in Km, and a decrease in affinity for substrate molecule
- Competitive inhibitor
- example: transition state analogue
- normal crosses y-axis at same point as inhibitor
What reversible enzyme inhibitor is being described?
- bind only to enzyme substrate
- vmax and km are both decreased
- Uncompetitive inhibitor
- lines are parallel on graph/plot
Name the enzyme inhibitor.
- binds both enzyme and enzyme substrate
- vmax decreases and theres no change in km
- noncompetitive inhibitor
- start at same spot on graph, but the noncompetitve inhibitor crossed the y-axis higher up than the no inhibitor
