1.7 - Enzymes Flashcards
Enzymes
Speeds up chemical reactions by lowering activation energy
Almost all processes in the cell need enzymes in order to occur
Not consumed during a reaction
what do substrates do
Substrates bind to an active site and form an enzyme-substrate complex
Induced fit hypothesis
Active site undergoes a conformation change to better accommodate the substrate.
Enzymes are specific to their substrate and
1 substrate per enzyme
How do enzymes make a product?
Substrate enters Enzymes active site, enzyme changes shape to fit better. becomes enzyme-substrate complex. Product leaves enzymes active site
Why do we need enzymes
Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems.
How do enzymes affect activation energy?
Enzymes lower activation energy by making an enzyme/substrate complex.
anabolic reaction
Energy+smaller molecules->larger molecules
catabolic reaction
larger molecule->smaller molecules+energy
cofactors
often metal that binds to an enzyme to catalyse a reaction
coenzyme
organic cofactor, often from vitamins.
acts as transport molecules to move molecules from one enzyme to another.
4 conditions that affect enzyme activity.
enzyme and substrate concentration
enzyme inhibitors
temperature
pH
what does Enzyme and Substrate Concentration affect?
the speed of the reaction is proportional to enzyme concentration. if the saturation concentration of the enzyme is limited, the reaction will become saturated.
enzyme inhibitor
competitive: Inhibitor molecule fits into the active site of the enzyme and blocks substrates.
non-competitive: Inhibitor molecule binds to a site that is not the active site, however, the binding causes a deformation of the enzyme,
Allosteric Control
a molecule binds to a site that is not the active site, causing a deformation of the enzyme.
What happens if an enzyme isnt in the right temperature and pH range?
Outside of these ranges, reactions are slower or do not happen.
