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Max Pham
Mrs. Leslie
30 September 2014
AP Biology
Enzymes: Biological Catalysts: Reading Notes
1. Concept: An enzyme alters the activation energy of a reaction
Enzyme is 3D – allows it to associate with substrate (molecule that will go thru reaction)
Enzyme brings two substrates together in correct orientation (dehydration synthesis) or stresses bonds of substrate (hydrolysis) - lowers activation energy for new bonds to be formed/ broken
Different types of cells have different types of enzymes – affects structure/function of cell
Implication: Enzymes are vital for living things in that it speeds up reactions that, if a catalyst weren’t present, would not be able to occur fast enough.
2. Concept: Active sites of enzymes conform to fit the shape of substrates
Active site: place where substrate bind
Binding of substrate causes enzyme to slightly change shape – induced fit
Allows other substrates to bind with enzyme
Implication: nothing really that important to be honest
3. Concept: Environmental and other factors affect enzyme function
Temperature
Increase of temp causes uncatalyzed reaction to be faster due to more kinetic energy of reactants
HOWEVER: catalyzed reactions have an optimal temperature
Increase of temp below the opt temp will increase reaction rates
HOWEVER: once temperatures rises above opt temp, enzyme begins to break down (denature)
Implication: Enzymes have different optimum temperatures, depending on the type of organism. Human enzymes opt temp is about 35 Celsius while Prokaryotes in hot springs have opt temp of 70 Celcius Ph
Ionic interactions between charged amino acids also hold enzymes together
These interactions are sensitive to [H+] bc. changing concentration CHANGES THE BALANCE between negative and positively charged amino acids – therefore affects shape since these interactions hold enzyme together
Most enzymes ph range = 6-8
Some enzymes can maintain 3D shape even in extremely acidic/basic environment
Pepsin
Mrs. Leslie
30 September 2014
AP Biology
Enzymes: Biological Catalysts: Reading Notes
1. Concept: An enzyme alters the activation energy of a reaction
Enzyme is 3D – allows it to associate with substrate (molecule that will go thru reaction)
Enzyme brings two substrates together in correct orientation (dehydration synthesis) or stresses bonds of substrate (hydrolysis) - lowers activation energy for new bonds to be formed/ broken
Different types of cells have different types of enzymes – affects structure/function of cell
Implication: Enzymes are vital for living things in that it speeds up reactions that, if a catalyst weren’t present, would not be able to occur fast enough.
2. Concept: Active sites of enzymes conform to fit the shape of substrates
Active site: place where substrate bind
Binding of substrate causes enzyme to slightly change shape – induced fit
Allows other substrates to bind with enzyme
Implication: nothing really that important to be honest
3. Concept: Environmental and other factors affect enzyme function
Temperature
Increase of temp causes uncatalyzed reaction to be faster due to more kinetic energy of reactants
HOWEVER: catalyzed reactions have an optimal temperature
Increase of temp below the opt temp will increase reaction rates
HOWEVER: once temperatures rises above opt temp, enzyme begins to break down (denature)
Implication: Enzymes have different optimum temperatures, depending on the type of organism. Human enzymes opt temp is about 35 Celsius while Prokaryotes in hot springs have opt temp of 70 Celcius Ph
Ionic interactions between charged amino acids also hold enzymes together
These interactions are sensitive to [H+] bc. changing concentration CHANGES THE BALANCE between negative and positively charged amino acids – therefore affects shape since these interactions hold enzyme together
Most enzymes ph range = 6-8
Some enzymes can maintain 3D shape even in extremely acidic/basic environment
Pepsin