Enzymes Flashcards
What are catalysts?
Chemicals that increase the rate of chemical reactions and allow reactions to occur at lower temperature, without being used used themselves
What do catalysts do to the energy of a reaction?
Lower the activation energy
What are enzymes?
Biological protein catalysts found in living organisms
What do all enzymes have?
An active site
What is an active site?
An area where the substrate binds to the enzyme
What does the active site of an enzyme give it?
It’s specific nature
What kind of design are enzymes?
Lock and key fit design (induced model)- enzyme is the lock and substrate is the key
What factors affect enzyme reactions?
- pH
- Substrate concentration
- Temperature
- Competitive inhibitors
- Non-competitive inhibitor
How does pH affect enzymes?
Specific enzymes work best within a range of pH; if the pH is too low or too high the enzyme may denature
How does substrate concentration affect enzymes?
Higher substrate concentrations usually produce greater enzyme activity until all of the active sites are occupied
How does temperature affect enzymes?
Increased temperatures increases enzyme activity until the enzyme starts to denature. Very high temperatures breaks down proteins and render the enzymes ineffective
How do competitive inhibitors affect enzymes
Competitive inhibitors have a similar shape to the substrate and binds to the active site of an enzyme, preventing the desired reaction
How do non-competitive inhibitors affect enzymes?
Non-competitive inhibitors are molecules that attach to an enzyme, not the active site, but will still overall change the shape of the enzyme and hence close off the active site
What is denaturation?
A temporary change in the shape of the enzymes active site which closes it and does not allow substrate to attach
What are co-factors?
Inorganic ions that help enzymes combine with substrate molecules; come from minerals
