Enzyme action Flashcards
What kind of protein is an enzyme?
Globular
What do enzymes act as?
Biological catalysts
Why is it necessary for organisms to have enzymes?
Enzymes speed up the rate of reactions without the need of high pressures or temperatures which would ultimately damage the cell.
Enzymes can only increase the rate of reaction up to a certain point. What is this point known as?
Vmax
What is meant by the activation energy?
The amount of energy needed to be applied for a reaction to start
What are the names of the two hypothesis for how enzymes behave?
Lock and key hypothesis
Enduced-fit hypothesis
What is the name for the part of the enzyme which is completely specific to a substrate?
The active-site
What is the name of the molecule which binds to the enzymes active-site?
The substrate
What is meant by the lock and key hypothesis?
Just like only a specific key can fit into the right lock, only a specific substrate will fit into the active site of the right enzyme.
What is said to be formed when the substrate is bound to the active site of an enzyme?
An enzyme-substrate complex
How is the substrate temporarily bonded to the enzymes active site?
The R-group within the active site of the enzyme forms temporary bonds with the substrate.
Draw a simplified diagram of the lock and key hypothesis
What is meant by the induced fit hypothesis?
The active site of the enzyme changes shape slightly to completely fit the shape of the substrate.
Bond strength
How does, according to the induced fit hypothesis , the enzyme lower the activation energy of a reaction?
The weak interactions between the enzymes active site and the substrate induces changes in the enzymes tertiary structure. These changes put strain on the substrate and may weaken bond(s) within the molecule; thus lowering the activation energy.
