Topic 4- Enzymes Flashcards
What is the activation energy
the amount of energy necessary to bring the molecules together to react
What are enzymes
They are biological catalysts, they speed up the rate of chemical reactions in living organisms
Why is the fact the enzyme is uncharged at the end of a reaction important
It allows it to be reused
What is the structure of an enzyme
A globular protein with a Specific tertiary structure maintained by ionic disulphides and hydrogen bonds
What is required for a reaction to occur
Activation energy
What is the functional region of an enzyme
The active site
What is the active site
A specific intended area on the surface of the enzyme formed by specific folding of amino acid chain
What is formed when an enzyme substrate molecule enters the active site
An enzyme substrate complex
How does the substrate molecule attach to the active site
The amino acids around the active site attach to the substrate molecule using hydrogen bonds and hold it in position while the reaction takes place
What happens if the tertiary structure of an enzyme is broken down
The active site changes shape and becomes denatured
What is the lock and key theory
The enzymes active site is a complimentary shape to the substrate, the substrate enters the active and forms an ESC, and products are formed. There is only one substrate that fits specifically to an active site of an enzyme
What factors can change the shape of an enzyme
Temperature and pH
What is an inhibitor
Molecule that reduces the ability of an enzyme to speed up a reaction
What can be used to maintain a constant pH value
A buffer
Give example of an immobilised enzyme
Alginate beads, gel membranes, cross linking
What does immobilised mean
Enzyme that are bound to inert supports or trapped in a matrix
What is an inhibitor
Molecules that reduce the ability of an enzyme to speed up a reaction
What are the two types of inhibitor
Competitive and non competitive
What is the importance of buffers in enzyme experiments
They maintain a constant pH which is important as enzymes are sensitive to small changes in pH
What are the advantages of using immobilised enzymes
More stable at higher temperatures and can tolerate wider range of pH values
What are the two theories explaining enzyme action
Lock and key theory
Induced fit theory
Which theory explains the action of a lysozyme
Induced fit
Describe the induced fit theory
The active site alters the shape slightly to fit the substrate the enzyme substrate complex is formed and products are released the enzymes active site then returns to its original shape
What conditions change the 3D structure of enzyme molecules
Temperature and pH
