Enzymes Flashcards
What is an enzyme?
An enzyme is a catalyst produced by living things.
What is a catalyst?
A catalyst is a substance which increases the speed of a reaction, without being changed or used up in the reaction.
What does every enzyme have?
Every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction.
What is a substrate?
A substrate is the substance that an enzyme acts on..
What happens if the substrate doesn’t match the enzymes active site?
The reaction won’t be catalysed.
What is the optimum temperature?
Where the enzyme is most active.
What 2 things affects enzymes?
Temperature and pH.
What happens when the temperature gets hot with an enzyme?
Some of the bonds holding the enzyme together break - this changes the shape if the enzyme’s active site so the substrate won’t fit anymore - the enzyme becomes denatured.
How does pH affect an enzyme?
If the pH is too high or low it interferes with the bonds holding the enzyme together. This changes the shape of the active site and denatures the enzyme.
What is the optimum pH of an enzyme?
It is usually 7 but pepsin has an optimum pH of 2 - meaning it is well suited to the acidic conditions there.
In a graph what is the x and y axis for an enzyme and pH/temperature?
pH - X axis is pH - Y axis is Rate of Reaction
Temp - X axis is temp - Y axis is Rate of Reaction
What is different between graphs with pH and temp?
pH graphs don’t start at (0,0) but temp graphs do.
What happens in a graph when an enzymes reaches its optimum pH/temperature?
The RoR goes down.
