Enzymes Flashcards
In a living organism chemical reactions take place. These reactions can happen more quickly by raising the temperature. However, there is a limit to how high the temperature can be. Why is that?
If the temperature is too high cells will start to get damaged.
What do living organisms produce the actors biological catalysts?
Enzymes
What are the benefits of having enzymes?
They reduce the need for high temperatures and we have enzymes to speed up useful chemical reactions.
What is the textbook definition of a catalyst?
A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction.
What are enzymes made of?
Large proteins that are made up of chains of amino acids.
What do chemical reactions usually involve?
Things either being split apart or join together.
What do enzymes have that have a unique shape to fit onto the substance involved in a reaction?
An active site
How many reactions can one type of enzyme catalyse and why?
One type of enzyme can only catalyse one type of reaction. This is because the substrate has to fit in the active site. If it doesn’t, then the reaction won’t be catalysed.
What is a substrate?
A substance that an enzyme act on.
Enzymes active site can change shape slightly to get a tighter fit on the substrate. What is this called?
An ‘induced fit’
Like any other reaction, raising the temperature can increase the rate of an enzyme catalysed reaction. What happens if the temperature gets too hot in this specific reaction?
Some of the bonds holding the enzyme together will break. This changes the shape of the enzymes active site so the substrate will not fit anymore.
What do we call an enzyme when the active site changes and the substrate doesn’t fit anymore?
Denatured
Relatively, what temperature do enzymes work best at?
Their optimum temperature
As well as the temperature, what else can affect the bonds holding the inside together?
The pH level
What is the optimum pH level normally?
Neutral pH 7
Name an example of an enzyme that doesn’t work best at pH 7.
Pepsin breaks down proteins in the stomach and works best at pH 2.
