Enzymes Flashcards
Thousands of chemical reactions…
Are constantly going off in living things, so they need to be carefully controlled.
What does heating up a chemical reaction do? (pos/neg)
Positive- Speeds up reaction.
Negative- Speeds up unwanted reactions.
If you raise the temp. too much the cells will become damaged.
What is a catalyst?
A substance which increases the speed of a reaction without being changed or used up in the reaction.
Enzymes are what? (2)
Large proteins, made up of chains of amino acids which are folded into unique shapes needed for them to work. They act as biological catalysts.
Enzymes reduce the need for what?
High temperatures, we only have enzymes to speed up chemical reactions in the body.
What is the structure of an enzyme?
Each enzyme has an active site with a unique shape that fits onto the substance involved in the reaction.
Enzymes only catalyse…
One specific reaction because the substrate has to fit into the active site, and if it doesn’t the reaction won’t be catalysed.
What is the simple enzyme model called?
The lock and key model.
What happens in the induced fit enzyme model?
The active site changes shape a little as the substrate binds to it to get a tighter fit
Changing the temp…
Changes the rate of an enzyme catalysed reaction.
If it gets too hot… (2)
The bonds holding the enzyme together will break, changing the enzymes active site meaning the substrate won’t fit. The enzyme is said to be denatured.
What is an optimum temperature?
The temperature the enzymes work best at, they all have one.
How does PH affect enzymes?
If it’s too high or low the enzyme will become denatured.
Amylase:
Starch –> sugar
Amylase is found in: (3)
Saliva, the pancreas and the small intestine.
