B1.2.3 Enzymes Flashcards
What are enzymes?
Enzymes are made of protein.
They are biological catalysts
Once a reaction is finished, they can be used to catalyse the same type of reaction again
What are biological catalysts?
Substances that speed up a reaction without being used up themself
Enzymes are involved in many reactions in the body. Name two examples.
In protein synthesis: building larger molecules from small ones
In digestion: BREAKS DOWN larger molecules INTO smaller ones
What do enzymes look like?
- Enzymes, like all proteins are made up of long chains of amino acids
- These are folded together to form a specific shape
The shape of one part of the enzyme is particularly important. Name and describe it
The active site - part of the enzyme where the substrate binds
What is the substrate?
A substrate that reacts to an active site of an enzyme
Do enzymes bind to all molecules? (3)
Enzymes are highly specific
This means that they can only bind to one type of substrate molecule.
The substrate mist fits exactly into the active site, if not the molecule can not bind.
What is the lock and key hypothesis? (2)
The enzyme being like a lock and the substrate like a key.
Only one key will fit the lock and be able to open the door
What is one difference between an enzyme and a substrate?
At the end of a reaction, the enzyme is left unaltered whereas the substrate will have changed
Explain why an enzyme that can bind to glucose CANT bind to glycogen (2)
Since enzymes are highly specific, and can each only bond to one kind of substrate.
If the enzyme has already bonded to glucose, it can’t bind to another like glycogen
What happens after the enzyme-substrate complex is formed?
The products are released from the enzyme.
The enzyme is then ready to catalyse another reaction
