B1.2.3 - Enzymes Flashcards
What are enzymes?
Enzymes are biological catalysts, meaning they speed up reactions without being used up themselves. Enzymes can be reused to catalyse more reactions.
What are enzymes made of?
Proteins
Give two examples of enzyme reactions
Building larger molecules from small ones, such as in protein synthesis
Breaking down large molecules into smaller ones, such as in digestion
What do enzymes look like?
Enzymes are made up of long chains of amino acids. These are folded together to form a specific shape. The active site’s shape is very important as this is where the molecules of substrates bind to the enzyme
What is a substrate?
A substrate is the molecule that binds the the enzyme. When it binds to the active site, the substrate fits inside the enzyme
Do enzymes bond to all molecules?
No, as enzymes are highly specific - they can only bond to one type of substrate molecule. The substrate must fit exactly into the active site, if not, the molecule cannot bind
What is the hypothesis used to describe the Enzyme-Substrate bonding?
The Lock and Key hypothesis. The enzyme being like a lock, and the substrate like a key. Only one key will fit the lock and be able to turn to open the door. This is how enzymes are thought to work
What happens when the substrate binds to the enzyme?
Firstly, an enzyme-substrate complex is formed. The reaction then happens quickly, and the products are released from the enzyme. The enzyme is then ready to catalyse another reaction
