B1.2.3 Enzymes Flashcards
What are biological catalysts?
Substances that speed up a reaction without being used up themself.
Once a reaction is finished they can be reused to catalyse the same type of reaction again
Enzymes are involved in many reactions in your body. For example?
build larger molecules from small ones, such as in protein synthesis
break down large molecules into smaller ones, such as in digestion.
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
What is the substrate
The molecule that binds to the active site of the enzyme
Difference between enzyme and substrate?
Enzymes: Biological catalysts that speed up chemical reactions in living organisms
Substrates: Specific molecules of which enzymes bind to their active sites
Do enzymes bind to all molecules?
Enzymes are highly specific.
This means they can only bind to one type of substrate molecule.
The substrate must fit exactly into the active site.
If it does not, the molecule cannot 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
Explain why an enzyme that binds to glucose cannot bind to glycogen. (3)
-An enzyme that binds to glucose cannot bind to glycogen because enzymes have specific shapes that only allow them to bind to molecules that fit into their active sites
-The active site of the enzyme that binds to glucose is shaped to accommodate a single glucose molecule, and it cannot effectively bind to the larger and more complex structure of glycogen
-Therefore, the enzyme cannot catalyze reactions involving glycogen.
Explain why an enzyme that binds to glucose cannot bind to glycogen. (3)
-An enzyme that binds to glucose cannot bind to glycogen because enzymes have specific shapes that only allow them to bind to molecules that fit into their active sites
-The active site of the enzyme that binds to glucose is shaped to accommodate a single glucose molecule, and it cannot effectively bind to the larger and more complex structure of glycogen
-Therefore, the enzyme cannot catalyze reactions involving glycogen.
Explain why an enzyme that binds to glucose cannot bind to glycogen. (3)
-An enzyme that binds to glucose cannot bind to glycogen because enzymes have specific shapes that only allow them to bind to molecules that fit into their active sites
-The active site of the enzyme that binds to glucose is shaped to accommodate a single glucose molecule, and it cannot effectively bind to the larger and more complex structure of glycogen
-Therefore, the enzyme cannot catalyze reactions involving glycogen.
Another difference between enzyme and substrate
At the end of a reaction, the enzyme is left unaltered whereas the substrate will have changed
