Enzymes Flashcards
What is meant by the term Biological Catalysts
Proteins used in metabolsim which lowers activation energy and is not used up in the reaction
How does an enzyme break down a substrate
Active site complementary to shape of substrate
Substrate enters active site
An Enzyme-Substrate Complex forms –> Induced-Fit Hypothesis which destabalises bond in substrate to form and Enzyme-Product Complex
Products leave Active Site
How does Cl- increase rate of reaction
It is a cofactor which bind to enzyme thus E-S-C forms more easily
How does inhibitor affect rate of reaction
Blocks substrate from entering and occupies it form a short time thus fewer Active Sites available
Explain graph of Rate of reaction against substrate concentration
Initial:
More Successful collisions occur
More E-S-C form
More product forms
End:
Enzyme’s active sites occupied
Enzymes at full capacity
Enzyme conc. is limiting factor
How does pH affect enzyme
Change in Ph causes:
Charges in enzyme ** to change
Ionic bonds broke/affected
Tertiary structure of active site changes so tertiary structure denatures** –> substrate no longer complementary to active site
Why do scientists now induced fit model
New studies show shape of enzyme slightly altered during reaction
Give examples of intracelluar and extracelluar enzymes
Intracelluar: Catalse
Extracelluar: Amylase and Trypsin
Why may the graph plateu of rate of reaction against substrate concentration
As over time, all enzyme active sites are used up –> Enzyme conc. is limiting factor
Why may the graph plateu of rate of reaction against enzyme conc.
As all substrate molecules have binded to active site –> Substrate conc. is limiting factor
What is end product inhibition
When the final product in a metabolic pathway inhibits enzyme earlier in a pathway
How does temp. affect active site
Increase K.E –> protein molecule vibrates
Ionic Bonds Break
Chnages in 3-D shape
Enzyme denatures
