Enzyme regulation Flashcards
What are the 3 ways to regulate enzymes and what time frame do they work in?
Allosteric - seconds
Covalent modification - minutes
Hormonal - hours/days
How can glucose metabolism in skeletal muscle increase and decrease in a matter of seconds?
Allosteric regulation
What is allosteric control? (4)
Regulates the activity of a specific enzyme in a pathway
Regulates the rate limiting step
Allows for rapid changes in flux
Allosteric activators and inhibitors
What is the structure of an allosteric enzyme? (3)
Active site
Sites of allosteric activation
Sites of allosteric inhibition
What structure do all allosteric enzymes have?
Quaternary
What are the advantages of allosteric control? (3)
Selective - only specific enzymes are controlled
Flexible - adapts quickly
Sensitive - small changes important
What is covalent modification?
Involves addition/removal of phosphate groups
Switch enzyme to T or R state
What are the advantages of covalent control?
Rapid
Huge amplification
Often under hormonal control
