Enzyme Regulation Flashcards
Enzyme ___ is the ability of an enzyme to catalyze only one particular reaction
specificity
Specificity is due to the ____ ____ of enzyme and substrate
structural complementarity
The substrate glucose is bound to the active site of what enzyme?
hexokinase
What hypothesis considers that the enzyme’s active site is modified/flexible upon binding of the substrate?
induced fit
What hypothesis considers that the enzyme as the lock and the substrate fits in as the key?
lock and key
What are the four mechanisms of enzyme regulation?
genetic control, covalent modification, specialized controls , allosteric regulation
___ controls the amount of enzyme (gene induction of repression)
Genetic
____ ____ is the attachment of chemical groups such as phosphate groups
Covalent modification
Zymogens, isozymes, and modular proteins are examples of what?
Specialized controls
__ ___ is an inhibitor or activator binds to the enzyme at a site different than the active site.
Allosteric regulation
The phosphate groups are attached through the ___ side chains of amino acids, such as serine.
-OH
What donates the phosphate molecule in the attachment of a phosphate group via covalent modification?
ATP
The reversible covalent attachment of phosphate groups ____ enzyme actitivy
regulates
Protein ___ is an enzyme that adds a phosphate group to an enzyme
kinase
Protein __ is an enzyme that removes a phosphate group from an enzyme
phosphatase
Enzyme is catalytically inactive when the phosphate is ___
attached
Enzyme is catalytically active when the phosphate is ___
removed
The phosphate group addition affects protein __
folding
The __ ___ ___ is removed from the enzyme when adding a phosphate group
amino acid sidechain
Phosphate ___ the active site of an enzyme, making it inactive
closes
Attachment of phosphate groups can be ___
reversed
Zymogens are _____
proenzymes
___ are inactive precursors of enzymes or other proteins that acquire full activity by specific cleavage of one or more peptide bonds of the protein
Zymogens
Zymogens are ___ precursors of enzymes
inactive
Zymogens have ___ ____ of one or more peptide bonds of the protein
specific cleavage
Three examples of zymogens:
- Insulin
- Proteolytic enzymes
- Blood clotting factors
Insulin, proteolytic enzymes, and blood clotting factors are examples of ____
zymogens
Insulin is generated by ___ of a specific peptide from ____
removal, proinsulin
The activation of insulin is by the ___ of a specific peptide from the ___ ___ molecule.
removal, inactive proinsulin
Proteolytic enzymes of the ___ ___ are synthesized as zymogens in the pancreas and stomach
digestive tract
Blood clotting factors are produced by activation of zymogens of ___ ____ ___
blood clotting factors
____ are synthesized as zymogens in the pancreas and stomach
proteolytic
Activation of insulin by the ____ of a specific peptide from the ____ proinsulin molecule
removal, inactive
___ is a peptide hormone
insulin
Insulin is the active form of ___
proinsulin
Trypsin originates in the ___
pancreas
Chymotrypsin originates in the ___
pancreas
Carboxypeptidase originates in the __
pancreas
Elastase originates in the ___
pancreas
Pepsin originates in the ___
stomach !!
What is the active protein of trypsinogen?
trypsin
What is the active protein of chymotrypsinogen?
chymotrypsin