Enzyme IV - Regulation Flashcards
Metabolic enzymes are regulated by these four things?
Compartmentalization, Enzyme Concentration, Enzyme Activity, and Hormone Signals and Second Messengers
Substrate-level control acts on a?
Single reaction
Feedback control targets?
A different step in the pathway
Isozymes are known as the mix and match subunits? why?
They catalyze the same reaction but with different efficiencies.
LDH has __ isozymes?
5
What are reversible covalent modifications? what do post-translational modifications create?
Add 1+ functional groups to activate/inactivate the enzyme
Nonproteinogenic amino acid.
What are some common addititions in reversible covalent modifications for lipids? Nucleic acids? Proteins? Small molecules?
Lipids - Myristic acid and farnesyl
Nucleic acids - ADP-ribose
Proteins - Ubiquitin
Small molecules - y-carboxylation, sulfation, acetylation, methylation, Phosphorylation
Kinases _____ phosphates, Phosphatases ____ phosphates
Add, Remove
Allosteric binding does not occur where?
At the active site!
A. Heteroallostery
B. Homoallostery
___Effector binds at the allosteric site
___ Cooperativity
- A
2. B
ACTase is inhibited by?
CTP
CTP prefers the ___ state and ATP prefers the ___ state
inactive (t); acitive (r)
Protein synthesis regulation functions as a?
ON/OFF switch.
Histone acetylation ___ transcription; Histone phosphorylation ___ transcription
Promotes; Prevents
** Methylation can do either**
Euchromatin is on/off, and heterochromatin is on/off
On; Off
