CH 2 Enzymes Flashcards
Oxidoreductases, for what type of reaction, what do they do?
Cofactor?
They catalyze oxidation-reduction rxns. The transfer of electron b/w biological molecules.
uses cofactors such as NAD+ and NADP+ that act as e- carriers
Transferases,
what does kinases do?
Catalyze the movement of a functional group from one molecule to another
Kinases are a type of transferases that transfers a phosphate group. Usually from ATP to another molecule
Hydrolases what and how do they catalyze?
give some examples:
what is a protease?
They catalyze the breaking of a compound into 2 molecules using the addition of water
i. e Phosphatase (protease): cleaves phosphate groups
peptidases: breaks down proteins
nucleases. .
lipases. .
Lyases what do they do
they catalyze cleavage of molecules into two products. without the use of water
they can also synthesis one molecules form 2. they are called synthases.
Isomerases what do they catalyze
They catalyze the arrangement of bonds within a molecule.
rxns b/w stereoisomers and constitutional isomers
LIgases
Catalyze addition or synthesis reactions, b/w larger similar molecules, and often require ATP
i.e in nucleic acid synthesis.
Cofactors and Coenzymes, what are the differences and types?
Fat soluble vitamins?
holoenzyme vs apoenzyme?
Prosthetic groups?
they are non-protein molecules that help in the rxns by carrying charge through ionization, protonation, or deprotonation.
Cofactors: inorganic molecules or metal ions, often ingested as dietary minerals.
Coenzymes: organic molecules i.e vitamins or derivatives such as NAD+, FAD, and Coenzyme A.
fat-soluble vitamins: ADEK (A DICK)
Holoenzyme: enzymes that use cofactors
Apoenzymes: enzyme do not use cofactors
Prosthetic groups: enzymes that need cofactors to function
Michaelis-Menten equation?
Km value and affinity
what does Km mean?
v= (vmax)([S]) / (Km + [S})
The Michaelis constant (KM) is the substrate concentration when the reaction rate (Velocity moles/sec) is at half of its maximal value (Vmax) (or in other words, it defines the substrate concentration when half of the active sites are occupied)
low Km value = high affinity for the enzyme
pH values in digestive tract?
stomach?
pancreatic enzymes in small intestine?
Stomach pH = 2
Pancreatic Enzymes pH = 8.5
Enzymatic irreversible inhibition tables
Uncompetitive: binds to allosteric site in enzyme-substrate complex and lock it and prevents its release. Km and Vm are decreased
MIxed: binds to allosteric site in either the enzyme (increased Km) or the enzyme-substrate complex (decrease Km = higher affinity locks it in place) Vm decreases in both cases
Enzymatic reversible inhibition
what is Kcat and catalytic efficiency?
