Biochemistry Flashcards
Oxidoreductase
Catalyze oxidation-reduction reactions. Transfer of electrons between biological molecules.
Transferase
Catalyze the movement of a functional group form one molecule to another.
Hydrolase
Catalyze the breaking of a compound by adding water. (Hydrolysis)
Lyase
Catalyze a single molecule into 2 products.
Don’t require water as a substrate & don’t act as a oxidoreductase.
Isomerase
Catalyze the rearrangement of bonds within a molecule. Catalyze reactions between stereoisomers and constitutional isomers.
Ligase
Catalyze addition or synthesis reactions.
Between large similar molecules.
Require ATP
Enzyme Specificity
One enzyme will only catalyze one reaction or class of reaction.
if you use the word enzyme nothing will happen
Lock and Key Theory
Suggests enzyme’s active site (lock) is already the appropriate confirmation for the substrate (key)
Induced Fit
More commonly seen.
Substrate of changed to fit the active site
Cofactors
Inorganic molecules or metal ions. Typically ingested.
Coenzymes
Small organic groups
Mostly vitamins or vitamin derivatives: NAD+, FAD, Coenzyme A
Coenzyme B: water soluble vitamins
Coenzyme C: coenzymes that must be replenished because they are easily excreted (Fat soluble vitamins)
Michaelis-Menten rates
E + S <–> ES –>E+P
Michaelis-Menten equations
v= (v max)([S]) /Km + [S]
Turnover number (k cat)
v max = [E] k cat
Structural protein
collagen, elastin, keratin, actin, and tubulin
Motor protein
myosin, kinesin, dynein
Binding proteins
bind a specific substrate. either to sequester in the body or hold its concentration at steady state
Cell adhesion molecules (CAM)
Allows cells to bind to other cells or surfaces
Cadherins
calcium-dependent glycoproteins that hold similar cells together
Integrins
2 membrane-spanning chains and permit cells to adhere proteins in the extracellular matrix. some also have signaling capabilities.
Selectins
allows cells to adhere to carbohydrates on the surfaces to other cells and are most commonly used in the immune systems.
Ion channels
used for regulating ion flowing into or out of a cell.
Ungated channels
are always open
Voltage-gated channels
open within a range of membrane potentials
Ligand-gated channels
open in the presence of a specific binding substance, usually a hormone or neurotransmitter
Enzyme linked receptor
participate in cell signaling through extracurricular ligand binding and incantation of second messenger cascades.
G protein-coupled receptors
have a membrane bound protein associated with a generic G protein.
Electrophoresis
uses a gel matrix to observe the migration of proteins in response to an electric field
Native PAGE
maintains the protein’s shape, but results are difficult to compare because the mass-to-charge ratio differs for each protein
SDS-PAGE
denatures proteins and masks the native charge so that comparison of the size is more accurate, but the functional protein cannot be recaptured from the gel.
Isoelectric focusing
separates proteins by their isoelectric point the protein migrates toward an electrode until it reaches a region of the gel where PH=pI of protein.
Chromatography
separates protein mixtures on the basis of their affinity for a stationary phase or a mobile phase
