Equations For Biochemistry (Amino Acids, Peptides, and Proteins)

University:
York University
Course:
BIOL 2020 | Biochemistry
Academic year:

2023
Views:

23

Pages:

3
Author:

esfredint7qo

Equations Biochemistry Section Amino Acids, Peptides, and Proteins Equation Name Isoelectric point (pI) Equation pI neutral aa= p K a , NH +¿group 3 Use / Description + p K a , COOH group 2 ¿ p K a, R group + p K a , COOH group pI acidic aa= 2 pI basicaa = Enzymes Michaelis-Menten rates Michaelis-Menten equation p K a , NH + ¿group 3 + p K a , R group 2 k1 E+ S ⇌ ES k cat E+P → k −1 v= v max [S ] K m+[ S ] ¿ pI = the pH at which the molecule is electrically neutral Aa’s with non-ionizable side chains have pI around 6 Aa’s with acidic side chains have relatively low isoelectric points (well below 6) Aa’s with basic side chains have relatively high isoelectric points (well above 6) k1 = rate E-S complexes forms k-1 = rate E-S complexes dissociate kcat = rate E-S complex turns into E + P v = velocity of enzyme vmax = maximum enzyme velocity Km = Michaelis constant (the [S] at which ½ E’s active sites are full) Turnover number (kcat) v max=[E ]k cat vmax = maximum enzyme velocity kcat = # of S molecules “turned over” (converted to product) Catalytic efÏciency k cat Km kcat = # of S molecules “turned over” (converted to product) Km = Michaelis constant (the [S] at which ½ E’s active sites are full) Nonenzymatic Protein Function & Protein Analysis Migration velocity Carbohydrate Structure & Function # possible stereoisomers of a compound Number of stereoisomers withcommon backbone=2 Osmotic pressure (P) Π=ℑ R T Biological Membranes Nernst equation Bioenergetics & Regulation of Metabolism v= E= [ion]outside R T [ion]outside 61.5 ln log = z F [ion]inside z [ion] inside Goldman-HodgkinKatz voltage equation V m =61.5 log ¿ Gibbs Free Energy (DG) ∆ G=∆ H −T ∆ S Modified Standard State ' v = migration velocity of a molecule E = electric field strength z = net charge on the molecule f = frictional coefÏcient Ez f ∆ G=∆ G ° + R T ln(Q) n n = # of chiral Cs in the molecule (of a solution) i = van’t Hoff factor 9the # of particles obtained from a molecule when in solution) M = the molarity of the solution R = the ideal gas constant T = the absolute temperature (kelvins) Used to determine the membrane potential (Vm) from the intra- & extracellular concentrations of various ions. R = the ideal gas constant T = the temperature (kelvins; assumed to be 310 K for body temp in simplified equation) z = the charge of the ion F = the Faraday constant (96,485 C/mol e-) Flows from the Nernst equation, taking into account the relative contribution of each major ion to the membrane potential. DH = Enthalpy T = Temperature DS = Entropy DG°’ = Modified standard free energy R = the universal gas constant T = the temperature Q = the reaction quotient Respiratory quotient (RG) Body mass index (BMI) RQ= CO2 produced O2 consumed BMI= mass 2 height …for the complete combustion of a given fuel source (e.g., carbohydrates). Mass = kg Height = m Normal BMI = 18.5 – 25 Underweight = below 18.5 Overweight = 25 – 30 Obese = above 30