Enzyme Kinetics

I need help on how to approach this problem: What is the Km of an enzyme if, at [S] = 10^-3 M, 25% of the maximum velocity of the reaction is obtained? What is the ratio of substrate concentrations of a reaction proceeding at 90% and 10% of Vmax, respectively? ------- I know the basis of enzyme kinetics. I just don't ...continues

2 questions cannot get started

What is the amino acid sequence of the peptide? The complete hydrolysis of an unknown nonapeptide revealed the presence of Glu, Val, Val,Gly,Lys, Lys, Tyr, Thr and Phe residues. The first amino acid to be detected as a phenylthiohydantoin derivative on Edman degradation of the peptide was glutamic acid. The only amino acid de ...continues

Biochem

(See attached files for full problem description) --- 1. If the active site of a dipeptidase contains a glutamic acid residue (pKa 3.3) and a histidine residue (pKa 6.7), both of which must be charged for the substrate to bind, what is the optimal pH for substrate binding? 2. Lysozyme catalyzes the hydrolysis of C-O-C b ...continues

Attn: Stephen Allen (OTA#104330)

Evening Stephen, Thanks so much for checking my last sets of Protein Explorer Problems. I've got some bigger, more challenging molecules up on the screen this afternoon/tonight. Your guidance on working through the A through G problems has made for a really good foundation for these. I feel much more confident tracking t ...continues

aa pka problem

A solution with a mixture of 3 tripeptides is chromatographed on CM-cellulose at three different pHs: 6.0, 8.0, 10.0. I what order will each of the peptides emerge from the column at each of these pHs? pKa for CM-celluolse is 4.90 Please look at my attached chart and see if I calculated correctly. how will each emerge a ...continues

Enzymes &Carbohydrates

Explain the essential features of enzyme-substrate binding! Explain the factors that enable an enzyme to catalyze a reaction! Compare and contrast allostery with covalent modification. What is the same between these two mechanisms and what is different? Consider the following sugars: glucose, galactose, ribose an ...continues

enzyme kinetics for TA#104330 only please

for a MM reaction k1=5x10^7 k-1=2X10^4 k2=4x10^2 i calculated Km and Ks to be equal at about 4 x10^-4M Does substrate binding achieve equilibrium or the steady state? Also, you helped me with my table of amino acids....could you clarify when you have ph=pkA how you get whether it is -1/2 or +1/2 or in the other ...continues

Fate of Carbon in Glycolosis

Hey OTA's, This is the first in a series of some fun/challenging problem sets I am beginning the second half of the semester. I am approaching this problem on paper with the "colored pencil method" for following certain labelled carbon atoms (13C). I have done research online to find a clear representation of the cycle, and b ...continues

Release of C as CO2 in Glycoysis and TCA

Hey OTA'S, A second Glycolysis question. I have attached the problem with a web diagram for the TCA cycle. I have been using two text book representations to follow carbons with the colored pencil method. I have posted this to see if any of you guys are especially familiar with these two cycles and or following around 13 ...continues

Comparing efficiencies of glucose oxidation

Hello OTA's, This is a problem that asks for a comparison of relative efficiencies (ATP's per mole of glucose oxidized) for two different pathways. The answer can be simple and numeric. Any greater level of explanation would be awesome to see. After this example, I will be comparing these two pair of pathway in 9 diff ...continues