Introduction to Enzyme Kinetics Introduction to Enzyme Kinetics The purpose of this experiment is to measure the rates of reaction of the enzyme Alkaline Phosphatase with the substrate p-nitrophenol phosphate under varying conditions. The concentration of both substrate and enzyme were diluted and the inhibitor vanadate was utilized to determine whether or not the reaction is substrate or enzyme dependent and to see what type of inhibition vanadate was involved. A class of proteins called enzymes catalyzes almost every chemical reaction in a cell. Enzymes increase the rates of reaction for those reactions, which are already energetically favorable, by lowering the activation energy.
Cytochrome P (P, CYP) research provides many opportunities for the application of kinetic isotope effect (KIE) strategies. Ps collectively catalyze oxidations of more substrates than any other group of enzymes, and C H bond cleavage is a major feature in a large fraction of these reactions. Ask a friend to read your introduction and then tell you what he or she expects the paper will discuss, what kinds of evidence the paper will use, and what the tone of the paper will be. If your friend is able to predict the rest of your paper accurately, you probably have a good introduction. Research needs and requirements vary with each assignment, project or paper. Although there is no single "right" way to conduct research, certain methods and skills can make your research efforts more efficient and effective.
For human in vivo considerations the TCAs are grouped as pairs i. Clomipramine is the most potent, and the only available drug with combined affinities for both systems of less than one.
It is unlikely that varying drug levels in different tissues would compensate for the extreme weakness of venlafaxine and desvenlafaxine as an NRIs. There is one further observation concerning the superior efficacy of clomipramine that I made many years ago, and for which I have never seen a satisfactory alternative explanation that would contradict my view.
If the number of people who take an overdose not the number of deaths from ODfor every hundred thousand scripts issued, is very substantially less for one particular drug then one obvious explanation is that the drug is a more effective antidepressant and greatly reduces suicidal urges: One different explanation of this that I recall being proffered in the past was that it was because clomipramine was used for obsessive-compulsive disorder, and such patients attempted suicide much less frequently than those with depression.
That is probably true, but OCD is such a rare disease as a primary disorder in the absence of depression that the number of such patients represented in the clomipramine sample would be very small indeed compared to the total number of patients to whom scripts had been issued.
It is obvious that could not possibly account for a difference in the attempted suicide rate that is around ten-fold.
The most parsimonious explanation is that if you take clomipramine you are far less likely to feel suicidal and act on that feeling: Estimated median effective dose ED50 of clomipramine hydrochloride was 2.
SERT occupancy in humans: Some studies suggest no difference at all Paradoxically, for older patients any possible differences may be smaller. A key consideration which can sometimes be lost in this market-orientated side-effects debate is that a drug with less side-effects or lower toxicity in over-dose is not an advance if it is less effective.
In my view, this sums up the position of many new drugs, including SSRIs, which are less effective for serious depression.
The problem is not death caused by the toxicity of prescribed anti-depressant drugs when taken as an overdose.
If patients get better from the depression they are less likely to commit suicide. The comparatively much lesser problem of the potential toxicity of drugs in overdose and claimed differences between various drugs is appropriately dealt with by good clinical management of any seriously ill patients.
Choosing a marginally less toxic-in-overdose drug is not the first-stop option. Good clinical management involves seeing them more frequently and not prescribing potentially fatal quantities of drugs.
All studies show that drugs generally, whether prescribed or not, whether anti-depressants or not, make a minor contribution to the number of deaths from suicide in those suffering serious depression It is a good scare tactic and sales pitch though — how could I even think that!
In other words, the likely degree of error in the data is greater than the differences being pontificated about. A novel form of ambulance chasing! For clomipramine it is around 12 per million, nortriptyline is around 5 per million, venlafaxine is around 13 per million.
Initial Dose and Rate of Dose Increase Providing the dose of clomipramine is adjusted carefully it is tolerated well by most patients; blood levels of all TCAs are often useful in optimising the dose 59, 60although it is a little surprising that many psychiatrists never measure them e.Cytochrome P (P, CYP) research provides many opportunities for the application of kinetic isotope effect (KIE) strategies.
Ps collectively catalyze oxidations of more substrates than any other group of enzymes, and C H bond cleavage is a major feature in a large fraction of these reactions. Search results for CYP at Sigma-Aldrich. Compare Products: Select up to 4 products.
*Please select more than one item to compare. Introduction: 50 th Birthday Tribute. Clomipramine is usually thought of by doctors as a treatment for obsessive-compulsive disorder (OCD).
But it is a potent antidepressant with dual SNRI action (see tables of comparative receptor affinity data below).
Introduction to Enzyme Kinetics Cytochrome P Cytochrome P (CYP or P) is the term used for a sizeable quantity of oxidative enzymes that are evolutionarily related. Charter School Rates of Attrition and Paper Introduction.
which appear to be much higher in charter schools. Making Practical Sense of Cytochrome P Guidelines for the likely 20 to 30% of pain patients who have a genetic defect involving one of three major CYP enzymes and so cannot effectively metabolize certain opioids that must be converted to a metabolite to be effective.
CYP Understand the main legislation, guidelines, policies and procedures for safeguarding children and young people Outline current legislation, guidelines, policies and procedures within own UK Home Nation affecting the safeguarding of children and young people.