Download Video Enzymes (Part 3 Of 5) - Lineweaver Burk Plot - Double Reciprocal Plot 1080p 720p 480p MP4 FLV 3GP MP3, Download LaguEnzymes (Part 3 Of 5) - Lineweaver Burk Plot - Double Reciprocal Plot Lengkap Terbaru
TY - JOUR. T1 - Protein coordination to manganese determines the high catalytic rate of dimanganese catalases. Comparison to functional catalase mimics. AU - Shank, Mary. AU - Barynin, Vladimir. AU - Dismukes, G Charles. PY - 1994. Y1 - 1994. N2 - Catalysis of hydrogen peroxide dismutation by the dimanganese catalase from Thermus thermophilus has been measured and found to obey Michaelis-Menton kinetics with no evidence for substrate inhibition at concentrations up to 0.45 M H2O2. Comparison among three dimanganese catalases (Thermus thermophilus. Thermoleophilium album, and Lactobacillus plantarum) reveals that their apparent second-order rate constants, kcat/Km, differ by at most a factor of 5, even though the individual kinetic constants differ by as much as a factor of 20. This similarity suggests that all three enzymes may have the same rate-determining step. For T. thermophilus catalase we find that kcat/Km ∼ kbi, the bimolecular rate constant at limiting substrate concentrations. Thus, ...
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Due to their long lifetime, triplet, redox and other transient states of fluorophores are highly sensitive to the micro-environment. Imaging their spatial distribution in biological samples can therefore help answer interesting questions about the metabolism, molecular interactions and dynamics in living cells. However, as these states are at best weakly luminescent, they have up to now only been used to a limited extent in life sciences. In Transient State (TRAST) imaging, the characteristic build up of transient states is instead monitored via fluorescence, as the excitation is modulated. When the illumination pulse width is step-wise increased, transient states are progressively populated. The resulting depletion of the singlet excited state can be monitored via time-averaged fluorescence. This fluorescence decay is characteristic for the transient state kinetics of the fluorophore in a given environment. Traditional fluorescence parameters can only be influenced within the lifetime of the ...
Ligand uptake and release by the haemoglobin contained within adult mouse erythrocytes was studied by using dual-wavelength stopped-flow techniques. The rate of O2 uptake is very much lower than that expected for an equivalent concentration of haemoglobin in free solution. The O2-concentration-dependence found in uptake experiments is greater than first-order. CO uptake shows the same pattern of reactivity as does O2, but the associated rates of uptake are lower and the concentration-dependence of the CO rates is first-order. O2 release from the adult erythrocytes was measured by stopped-flow mixing with Na2S2O4. Under these circumstances the deoxygenation of intracellular haemoglobin shows accelerating time courses. The apparent rate-constant-dependence on dithionite concentration shows a rate limit at high reductant concentrations. Computer simulations of both ligand uptake and release processes were carried out by using a three-dimensional model. The simulations clearly indicate that in ...
Synonyms for Ping Pong Bone in Free Thesaurus. Antonyms for Ping Pong Bone. 16 synonyms for bone: cram, grind, os, osseous tissue, off-white, pearl, ivory, bone up, grind away, mug up, swot, swot up, cram, drum, get up, debone. What are synonyms for Ping Pong Bone?
where first term is the rate of dissapearance of substrate S and second term is the rate of appearance of product P (both S and P are in concentration).. Behavior of Initial Rates. The initial rate (Vo) is determined by extrapolating the slope of the time course of the substrate or product concentration to time zero (Fig. 3.5). The dependence of Vo on the substrate concentration, S (at constant enzyme concentration), is shown in Fig. 3.6. It reflects the typical substrate saturation. At first, Vo increases proportionally to the amount of substrate. Upon further enhancement of substrate concentration Vo levels off. The curve asymptotically approaches a maximum value, Vmax. When this plateau is reached, a change of S does not lead to a measurable change of Vo: the enzyme is saturated by substrate and has thus reached the limit of its efficiency.. Micahaelis-Menten Kinetics. These kinetics result from the fast and reversible formation of an enzyme-substrate complex, ES, which dissociates in a ...
If the kinetic data for an inhibitor do not match any of the above patterns, the inhibitor may act in a mode referred to as mixed inhibition. In this scenario, the inhibitor can bind to both E and ES, but with different affinities. In this case, there are two Kis (one for the dissociation of EI and one for the dissociation of ESI) that are related to each other by a variable, α. In cases of mixed inhibition, the Km is usually increased and the Vmax is usually decreased in comparison to the values for the uninhibited reaction. A typical Lineweaver-Burk plot for mixed inhibition is shown on the right below. It is not possible to calculate a Ki value for this type of inhibition with the data gathered in this lab. If you think your data suggest a mixed inhibition mechanism, you should determine with which of the other modes of inhibition they are most consistent and use that formula to calculate a Ki value. Notice that, when the variable α is very large, the mechanism of inhibition approaches ...
A continuous-flow apparatus is described for automatically plotting substrate saturation curves, and is suitable for use with a variety of enzymes. A linear concentration gradient of the variable substrate is combined with a fixed proportion of the other substrates and the enzyme, and after passing through a reaction coil the product concentrations are measured spectrophotometrically. Use of a 4cm. flow cell and modified spectrophotometer permits accurate measurement of NADH concentration in the region of 0·1μm. Precise control over reaction times and substrate concentration is achieved by using power-driven syringes with an integral mixer. Specimen results are given for yeast alcohol dehydrogenase.. ...
1FKG: DESIGN, SYNTHESIS, AND KINETIC EVALUATION OF HIGH-AFFINITY FKBP LIGANDS, AND THE X-RAY CRYSTAL STRUCTURES OF THEIR COMPLEXES WITH FKBP12
... by Blas Uberuaga Los Alamos National Laboratory Materials Science and Technology Division
Subjects were randomised to one of three possible dose levels (low, middle or high) and to one of two treatment sequences. A treatment sequence consisted of 2 periods of each 13 days. One dose once daily. The trial products were administered subcutaneously (under the skin ...
When suspensions involving rigid rods become too concentrated, standard dilute theories fail to describe their behavior. Rich microstructures involving complex clusters are observed, and no model allows describing its kinematics and rheological effects. In previous works the authors propose a first attempt to describe such clusters from a micromechanical model, but neither its validity nor the rheological effects were addressed. Later, authors applied this model for fitting the rheological measurements in concentrated suspensions of carbon nanotubes (CNTs) by assuming a rheo-thinning behavior at the constitutive law level. However, three major issues were never addressed until now: (i) the validation of the micromechanical model by direct numerical simulation; (ii) the establishment of a general enough multi-scale kinetic theory description, taking into account interaction, diffusion and elastic effects; and (iii) proposing a numerical technique able to solve the kinetic theory description. This paper
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The biological sciences have a uniquely intertwined yet strangely dysfunctional relationship with the bioinformatics and visualization sciences. Bio/Life Sciences researchers and practitioners regularly rely on visualization techniques for solving a large range of problems, including use of charts, graphs and interactive displays. They frequently prefer these visualization techniques to analytical techniques, methods of a computational and/or statistical nature, even when the analytical techniques produce more accurate results. For example every biochemistry student knows how to calculate rate constants for Michaelis-Menten [1] enzyme kinetics based on extracting the slope and intercept from a hand fitted double reciprocal Lineweaver-Burk plot [2]. Despite years of understanding that the double reciprocal plot distorts errors, making accurate hand fitting of the data almost impossible [3], this and other problematic graphical linearizations are still in use. At the same time, most students would ...
Kinetic Features of PCDD Adsorption in Carbon Beds, Vincenzo Piemonte, Mauro Capocelli, Marina Prisciandaro, In this paper, starting from the knowledge of thermodynamic parameters, the adsorption of toxic dioxins is studied in the conditions typically en
MCLAUGHLIN, K., BERTOLUCCI, C., PIERSON, S., LATHAM, D. (1990). Fundamental Chemical Kinetics Study of Cayalytic Polymerizations: Influence of Reaction Mechanism on Product Distribution for Ziegler-Natta Catalysis. Abstracts of Papers of the American Chemical Society, 200, 228-POLY ...
A possible physiological role of the Na+/Ca2+ exchange mechanism ofbrown-fat mitochondria in the mediation of alpha 1-adrenergic signals. ...
Start to kinetics experiment from the second window and type multi_zgvd to start acquisition. This command will start the acquisition and ask you for a) the number of spectra, b)?? and c)??. Each of your spectra will be recorded in a diffent window using consecutive filenames. Keep in mind that you can accumulate huge amounts of data in this type of experiment ...
BGs often show a complex kinetics, including inhibitory effects of substrate and activating effects of inhibitors. The substrate inhibition caused by the competing hydrolysis and transglycosylation to substrate reactions is well recognized [8-10]. This type of substrate inhibition is easily detected because of the breakdown of Michaelis-Menten saturation kinetics. Another inhibitory effect of substrate can be seen in nonproductive binding, which competes with the productive binding of substrate. Since, in this case, the Michaelis-Menten saturation kinetics holds, the effects of nonproductive binding are often overlooked. A kinetic peculiarity of many BGs is the activation of enzyme by inhibitor at low-to-moderate concentrations followed by inhibition at high concentrations. The most common explanation to this phenomenon is the transglycosylation to inhibitor, and, indeed, in many cases, the transglycosylation products are observed in reactions containing inhibitor [19, 26]. However, the ...
Looking for bimolecular reaction? Find out information about bimolecular reaction. A chemical transformation or change involving two molecules Explanation of bimolecular reaction
Can carry out several experiments and measure the initial rate, keeping the concentration of one of the reactants constant.. Or can carry out the experiment with an excess amount of the reactant so that over the course of the experiment, its concentration does not change significantly.. The progress curve method. Shows how the concentration of a reactant/product changes as the reaction proceeds.. Draw tangents to the curve at particular concentrations , gradient gives rate of reaction for that concentration , then find the order with the initial rates method.. Initial rates method: draw tangents at the origin of different progress curves , then draw graph of intial rates against concentration.. , Straight line = first order reaction. , If graph of intial rate against (concentration)² is a straight line = second order reaction. , If rate does not change with changing concentration = zero order reaction. ...
The minimum energy required to carry out the reaction is called the energy of activation, Ea. If a reaction requires higher activation energy, the rate of reaction is lowered. The presence of a catalyst lowers the activation energy and increases the rate of reaction. In biological systems, enzymes act as catalysts. Arrhenius equation. 3RT2T1 k2 Ea = ________ log ___ T2 - T1 k1 where k2 and k1 are the specific reaction rate constants at two different temperatures, T2 and T1, respectively. The effect of temperature on the rate of reaction is frequently expressed in terms of a temperature coefficient, Q10, which is the factor by which the rate of reaction increases when the temperature is raised by 10°C. 6 BIOCHEMICAL KINETICS The concentration of the enzyme-substrate complex influences the velocity of enzymatic reactions. The relationship between the velocity of a reaction and the concentration of substrates is described by the Michaelis-Menton equation: Vm[S] v = _________ Km + [S] where v is ...
Bistability (coexistence of two stable steady states in a dynamical system) is a key mechanism of cellular decision-making and has been observed in many biochemical reaction networks such as mitogen-activated protein kinase (MAPK) signaling pathways. Theoretical studies have shown that bistability can arise in a single two-site MAPK phosphorylation and dephosphorylation cycle. However, the bistable behavior mostly relies on the kinetic mechanisms and parameters of this two-site modification. In exploring the system-level properties of MAPK regulation, most models to date focus on two limiting reaction regimes, distributive and processive, and are characterized by high levels of parametric uncertainty. Here, we developed a combined kinetic method which applies a continuous spectrophotometric enzyme-coupled assay incorporated with the viscosity approach, to perform detailed kinetic analyses of p38α MAPK dual phosphorylation by MKK6. Almost all kinetic rate constants for the first and second ...
View Notes - prexam2 from PHY 206 at University of Miami. case. b) The partition is removed and the gases mix and reach equilibrium. Taking the molar heat capacity of the gas to be C (i.e. with units
Sequence requirements of the ATP-binding site within the C-terminal nucleotide-binding domain (NBD2) of mouse P-glycoprotein were investigated by using two recombinantly expressed soluble proteins of different lengths and photoactive ATP analogues, 8-azidoadenosine triphosphate (8N(3)-ATP) and 2,3,4-O-(2,4,6-trinitrophenyl)-8-azidoadenosine triphosphate (TNP-8N(3)-ATP). The two proteins, Thr(1044)-Thr(1224) (NBD2(short)) and Lys(1025)-Ser(1276) (NBD2(long)), both incorporated the four consensus sequences of ABC (ATP-binding cassette) transporters, Walker A and B motifs, the Q-loop, and the ABC signature, while differing in N-terminal and C-terminal extensions. Radioactive photolabeling of both proteins was characterized by hyperbolic dependence on nucleotide concentration and high-affinity binding with K(0.5)(8N(3)-ATP) = 36-37 microM and K(0.5)(TNP-8N(3)-ATP) = 0.8-2.6 microM and was maximal at acidic pH. Photolabeling was strongly inhibited by TNP-ATP (K(D) = 0.1-5 microM) and ATP (K(D) = 0.5-2.7
Ensemble and reduced-rank approaches to prediction and assimilation rely on low-dimensional approximations of the estimation error covariances. Here stability properties of the forecast/analysis cycle for linear, time-independent systems are used to identify factors that cause the steady-state analysis error covariance to admit a low-dimensional representation. A useful measure of forecast/analysis cycle stability is the bound matrix, a function of the dynamics, observation operator and assimilation method. Upper and lower estimates for the steady-state analysis error covariance matrix eigenvalues are derived from the bound matrix. The estimates generalize to time-dependent systems. If much of the steady-state analysis error variance is due to a few dominant modes, the leading eigenvectors of the bound matrix approximate those of the steady-state analysis error covariance matrix. The analytical results are illustrated in two numerical examples where the Kalman filter is carried to steady state. ...
Biology Assignment Help, Reaction - processes in succession, Reaction - Processes in Succession This is the most important stage in succession. The mechanism of modification of environment, through the influence of living organisms on it is known as reaction. As a result of reaction, changes take place in
Inhibitory Properties of YM-244769. We first compared the inhibitory effects of YM-244769 on Nai+-dependent 45Ca2+ uptake (i.e., reverse mode) into CCL39 cells with a stable transfection of NCX1, NCX2, or NCX3. YM-244769 (0.003-1 μM) inhibited dose dependently the initial rates of 45Ca2+ uptake into NCX1, NCX2, and NCX3 transfectants with IC50 values of 68 ± 2.9, 96 ± 3.5, and 18 ± 1.0 nM (n = 4), respectively (Fig. 2), indicating that YM-244769 is approximately four to five times more selective to NCX3 than other isoforms. In NCX3 transfectants, YM-244769 was more than 80 times more inhibitory than KB-R7943 [IC50 = 1.5 μM, as reported previously (Iwamoto and Shigekawa, 1998)]. To check whether YM-244769 competes with Ca2+o for the exchanger, the rate of Nai+-dependent 45Ca2+ uptake into NCX1 transfectants was measured under standard conditions as a function of Ca2+o concentration (0.06-2 mM) in the presence or absence of 0.05 μM YM-244769. Their double reciprocal plots of uptake rate ...
Pre-steady state kinetics involve measuring of the formation of the enzyme/substrate complex. A stopped flow accessory can be added to the majority of these instruments. Other accessories include the TLC 50, Four cell Peltier turrets, and the Automated Enzyme Assay Device. The Olis CLARiTY chamber offers an exciting new possibility of measuring enzyme kinetics in highly scattering environments such as those in whole cell or mitochondria suspensions.. ...
Inducing gene expression from an all-or-none promoter at subsaturating inducer concentrations results in a heterogeneous population of cells in which some are fully induced and others are induced very little, if at all. What is often confusing about this phenomenon in practice is that a population of cells will typically respond in a linear manner to increased concentration of inducer. What is really happening, though, is that more cells in the population are being turned on as inducer concentration is increased, but there are still some cells in the population that are not induced at all. The on phenotype is a result of inducer importers being turned on when a cell is exposed to the inducer, resulting in increased uptake of the inducer. At subsaturating inducer concentrations, there is not enough inducer to go around for all of the cells, so those that get their importer turned on first get all of the the inducer ...
Question:A second-order reaction 2A → B is taking place in a gas phase. The initial pressure in the system is P0 (compound B is absent). Find the overall pressure as a function of time. After what time the total pressure will decrease 1.5 times with respect to the initial pressure? What is a degree of completion of the
Many inhibitors affect enzyme activity • Competitive inhibition - inhibitor competes for the active sites on enzyme with the substrate • Non-competitive inhibition - inhibitor binds to an allosteric site and alters the active site configuration of the enzyme • Feedback inhibition - enzyme activity is inhibited by the end product (A enzyme-1 B enzyme-2 C enzyme-3 D) - here enzyme-1 may be inhibited by product D • Feedback inhibition regulates ATP, amino acid, numcleotide and vitamin synthesis Mechanism of enzyme action • Substrate specifically binds to the active site on the surface of the enzyme and as a consequence enzyme-substrate complex is formed - can result in change of structure of the enzyme • Substrate is transformed into product by - Rearrangement of existing atoms - Breakdown of substrate molecules - Combining with other substrate molecules • Resultant products do not fit the active site and thus are released and the enzyme site becomes free for ...
In my opinion, [tex]\frac{d[ES]}{dt}[/tex] means the rate of change of the concentration of the enzyme-substrate complex with time. Thats it. Not the formation, but actually any factor that contributes to the change in ES concentration should be considered in this equation. I dont understand the negative derivative; to me, it says simply the negative of the change in ES concentration. It doesnt even seem to be possible to argue that the textbook is saying that the rate of breakdown is equal in magnitude but opposite in sign to the rate of formation, because, although this is true under steady state conditions, the notation ITSELF doesnt make sense, AND the notation is supposed to extend beyond these conditions (hence why it is used to say that WHEN d[ES]/dt = -d[ES]/dt, then steady state is achieved; which, as I say, doesnt even seem to make sense ...
Voltage clamp experiments were done on single nodes of Ranvier to study the inhibition of the sodium permeability by tetrodotoxin (TTX). Equilibrium results could be excellently fitted on the assumption that a sodium channel is blocked when one toxin molecule binds to it, the equilibrium dissociation constant, KT of this reaction being 3.6 nM at 20 °G. Onset and offset of block could be quantitatively interpreted to be determined by the rates of the TTX-channel reaction whose average constants, at room temperature, were 3 x 106 m-1 s-1 for the association (k1) and 1.4 x 10-2 s-1for the dissociation (k2). The dependence of the constants on temperature could be described by Arrhenius plots yielding activation energies of 29.3, 85.5 and 41.0 (57.3) kJ/mol for KT, k2 and k1 (k1 derived from onset alone), respectively. At low pH the relative TTX effect was clearly less than at neutral pH. These results could be explained by a model involving the competition of TTX and protons for the samereceptor ...
View Notes - 11 from CHE 321 at SUNY Stony Brook. 9/27/2011 What is the second product of the following reaction? ΞC-H -C-H =C-H O-H (s) CO2H N-H 4000 CΞC C=C C=O(s) What is the best structure that
The mass transfer kinetics of thiourea, phenol, ethylbenzene, propylbenzene, butylbenzene, and amylbenzene were studied on a Gemini-C18 (5 μm, 110 A˚, 375 m2/g) column (150 mm × 4.6 mm) eluted with methanol/water solutions (100, 90, and 20% v/v). Each of the successive steps of the mass transfer of these solutes (axial diffusion, eddy dispersion, film mass transfer resistance, and transparticle mass transfer resistance) was unambiguously measured, using a combination of the peak parking method, the total pore blocking method, and moment analysis, in a wide range of reduced linear velocities. The results obtained offer new insights on the mass transfer kinetics in chromatographic columns. They show first that the eddy dispersion A-term is strongly correlated with the particle porosity. The complex, anastomosed transcolumn flow pattern causes extra band broadening. This transcolumn effect was found to be markedly smaller with porous particles than with nonporous particles of the same size. ...
Solution for question: Sucrose decomposes in acid solution to give glucose and fructose according to the first order rate law. The half life of the reaction is 3 hours. Calculate fraction of sucrose which will remain after 8 hours concept: Integrated Rate Equations - Half-life of a Reaction. For the courses CBSE (Arts), CBSE (Commerce), CBSE (Science), HSC Science (Computer Science), HSC Science (Electronics), PUC Karnataka Science
Not long ago in thw sci.chem group Phillipe Schmitt (Chemistry Dept., Oxford Univ.) asked about complex kinetics. In particular, how could one distinguish most quickly between several possible molecular mechanisms such as A + B ,==, C and A + B ,==, C* ,==, C based on available experimental data, following the formation of C over time? There has been a lively discussion on the subject. Now we have used the program DYNAFIT (Analytical Biochemistry vol. 237, pp. 260-273) successfully to discriminate between these mechanisms, and two more: D ,==, A + B ,==, C and A + B ,==, C A + D ,==, E . The advantage of DYNAFIT is that the program derives automatically the underlying rate equations from a symbolic input such as [mechanism] A + B ,==, C* : k1 k2 C* ,==, C : k3 k4 so that going through two, or four, or fifteen reaction mechanisms can be done in the matter of minutes regardless of whether the integral equations can be derived in principle. The results of this particular study are quite ...
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Thus, when a great deal of substrate is altered by an enzyme every minute, the reaction is said to be proceeding at a rapid rate.. In enzyme reaction rates, the rate depends on the CONCENTRATION of the enzyme and the CONCENTRATION of the substrate (CONCENTRATION rather than AMOUNT). Concentration refers to amount in a given volume of solution. As previously mentioned, it has been calculated that enzyme mediated reactions occur 1 x 109 times faster than the same reactions without enzymes.. In most enzyme reactions, enzyme concentration is small compared to the substrate concentration. Therefore, the rate of the reaction becomes proportional to the concentration of the enzyme. If the enzyme concentration is doubled, the reaction rate is doubled. At low substrate concentrations, the rate of the reaction is proportional to the substrate concentration, but at higher substrate concentrations the reaction rate is independent of substrate concentration. That is, further increase in the amount of ...
Applying the Arrhenius equation, rate constant and half-life of the substance were calculated at 20 °C and pH 4, pH 7 and pH 9. The ln-transformed data of rate constants at the three temperatures of the hydrolysis test were plotted against 1/T (T= t+273.15 °C). The lines were fitted on the data and the rate constants at 20 °C were calculated from the constants and slopes (x coefficient) of regression lines. The final results are the following: pH value t1/2, min 4 18 7 7 9 0.32 The substance was highly unstable with a half-life in the order of minutes under test conditions. Instability increased as temperature and pH increased. ...
The electron transfer catalysed by POR follows the pathway: NADPH → FAD → FMN → acceptor (Figure 4A), with FMNH2 being the form that transfers electrons to the acceptor proteins [35]. Rapid mixing of POR with NADPH in the stopped-flow instrument under anaerobic single-turnover conditions allows one to discern the steps involved in the half-reaction of POR reduction by NADPH. POR and NADPH solutions (in 1:1 or molar ratios) were rapidly mixed from separate syringes and changes in A450 and A590 were monitored. Decay of the A450 signal reflects NADPH reduction in flavin, which includes FAD reduction and, to a lesser extent, FMN reduction (i.e. electron transfer from FADH2 to FMN to yield FADH•/FMNH• and FAD/FMNH2 forms) (Figures 4B and 4C). The increase in the A590 signal reflects the formation of the blue disemiquione FADH•/FMNH• complex (Figures 4D and 4E). This reaction for WT POR has been studied extensively, mostly using soluble forms of POR that cannot support reactions in ...
a) Histogram of the second-order rate constants determined after 60 minutes from the initiation of the reaction; b) histogram of the second-order rate constants
TY - CHAP. T1 - Kinetics of Bio-Reactions. AU - Villadsen, John. PY - 2015. Y1 - 2015. N2 - his chapter predicts the specific rates of reaction by means of a mathematical expression, the kinetics of the reaction. This expression can be derived through a mechanistic interpretation of an enzymatically catalyzed reaction, but it is essentially of empirical nature for cell reactions. The models can be used in mass balances for design of processes under process conditions not yet studied experimentally. The value of the predictive kinetic model depends on the quality of the experimental data on which the model is based, and well-founded kinetic models for enzyme reactions have a considerable predictive power. This is also true for cell reaction models, when the model is used in its proper context. The chapter first discusses the kinetics for enzymatically catalyzed reactions ("enzyme reactions"). The kinetics can be derived from a mechanistic model. Then, the chapter derives empirical expressions for ...
pdoyle at medsun.unige.ch (Patrick Doyle) writes: I am interested in talking with anyone or specific groups that are looking at insulin and its related effects on brain glucose metabolism.In particular brain region specific effects are of most interest as I have results showing that insulin after given to rats for 4 days in steady state conditions causes area related effects in areas such as the locus coeruleus and the dentate gyrus.Has anyone knowledge of a good reference point or raw data of possible connections between these areas? There is quite a strong projection from the L.C. to the dentate gyrus. A good general reference for all such matters is the following: @InCollection{swanson87, author = L. W. Swanson and C. Kohler and A. Bjorklund, title = The Limbic region. {I}: The septohippocampal system, booktitle = Handbook of Chemical Neuroanatomy, publisher = Elsevier, year = 1987, editor = A Bjorklund and T. Hokfelt and L. W. Swanson, volume = 5, chapter = II, pages = 125--277 ...
5. The initial rate of a first order reaction is 5.2 x 10-6 mol lit-1 s-1 at 298 K, when the initial concentration of the reactant is 2.6 x 10-3 mol lit-1. Calculate the first order rate constant of the reaction at the same temperature. ...
In the present study we have observed that passive transfer of 16/6-Id antibodies directly to mice brains resulted in a selective cognitive impairment, expressed as visual recognition and spatial memory deficits. Depressive behavior (FST) and locomotor activity (staircase test) were not altered in the 16/6-Id injected mice, when compared to the control group. Our findings suggest that 16/6-Id antibodies may have a role in the pathogenesis of cognitive impairment observed in some patients with SLE [8].. Immunostaining of brain sections from both groups revealed increased presence of activated microglia and astrocytes, in the hippocampal region of the 16/6-Id injected mice, compared to the controls. The hippocampus has an important function in memory processing, therefore, its damage by an inflammatory processes may affect cognitive performance in the 16/6-Id injected mice. Astrocytes in steady state conditions are mainly responsible for biochemical support and several other chemical roles such as ...
JILA is a joint physics institute of the University of Colorado at Boulder and the National Institute of Standards and Technology. We support an eclectic and innovative research program that fosters creative collaborations among our scientists. Collaborations play a key role in the pioneering research JILA and the JILA Physics Frontier Center are known for around the world. To learn more, visit our About JILA page.. ...
In order to identify the forces involved in the binding and to understand the mechanism involved, equilibrium and kinetic studies were performed on the binding of the winged bean acidic lectin to human erythrocytes. The magnitudes of delta S and delta H were positive and negative respectively, an observation differing markedly from the lectin-simple sugar interactions where delta S and delta H are generally negative. Analysis of the sign and magnitudes of these values indicate that ionic and hydrogen bonded interactions prevail over hydrophobic interactions resulting in net -ve delta H (-37.12 kJ.mol-1) and +ve delta S (14.4 J.mole-1 K-1 at 20 degrees C), thereby suggesting that this entropy driven reaction also reflects conformational changes in the lectin and/or the receptor. Presence of two kinds of receptors for WBA II on erythrocytes, as observed by equilibrium studies, is consistent with the biexponential dissociation rate constants (at 20 degrees C K1 = 1.67 x 10(-3) M-1 sec-1 and K2 = ...
Findings from this study using a transplantable C3H mammary tumor failed to indicate interaction relative to growth parameters between two foci present in the same host. Whether they were growing alone or in the presence of a second focus, tumor growth rates were similar until the combined mass of multiple tumors approached that which was incompatible with survival. Only then was a difference in growth observed. Cytokinetic parameters, i.e., labeling index, primer-dependent DNA polymerase index or growth fraction, DNA synthesis time, tumor doubling time, and cell cycle time, were also similar whether tumors grew alone or in the presence of a second focus. Following removal of a tumor, changes were observed within 24 hr in the kinetics of the residual focus. There was an increase in labeling index (duration ⋍ 10 days) and primer-dependent DNA polymerase index with a decrease in the tumor doubling time. Minimal change was noted in DNA synthesis time and cell cycle time. The kinetic changes ...
Tuesday is Egg Sandwich day as Huffle always puts a couple of eggs in to boil while I am working. We ate our sandwiches watching a bit of Gotham and then I made the journey to fetch our new bath. It was about 30 minutes away and the traffic was awful. I saw about four accidents and six breakdowns, plus a couple of police pullovers. Something was in the air today. I had to lean heavily on my horn when someone tried to fit in the space between me and the car in front and there was clearly not enough room. I ended up getting off the highway because it was so snarled up. I picked up the bath and the shower screen (the nice man did all the lifting for me). On the way home I popped to a neighbour and picked up our ping pong balls for the Springfest game we are doing soon. *who knew my car could fit so much in it! Back home Huffle helped me to get everything out and then quickly went back to work. I was so tired I had to eat a bit of Lindt bunny, a cup of tea and sit on the porch and wait for the kids ...
Our initial hypothesis was that the different physiochemical properties of drugs affect their local concentration in the vicinity of receptors embedded in biologic membranes and therefore directly influence observed pharmacology. We have measured kinetic rate parameters for a series of β2-adrenoceptors ligands and compared them to the degree of interaction with phospholipids.. Direct kinetic binding studies with radiolabeled β2-adrenoceptor antagonists have been performed in the past but seldom in one study and often using a variety of different buffers and temperatures, making direct comparisons difficult. To our knowledge, our current study is the first time that kinetic rate constants have been derived for a large number of β2-adrenoceptor antagonists and agonists in a binding assay performed at physiologic temperature and sodium concentrations in the presence of guanine nucleotide. The fastest and the slowest dissociating ligands tested in this study differed in koff by up to three orders ...
1FKG: DESIGN, SYNTHESIS, AND KINETIC EVALUATION OF HIGH-AFFINITY FKBP LIGANDS AND THE X-RAY CRYSTAL-STRUCTURES OF THEIR COMPLEXES WITH FKBP12.
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BioAssay record AID 160811 submitted by ChEMBL: Pseudo first order rate constant to release model amine drug after esterase catalyzed hydrolysis at an enzyme concentration of 1 unit/mL.
Protein regulation systems with rapid kinetics. Regulation system works post-translationally resulting in rapid changes in protein level.
Protein regulation systems with rapid kinetics. Regulation system works post-translationally resulting in rapid changes in protein level.
This workshop will teach attendees how to answer important questions about enzyme mechanisms by designing the right experiments and interpreting them quantitatively. The workshop will be taught by Kenneth Johnson at The University of Texas and founder of KinTek Corporation, a leader in precision stepped-flow and quench-flow instruments for rapid transient reaction kinetics. It will present basic foundations and applications of kinetic analysis, then cover topics ranging from chemical kinetics and enzymology to pharmacokinetics and cell biology. It will demonstrate the use of KinTek computer simulation software to fit multiple data sets simultaneously, including kinetic and equilibrium measurements. Attendees will learn how to perform a wide range of experiments and interpret them rigorously, without simplifying approximations and errors inherent in fitting data using equations. ...
Published in J. Phys. Chem. B, 2010. Recommended citation: Jing Zhao, Chang Lu, Stefan Franzen*, J. Phys. Chem. B, 2015,119 (40), pp 12828-12837. http://pubs.acs.org/doi/abs/10.1021/acs.jpcb.5b07126 ...
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Time kinetics of virus titers in the BM after infection with LCMV. Mice were infected intravenously with LCMV-WE (2 × 106 PFU) and virus titers were determin
The global fitting of the aggregation curves above provides an explanation of the observed changes in half times and scaling exponents: the differential effect of a change in ionic strength on the rates of the individual processes in the aggregation reaction leads to shifts in the dominant mechanism of aggregate multiplication. In order to rationalize this difference in susceptibility to electrostatic shielding we consider the variation of each rate constant with ionic strength. In the plots in Fig. 6a and b we show the logarithm of the various rate constant versus the square root of ionic strength (this latter value includes the contribution from the added salt as well as the buffer; in the absence of added salt the buffer alone (4 mM sodium phosphate, 40 uM EDTA, pH 8.0) results in an ionic strength of approximately 12 mM). In a simple Debye-Hückel (DH)16,32-34 model of the effect of ionic strength, these points would be expected to lie on a straight line. However, DH is accurate only at low ...
Fluorescent molecules commonly shift to transient dark states, induced bylight or triggered by chemical reactions. The transient dark states can beused as probes of the local environment surrounding the fluorescent molecules,and are therefore attractive for use in biomolecular applications. Thisthesis explores the use and development of novel fluorescence spectroscopictechniques for monitoring transient dark states.This work demonstrates that kinetic information regarding photoinduced transient dark states of fluorescent molecules can be obtained from the time-averaged fluorescence intensity of fluorescent molecules subject totemporally modulated illumination. Methods based on this approach havethe advantage that the light detectors can have a low time resolution, which allows for parallelization and screening of biomolecular interactions withhigh throughput. Transient state images are presented displaying local environmental differences such as those in oxygen concentration and quencher ...
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State-of-the-art techniques, including single-channel and whole-cell patch clamp, microfluorimetry, conventional and two-photon fluorescence imaging, and molecular biology are used in studies spanning from the structure and function of single proteins to the intact muscle. Experimental results are compared with simulations of computational models in order to understand the findings in the context of the system as a whole.. These models have continually broken new ground with respect to integrating mitochondrial energetics, Ca2+ dynamics and electrophysiology to provide tools for studying how defective function of one component of the cell can lead to catastrophic effects on whole cell and whole organ function.. Important applications of this powerful approach have led, for example, to new insights about the specific changes in Ca2+ handling, and action potential remodeling in animal models of heart failure. By dissecting out the individual rate constants for Ca2+ uptake by the sarcoplasmic ...
Researchers have published the first part of what they expect to be a database showing the kinetics involved in producing colloidal metal nanocrystals -- which are suitable for catalytic, biomedical, photonic and electronic applications -- through an autocatalytic mechanism ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
We studied the unzipping of single molecules of double-stranded DNA by pulling one of their two strands through a narrow protein pore. Polymerase chain reaction analysis yielded the first direct proof of DNA unzipping in such a system. The time to unzip each molecule was inferred from the ionic current signature of DNA traversal. The distribution of times to unzip under various experimental conditions fit a simple kinetic model. Using this model, we estimated the enthalpy barriers to unzipping and the effective charge of a nucleotide in the pore, which was considerably smaller than previously assumed ...
Review of Reaction Kinetics quiz that tests what you know. Perfect prep for Review of Reaction Kinetics quizzes and tests you might have in school.
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Synonyms for Complex exponential function in Free Thesaurus. Antonyms for Complex exponential function. 1 synonym for exponential function: exponential. What are synonyms for Complex exponential function?
Shirinzadeh, Bijian and Zhong, Yongmin and Tilakaratna, Prasan and Tian, Yanling and Dalvand, Mohsen. 2010. A Hybrid Contact State Analysis Methodology for Robotic-Based Adjustment of Cylindrical Pair. International Journal Of Advanced Manufacturing Technology. (In Press ...
Figure 4. CAF-1 binds (H3-H4)2 tetramers and H3-H4 dimers with similar affinities, yet 2-fold different stoichiometries. (A) An overlay of the binding curves for CAF-1 titrated into a H3(L126R, I130R)-H4 double mutant that effectively prevents tetramer formation (gray squares) and a cross-linked (H3-H4)2 tetramer (triangle) with the wild-type H3-H4 curve from Figure 1 (dashed line). The curves are very similar to wild-type and produce dissociation constants of 5.5 nM for the double mutant and 9.0 nM for the cross-linked complex (Table 1). (B) Determination of the stoichiometry of the CAF-1•WT H3-H4 complex by titration of CAF-1 into a constant concentration of labeled H3-H4. Fluorescence change occurs until wild-type H3-H4 is saturated with CAF-1 and the ratio at this inflection point is equal to the number of CAF-1 molecules bound to a single H3-H4 complex. (C) Determination of the stoichiometry of CAF-1/H3(L126R, I130R)-H4 complex. The fluorescence change plateaus similar to that of ...
DI-fusion, le Dépôt institutionnel numérique de lULB, est loutil de référencementde la production scientifique de lULB.Linterface de recherche DI-fusion permet de consulter les publications des chercheurs de lULB et les thèses qui y ont été défendues.
The first product images of the Sapphire Radeon HD 4870 X2 have been posted at Pro-Clockers. This card is based on the reference ATi design and features a...
Federal regulators have cleared RXi Pharmaceuticals Corp. to start human studies of its first product, a treatment to reduce surgical scarring.
Determine the reaction order of a chemical reaction of the form rate AoAaBbexpEaRTkinetic order determination by wide area search and modeldata error minimizationkinfit attempts to determine the optimal order of reaction a and
u_x\) and \(\Delta p_x\) are the \(x\) component of the molecular velocity and the momentum transfered to the wall, respectively. The wall is perpendicular to \(x\) axis. Since the collisions are elastic, the molecule bounces back with the same velocity in the opposite direction.. The momentum transfer to the wall perpendicular to \(x\) axis as a molecule with an initial velocity \(u_x\) in \(x\) direction hits is expressed as:. \[\Delta p_x=2mu_x \tag{10.7.1} \]. The collision frequency, a number of collisions of the molecules to the wall per unit area and per second, increases with the molecular speed and the number of molecules per unit volume. \[f\propto (u_x) \times \Big(\dfrac{N}{V}\Big) \tag{10.7.2}\]. The pressure the gas exerts on the wall is expressed as the product of impulse and the collision frequency. \[P\propto (2mu_x)\times(u_x)\times\Big(\dfrac{N}{V}\Big)\propto \Big(\dfrac{N}{V}\Big)mu_x^2 \tag{10.7.3}\]. At any instant, however, the molecules in a gas sample are traveling at ...
MATH 1251. Calculus and Differential Equations for Biology 1. 4 Hours.. Begins with the fundamentals of differential calculus and proceeds to the specific type of differential equation problems encountered in biological research. Presents methods for the solutions of these equations and how the exact solutions are obtained from actual laboratory data. Topics include differential calculus: basics, the derivative, the rules of differentiation, curve plotting, exponentials and logarithms, and trigonometric functions; using technology to understand derivatives; biological kinetics: zero- and first-order processes, processes tending toward equilibrium, bi- and tri-exponential processes, and biological half-life; differential equations: particular and general solutions to homogeneous and nonhomogeneous linear equations with constant coefficients, systems of two linear differential equations; compartmental problems: nonzero initial concentration, two-compartment series dilution, diffusion between ...
Hi, Someone did a kinetics analysis of antibody binding to immune cells after ip injection of monoclonal antibody? How long time would it take fter injection before the target cells are stained? With best regards Petter Höglund Department of Microbiology Tumor and Cell Biology (MTC), Karolinska Institute, Box 280, S-171 77, Stockholm, Sweden -------------- next part -------------- HTML attachment scrubbed and removed ...
To bridge the gap, electrophysiologists have developed a tool to relate single-channel currents to the discrete-state Markov model (DSMM) for permeation. Ion distributions are segregated into a few representative "states," and connecting these states create a discrete-state diagram (Fig. 1, A→B). A random walk on the diagram leads to the net flux of the reaction (or permeation; Fig. 1 B) (Andersen, 1989; Miller, 1999). Single-channel current recordings under various experimental conditions were collected, and the set of rate constants for the diagram was optimized for the experimental data. These values have been used to draw the free energy profile of ion permeation (Fig. 1, B→C). In this procedure, the ion trajectory in real space is converted to the free energy profile as a function of the electrical distance. Thus, in this line of thinking, the permeation is considered as a simplified motion on linear coordinates of either the real space (Fig. 1 A) or the electrical distance (Fig. 1 ...
Characterization of simple and complex kinetic systems; experimental techniques, methods of data analyses; kinetic theories; reactions in gas phase, in solution and chemical chain reactions; deduction of reaction mechanisms from experimental rate laws.
a) Derive rate expressions for Langmuir-Hinshelwood, Eley-Rideal, and two-site mechanisms of surface reactions; (b) fit rate data to a LH rate expression to determine values of the kinetic constants and specify acceptable statistical measures of the goodness of fit.(a) Principles and guidelines for experimental design and collecting rate data; (b) methods for fitting rate data to empirical and theoretically based rate models; (c) the microkinetics approach to modeling reaction kinetics ...
We can measure the rate of an associative reaction and make changes in the reaction conditions to see how the rate is affected. For example, we could easily change the concentrations of the two reactants. All we have to do is change the amount of reactant we dissolve in the solution.. If we did that, we would find a linear relationship between each concentration and rate. If we double the concentration of new ligand, the rate of reaction doubles. If we triple it, the rate triples. Also, if we double the amount of metal complex, the rate doubles and so on. We can write the following expression, called the rate law, to describe this relationship:. \[ \text {Rate Law: Rate} = {-d[MLn]\over dt } = k[MLn][L]\]. This type of reaction is sometimes called a second order reaction. That term just refers to the mathematical form of the rate law, which depends on concentration times concentration, or concentration squared. The order of the reaction is the number of concentrations multiplied together in ...
An apparatus includes a first substrate; and a second substrate coupled to the first substrate, characterized in that, to control formation of a segregated phase domain structure within a chemical reaction product by controlling an amount of a constituent of a precursor that is present per unit surface area, at least one member selected from the group consisting of the first substrate and the second substrate defines a substantially regularly periodically varying relief with respect to basal spatial location.
Boltzmanns equilibrium theory has not received by the scholars the attention it deserves. It was always interpreted as a mere generalization of Maxwells work or, in the most favorable case, a sketch of some ideas more consistently developed in the 1872 memoir. In this paper, I try to prove that this view is ungenerous. My claim is that in the theory developed during the period 1866-1871 the generalization of Maxwells distribution was mainly a mean to get a more general scope: a theory of the equilibrium of a system of mechanical points from a general point of view. To face this issue Boltzmann analyzed and discussed probabilistic assumptions so that his equilibrium theory cannot be considered a purely mechanical theory. I claim also that the special perspective adopted by Boltzmann and his view about probabilistic requirements played a role in the transition to the non equilibrium theory of 1872.. ...
A complete and balanced set of enzyme activities is required for maintaining homeostasis. Enzyme kinetics, the quantitative measurement of the rates of enzyme-catalyzed reactions and the systematic study of factors that affect these rates, constitutes a central tool for the analysis, diagnosis, and treatment of the enzymic imbalances that underlie numerous human diseases. For example, kinetic analysis can reveal the number and order of the individual steps by which enzymes transform substrates into products, and in conjunction with site-directed mutagenesis, kinetic analyses can reveal details of the catalytic mechanism of a given enzyme. In the blood, the appearance or a surge in the levels of particular enzymes serve as clinical indicators for pathologies such as myocardial infarctions, prostate cancer, and damage to the liver. The involvement of enzymes in virtually all physiologic processes makes them the targets of choice for drugs that cure or ameliorate human disease. Applied enzyme ...
Slowed amyloid-beta turnover may explain agings association with increased amyloidosis and Alzheimers disease, say researchers.. Originally posted here ...
These are for a study guide, I have the answers but cant figure out how to do them. 1. Calculate K for the following reaction if a container initially filled only with 0.351 M NOBr has a [NOBr] = 0.298 M at equilibrium. 2NOBr |---|2NO + Br2 Answer: 8.4 x 10^-4 2. If a container is filled with SO2CL2 to an initial pressure of 3.58 atm, what will the equilibrium pressure of SO2, Cl2, and SO2Cl2 be given the reaction SO2 + Cl2 |----| SO2Cl2. Answer: SO2 = 0.308 atm; Cl2 = 0.308 atm; SO2Cl2 = 3.27 atm For this one, I calculated Kc=1.06 x 10^3 given Kp = 34.5 3. Calculate K for the following reaction: HClO + F- |----| HF + ClO- Given: Ka of HClO = 3.0 x 10^-8; Ka of HF = 7.2 x 10^-4 Answer: K = 4.2 x 10^-5
Chemical kinetics software for simulation and data fitting with applications in enzyme kinetics and equilibrium, protein folding, and pharmacodynamics.
The reaction mechanism is the series of steps by which a chemical reaction occurs.. A chemical equation does not tell us how reactants become products; it is a summary of the overall process.. The  sign has represents the reaction mechanism, but gives no indication of the steps in the mechanism. Reactants  Products. Slide 9. ...
Sigma-Aldrich offers abstracts and full-text articles by [Stéphanie Claus, Nathalie Mayer, Elisabeth Aubert-Foucher, Hanane Chajra, Emeline Perrier-Groult, Jérôme Lafont, Muriel Piperno, Odile Damour, Frédéric Mallein-Gerin].
The aim of this study was to develop a kinetic and transport model for diesel oxidation catalysts (DOC) with a satisfactory compromise between accuracy and computational demands for robust simulation of transient full-scale operation. Specifically the model accounts for surface concentrations of key species needed to capture transient features for typical lean exhaust conditions. In addition, the model accounts for transport limitations and distinguish them from reaction kinetics as well as apparent NO oxidation inhibition effects due to reactions. To achieve this, lab scale experiments were performed with DOCs with different platinum loadings and three different washcoat configurations of which two had an inert top layer. Both kinetic parameters for a detailed kinetic model and effective diffusivities were optimized for the experimental data using a single channel catalyst model. The experiments showed a clear effect of increased transport resistance for propene and CO and also that NO2 plays an
Tonic and use-dependent effects of Gd3+ in different conditions, in which blocker potency is altered. Gray lines illustrate traces elicited in the presence of blocker scaled to the magnitude of control currents in the absence of blocker. (A) In 10 mM Ca2+, application of 0.2 μM Gd3+ reduced peak currents by about one half during the first pulse (I1, tonic block), but to a much greater extent at the second pulse (I2, use-dependent block). (B) With 10 mM Ba2+, both tonic and use-dependent block occurred at 25 nM Gd3+. (C) Although Ba2+ currents inactivated more rapidly in channels with the β3 subunit rather than with the β2a subunit (compare with B), tonic and use-dependent effects of Gd3+ were similar for both β subunits. (D) Exemplar Ca2+ currents through the EEQE mutant of the selectivity locus recorded with and without 2 μM Gd3+. (E) Dose-response curves for tonic effect of Gd3+ determined for different experimental conditions (indicated). Tonic block is described by relative magnitude of ...
Chemical Reaction Kinetics: Concepts, Methods and Case Studies Author(s): Jorge Ancheyta Date: 2017-08-21 http://longfiles.com/qpaxgs10xpju/.html
Yorikawa C, Takaya E, Osako Y, Tanaka R, Terasawa Y, Hamakubo T, Mochizuki Y, Iwanari H, Kodama T, Maeda T et al. (2008) Human calpain 7/PalBH associates with a subset of ESCRT-III-related proteins in its N-terminal region and partly localizes to endocytic membrane compartments. J Biochem 143, 731-745 ...
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A bar chart is often a persons first choice of plot type when they want to compare values. This is appropriate when the values arise from counting. But when the value is a mean or median of data points taken from a sample, a bar chart is usually inappropriate. As discussed in our March Editorial and the accompanying Points of View and Points of Significance columns, a "mean-and-error" scatter-type plot or a box plot are more appropriate for sampled data. In summary, we strongly recommend that box plots be used when you have at least five data points, but for samples with 3-5 data points mean-and-error plots are more appropriate.. Box plots are heavily used in biomedical research in which statisticians have historically had considerable input into study design and analysis. But although similar types and quantities of sample data also appear in basic research (such as that published in Nature journals) box plots are much less common than bar charts in these manuscripts. Last year in Nature ...