Search results
Results From The WOW.Com Content Network
Run-and-tumble motion is a movement pattern exhibited by certain bacteria and other microscopic agents. It consists of an alternating sequence of "runs" and "tumbles": during a run, the agent propels itself in a fixed (or slowly varying) direction, and during a tumble, it remains stationary while it reorients itself in preparation for the next run.
A single-displacement reaction, also known as single replacement reaction or exchange reaction, is an archaic concept in chemistry. It describes the stoichiometry of some chemical reactions in which one element or ligand is replaced by atom or group. [1] [2] [3] It can be represented generically as:
Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is different from chemical thermodynamics, which deals with the direction in which a reaction occurs but in itself tells nothing about its rate.
A good example of a substitution reaction is halogenation. When chlorine gas (Cl 2) is irradiated, some of the molecules are split into two chlorine radicals (Cl•), whose free electrons are strongly nucleophilic. One of them breaks a C–H covalent bond in CH 4 and grabs the hydrogen atom to form the electrically neutral HCl.
Determining the parameters of the Michaelis–Menten equation typically involves running a series of enzyme assays at varying substrate concentrations , and measuring the initial reaction rates , i.e. the reaction rates are measured after a time period short enough for it to be assumed that the enzyme-substrate complex has formed, but that the ...
Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents.
In most cases of interest in chemical thermodynamics there are internal degrees of freedom and processes, such as chemical reactions and phase transitions, which create entropy in the universe unless they are at equilibrium or are maintained at a "running equilibrium" through "quasi-static" changes by being coupled to constraining devices, such ...
No reaction takes place when these bulky groups are replaced by smaller methyl groups. Another example is a photochemical [2+2]cycloaddition with two alkene groups tethered through a silicon acetal group (racemic, the other enantiomer not depicted), which is subsequently cleaved by TBAF yielding the endo-diol. Without the tether, the exo isomer ...