Search results
Results from the WOW.Com Content Network
In chemistry, the term "turnover number" has two distinct meanings.. In enzymology, the turnover number (k cat) is defined as the limiting number of chemical conversions of substrate molecules per second that a single active site will execute for a given enzyme concentration [E T] for enzymes with two or more active sites. [1]
The katal (symbol: kat) is that catalytic activity that will raise the rate of conversion by one mole per second in a specified assay system. [1] It is a unit of the International System of Units (SI) [1] used for quantifying the catalytic activity of enzymes (that is, measuring the enzymatic activity level in enzyme catalysis) and other catalysts.
Most enzymes have a rate around 10 5 s −1 M −1. The fastest enzymes in the dark box on the right (>10 8 s −1 M −1) are constrained by the diffusion limit. (Data adapted from reference [1]) A diffusion-limited enzyme catalyses a reaction so efficiently that the rate limiting step is that of substrate diffusion into the active site, or ...
The enzyme unit, or international unit for enzyme (symbol U, sometimes also IU) is a unit of enzyme's catalytic activity. [1]1 U (μmol/min) is defined as the amount of the enzyme that catalyzes the conversion of one micro mole of substrate per minute under the specified conditions of the assay method.
See Weight for detail of mass/weight distinction and conversion. Avoirdupois is a system of mass based on a pound of 16 ounces, while Troy weight is the system of mass where 12 troy ounces equals one troy pound.
Conversion of units is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property.
In many occupational scenarios, the hourly dose rate might fluctuate to levels thousands of times higher for a brief period of time, without infringing on the annual limits. The conversion from hours to years varies because of leap years and exposure schedules, but approximate conversions are: 1 mSv/h = 8.766 Sv/a 114.1 μSv/h = 1 Sv/a
Some airspeed indicators in aircraft prior to the mid-1970s indicate in miles per hour plus knots (1 knot = 1.15 mph) or kilometers per hour (1 knot = 1.85 km/h). A primary flight display with the indicated airspeed (IAS) displayed in the form of a vertical "tape" on the left.