# How do you find turnover number?

## How do you find turnover number?

The units of Turn over number (kcat) are kcat = (moles of product/sec)/ (moles of enzyme) or sec-1….Turnover Number

1. kcat = Turnover number,
2. Vmax = Maximum rate of reaction when all the enzyme catalytic sites are saturated with substrate and.
3. Et =Total enzyme concentration or concentration of total enzyme catalytic sites.

## What is the turnover rate of an enzyme?

Turnover number is defined as the number of substrate molecules transformed per minute by a single enzyme molecule when the enzyme is the rate-limiting factor.

What is the relationship between turnover number and k2?

At this point we define the turnover number: the number of substrate molecules catalyzed per second per enzyme molecule when the enzyme is saturated with substrate (Nelson and Cox, 2005; Becker et al., 2006). Hence, when the enzyme is saturated with substrate the turnover number (k2) becomes rate limiting.

### What is the turnover number for this enzyme and substrate?

The turnover number of an enzyme, is the number of substrate molecules converted into product by an enzyme molecule in a unit time when the enzyme is fully saturated with substrate. The turnover numbers of most enzymes with their physiological substrates fall in the range from 1 to 10^4 per second (Table link).

### Which enzyme has maximum turnover number?

Catalase
Catalase has the highest turnover numbers of all enzymes. One molecule of catalase can convert over 2.8 million molecules of hydrogen peroxide to water and oxygen per second.

How do you calculate a catalyst turnover number?

Turnover number (TON) = number of moles of reactant consumed/(mole of catalyst). Turnover frequency (TOF) = TON/time of reaction.

#### What is the fastest enzyme?

carbonic anhydrase
In fact, carbonic anhydrase is one of the fastest enzymes known. Each enzyme molecule can hydrate 106 molecules of CO2 per second. This catalyzed reaction is 107 times as fast as the uncatalyzed one.

What is the turnover number in Michaelis Menten equation?

The turnover number represents the number of substrate molecules that can be converted into product per unit time by a single enzyme.

## How is catalase used to study H 2 O 2?

Decomposition of hydrogen peroxide (H 2 O 2 ) at physiological levels was studied in human erythrocytes by means of a recently developed sensitive H 2 O 2 assay. The exponential decay of H 2 O 2 in the presence of purified erythrocyte catalase was followed down to 10 −9 mol/L H 2 O 2 at pH 7.4.

## What is the V max value of catalase?

Kinetic studies on the activity of catalase conducted using a pressure gauge indicates that the enzyme has a V max value of 0.0144, and K mvalue of 0.00275. The catalase appears to be affected by fluctuating pH values, and operates most ideally at pH 9.

How many molecules of hydrogen peroxide can catalase break down?

Catalase is remarkably efficient, and one catalase enzyme can convert 40 million molecules of hydrogen peroxide to oxygen and water per second. This enzyme is necessary as a condition for survival, as the catalase breaks down hydrogen peroxide from accumulating to dangerous levels.

### Are there reagents that show prevalence of catalase?

These direct measurements showed a clear prevalence of catalase even at very low H 2 O 2 concentrations. Reagents. Luminol, catalase, GPO, glutathione reductase, reduced glutathione (GSH), hydrogen peroxide, aminotriazole, NADPH, sodium hypochlorite, and sodium azide were from Sigma (Deisenhofen, Germany).