What are the types of endonucleases?
Restriction endonucleases (restriction enzymes) are divided into three categories, Type I, Type II, and Type III, according to their mechanism of action. These enzymes are often used in genetic engineering to make recombinant DNA for introduction into bacterial, plant, or animal cells, as well as in synthetic biology.
Why should enzymes be kept on ice?
It is an article of faith among biochemists and molecular biologists that precious enzymes must be stored on ice. The usual reason given is that, at temperatures around freezing, enzyme activity is minimized and protein stability maximized.
What happens if an enzyme is too hot?
The shape of an enzyme also depends on its temperature. When enzymes get too warm, they get too loose. When the temperature is too hot, too cold, or unsteady, the enzymes will spend less time in their optimal shape which simply translates into having a less than optimal metabolism.
Does freezing kill enzymes?
Enzymes are proteins present in plants and animals. Freezing slows down, but does not destroy, enzymes in fruits and vegetables. That is why it is important to stop enzyme activity before freezing. The two methods you can use are blanching and adding chemical compounds such as ascorbic acid.
Why doesn’t it matter if enzymes keep getting added?
Why doesn’t it matter if enzymes keep getting added to a concentration graph? No, an enzyme can be used in a chemical reaction and then return to normal when the reaction is done.
What happens when enzymes are not in their optimal pH?
Describe: As the pH decreases below the optimum, enzyme activity also decreases. At extremely low pH values, this interference causes the protein to unfold, the shape of the active site is no longer complementary to the substrate molecule and the reaction can no longer be catalysed by the enzyme.
At what pH and temp The enzymes are highly efficient?
between 5-7
What would it take to increase the rate of enzyme activity?
As the enzyme molecules become saturated with substrate, this increase in reaction rate levels off. The rate of an enzyme-catalyzed reaction increases with an increase in the concentration of an enzyme. At low temperatures, an increase in temperature increases the rate of an enzyme-catalyzed reaction.
What are the 4 factors that affect enzyme activity?
Several factors affect the rate at which enzymatic reactions proceed – temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.
Does pH affect enzyme activity?
Enzymes are also sensitive to pH . Changing the pH of its surroundings will also change the shape of the active site of an enzyme. This contributes to the folding of the enzyme molecule, its shape, and the shape of the active site. Changing the pH will affect the charges on the amino acid molecules.
What is the effect when substrate is limited?
The catalytic site of the enzyme is empty, waiting for substrate to bind, for much of the time, and the rate at which product can be formed is limited by the concentration of substrate which is available. (B) As the concentration of substrate increases, the enzyme becomes saturated with substrate.
What do the activities of enzymes depend on?
Enzymes work by lowering the activation energy needed to start biochemical reactions. The activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings.
What is a high Km value?
We define Km as the substrate concentration that gives Vmax/2. The higher the Km of an enzyme, the LOWER its affinity for its substrate. This is because a high Km means that it takes a LOT of substrate before the enzyme gets to Vmax/2.
How do you calculate km?
From the graph find the maximum velocity and half it i.e. Vmax/2. Draw a horizontal line from this point till you find the point on the graph that corresponds to it and read off the substrate concentration at that point. This will give the value of Km.