Enzymes- Chapter 5 Flashcards
What are catalysts and enzymes?
A catalyst is a substance that speeds up the rate of the reaction, without being used up. Enzymes are proteins used in metabolic reactions, as biological catalysts.
What is catalase and why must hydrogen peroxide be broken down?
An enzyme that catalyzes hydrogen peroxide to oxygen and hydrogen. This is essential as almost all reactions in a cells produce hydrogen peroxide, and this is a very dangerous substance.
How do we name enzymes, and what is a substrate.
Enzymes always usually end with -ase. Enzymes that break down carbohydrates are known as carbohydrases, enzymes that breaks down proteins are called protease, enzymes that break down lipids are known as lipases. The substance that causes an enzyme to react is known as a substrate. A substrate of amylase is starch.
How do enzymes work and what is an active site and the enzyme- substrate complex.
The enzyme has molecules with a very specific, shape they have dent that is known as the active site. The substrate molecule has a shape that is complementary to the active site. The substrate must be a perfect fit for an enzyme to fit. The enzyme changes the substrate molecule into new molecules known as products.
Active site: The part of the enzyme molecule to which the substrate temporarily binds too.
Enzmye-substrate complex : The short lived structure in which the substrate temporarily forms with the active site is known as the enzyme- substrate complex.
What are the factors that affect the efficiency of the enzyme?
The enzyme’s work best at their optimum temperature and pH, each enzyme has a different temp and pH, where they work best at.
When does denarturation occur?
When the enzyme is placed in temperatures, that are above 60 celcius, that is way higher than body temperature., they stop working. This temperature completely damages the enzyme, enzyme is said to be denatures, stops working completely
What the enzyme is places in pH’s that aren’t its optimum pH, they are damaged. Once again denatured and cannot catalyze the reaction.
How does the kinetic energy of molecules lead to more products being formed.
At 0 celcius, moleucules have very little kinetic energy- holds true for all low temperatures, so they move very slowly. When they move very slowly, less chances for substrate to collide wtth enzyme, so rarely enetering active site. And very few susbtrate moleucels are converted to products. But at high temperatures, the kinetic energy of molecules increase. They move faster and collide more frequently with more energy. The effective collision are more frequent, so the subtrate moles collide with the acitve site more frequently leaving to more of them converting to a product. This is why enzmye acctivity icnrease s with high tmperatures.
What happens to active site in denaturation?
HOwever when the kinetic energy increases, with a temperature above optimum, the enzyme moleucle begins to shake and lose thier molecules, so the active site, is no longer a complementary shape. to the susbstrate. When a susbtrate molecules collide with the active site it won’t fit. It cannot form an enzmy - substrate complex and is not converted to product. The activity of the enzmy therfore decreases.
And if the enzyme isn’t in its optimum pH then the enzmy molecule will lose its shape, causing it unable to bind with the substrate.
