Why does an enzyme no longer work when you raise the temperature too much?

Question

Huge biology midterm tomorrow and I'm not quite too sure about the answer.
Does anyone have somewhat of a thorough response?
Thanks =)

Answer 1

Remember these key points:
1. The functional structure of an enzyme is held together by hydrogen bonds.

2. These are very weak bonds.

3. When the temperature is increased the atoms of the enzyme vibrate more.

4. This vibration shakes apart the hydrogen bonds.

5. This breaks down the functional structure of the enzyme irreversibly.

Good luck and don't panic.

Answer 2

The temperture of a system is to some extent a measure of the kinetic energy of the molecules in the system. Thus the lower the kinetic energy, the lower the temperature of the system and , likewise, the higher the kinetic energy, the greater the temperature of the system.

Increases in the temperature of a system results from increases in the kinetic energy of the system. This has several effects on the rates of reactions.

1) More energetic collisions

When molecules collide, the kinetic energy of the molecules can be converted into chemical potential energy of the molecules. If the chemical potential energy of the molecules become great enough, the activation energy of a exergonic reaction can be achieved and a change in chemical state will result. Thus the greater the kinetic energy of the molecules in a system, the greater is the resulting chemical potential energy when two molecules collide. As the temperature of a system is increased it is possible that more molecules per unit time will reach the activation energy. Thus the rate of the reaction may increase.

2) The number of collisions per unit time will increase.

In order to convert substrate into product, enzymes must collide with and bind to the substrate at the active site. Increasing the temperature of a system will increase the number of collisions of enzyne and substrate per unit time. Thus, within limits, the rate of the reaction will increse.

3) The heat of the molecules in the system will increase.

As the temperatue of the system is increased, the internal energy of the molecules in the system will increase. The internal energy of the molecules may include the translational energy, vibrational energy and rotational energy of the molecules, the energy involved in chemical bonding of the molecules as well as the energy involved in nonbonding interactions. Some of this heat may be converted into chemical potential energy. If this chemical potential energy increase is great enough some of the weak bonds that determine the three dimensional shape of the active proteins many be broken. This could lead to a thermal denaturation of the protein and thus inactivate the protein. Thus too much heat can cause the rate of an enzyme catalyzed reaction to decrease because the enzyme or substrate becomes denatured and inactive.

Temperature optimum of an enzyme

Given the above considerations, each enzyme has a temperatuare range in which a maximal rate of reaction is achieved. This maximum is known as the temperature optimum of the enzyme.

check the site for more info

Answer 3

I've got two great words for you to used on your bio midterm to impress the hell out of them!

Denaturation and coagulation.

Heat, if only for a short period of time will cause the enzyme to denature. This is temporary, and means it changes it's shape. Once temp levels go down, the enzyme changes back.
When the heat is extended for a long enough period, coagulation can occur. This is when the bonds holding the enzyme are disrupted causing a perm. change in shape. This why high fevers can be dangerous is they stay for long periods of time.

Think about frying eggs, they're coagulated. You can't change fried eggs back into the liquid yokes right? No matter how much cooling, the egg will never take back it's original shape.

Hope that helped!

Answer 4

adding heat to matter is increasing the speed at which the outer shell electrons travel.

When the electrons on the outer parts of an enzyme move too fast, the ability of the molecules to latch on to a specific protein is decreased.

remember that the only thing that makes contact is the outer electrons. In an enzyme, the surfaces are complex, and must fit like a key in a lock. the heat (more energetic outer shell electrons) interferes with the accuracy of the surface.

This is why we get a fever when we have a virus. The increased temperatire lowers the efficiency of the cell's machinery, so less virus is manufactured.

Answer 5

did you recommend catalase??? theres no such component as catalayse. in any case, each and each enzyme has an optimal temperature and pH that choose the lively conformation of the of the protein molecule. So in actuality its lively internet site won't settle for any substrates because of the fact it has replaced shape by way of temperature or pH.

Answer 6

the receptors become denaturalized; that is, the molecules that make up the structure of the enzyme begin to break up and the enzyme becomes deformed.

it's like a melted styrofoam cup.

Answer 7

increased heat causes the enzyme, which is usually a protein, to denature by breaking the hydrogen bonds.

Answer 8

enzymes are made up of protein, heat causes the protein to denature

Answer 9

because heat causes it to break down