At some temperature, you'll start to denature (unfold) the protein and it will lose its catalytic function dramatically (and often irreversibly). Google "enzyme kinetics temperature dependence" for more info.Forensicsarefun said:Is there a reason why this happened??
Are you saying you heated the reaction from some low temperature up to 20°C? Did you cool the reaction first? The reason I ask is because 20°C is a little on the cool side of room temperature. I'd need more experimental details to understand what was going on.Forensicsarefun said:But would this happen at 20oC
This seems to imply that it was heated above room temperature, whereas before it was cooled below room temperature. In one instance, it sounds like the reaction slowed down as room temperature was approached from below, and in another instance it sped up as room temperature was approached from above. I would be curious to know if the rates at room temperature were the same for each experiment. To me, it sounds like some sort of reversible denaturation: essentially, as you heat a protein up, it can undergo conformational changes (changes in shape) that affect its catalytic activity. Usually these are irreversible (an example would be cooking an egg: once the proteins are denatured, there's no way to "uncook" the egg). However, it's not out of the realm of possibility that some mild temperature changes would result in reversible conformational changes, such that as the temperature was restored to its original value, the observed reaction rate would approach its original value as well. That's just my best guess, though. But keep in mind that since enzymes are so sensitive to lots of different experimental parameters, the experiments are particularly unforgiving in terms of sloppy lab technique. You have to be careful to make sure the variable you want to observe is actually isolated.Forensicsarefun said:yes it did - for another test, I cooled it down to room temp, and it sped back up
Heat slows down chemical reactions because it increases the energy required for molecules to collide and react with each other. This energy is known as activation energy.
An increase in temperature typically leads to an increase in the rate of a chemical reaction, as it provides more energy for molecules to react. However, at very high temperatures, the rate may actually decrease due to the breakdown of reactants or intermediates.
No, heat cannot completely stop a chemical reaction. Even at very low temperatures, there is always some amount of energy present that can cause molecules to react. However, lower temperatures will significantly slow down the reaction rate.
Increasing the temperature of a reaction can shift the equilibrium towards the products or reactants, depending on the specific reaction. This is because heat affects the Gibbs free energy, which determines the direction of the reaction.
No, different reactions may have different sensitivities to changes in temperature. Some reactions may be more affected by changes in temperature, while others may be less affected. Factors such as the reaction mechanism and the energy required for the reaction to occur also play a role.