1 / 3

The Enzymes

The Enzymes. Enzyme : is a protein that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions, into specific products.

gizela
Télécharger la présentation

The Enzymes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Enzymes Enzyme: is a protein that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions, into specific products. converting a specific ( AB). set of reactants (A,B) (called substrates) Almost all chemical reactions in a biological cell need enzymes in order to occur at rates sufficient for life. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. Enzymes are known to catalyze about 4000 biochemical reactions.

  2. Howdoes the changes of temperature affectEnzymesactivity? All enzymes have an optimum temperature at which it will work best. For example pepsin, an enzyme which works in the stomach has an optimum temperature of between 30-40 C, which is around the human body temperature. Although, beyond this optimum temperature, enzyme activity starts to decrease till when the reaction will be too slow and than it will “stop”. But in the same way as lower temperature will stop enzymes activity, when the temperature will be higher enzymes will have too much kinetic energy in themselves and they will “denature”. A denatured enzyme is considered useless because it cannot catalyze anymore. Lower temperature : Higher temperature: too slow reaction , till denatured enzyme It will stop

  3. Howdoes the changes of ph affectEnzymesactivity? In the same way as the enzymeshavean optimum temperature theyalsohaveanoptimum ph at whichitwillwork best. Forexamplepepsinhavean optimum ph of 2.0(very acid). As the changes of temperature also the changes of ph willaffect the activityEnzymes : if the ph of the enzymewillbenear the optimum level the reactionwillbefasterbutif the ph will far from the optimum ph the reactionwillbeslowertillitwill stop. Also the exceeding of ph would “denature“or “stop” the reaction, howevertheselimitswillbedifferentforeachEnzyme. Lower ph: too slow reactionHigher ph: denatured tillitwillstop enzyme

More Related