Can enzymes have moe than one active site?
340411
Yes.  There is no rule that says an enzyme can only have one active site.  Usually when there is more than one active site, they alternate in some fashion (try doing a web search on "alternating sites mechanism"--you will find plenty of examples).\n\nIn theory, the enzyme could also serve to couple two different reactions occurring at separate active sites.  I can't think of any examples off the top of my head right now.
954479
The optimal pH for enzymes is 7 while the temperature is 37 degrees Celsius. When the pH & temperature deviate from this set point, the enzymes (tertiary proteins) will denature (unravel) and lose their active sites and can no longer carry out catalytic processes.\n\nEnzymes are often held in the body in inactive forms so that lower pH of the stomach (HCL) will not destroy its structure. A high pH will slow raise the level of activation energy, thus slowing down the catalytic process.
40328
Proteins, including enzymes.
102190
Some enzymes will be destroyed. But most will still work. Remember every enzyme has has an optimum envornment that it works at i.e. temperature and pH. So when it gets to 112 a lot of enzymes are not working at their best to sustain life.
902443
You know that an enzyme in the liver, called catalase, breaks down H2O2 into H2O and O2? :) \n\nAll enzymes work at an optimal temperature and pH, and if the pH is too high or low, the enzyme is denatured (i.e. the shape is changed so that it cannot work on the substrate anymore). Thus, for very high and low pH, enzymes (acting as biological catalysts) denature and the reaction rate goes down.\n\n(There are exceptions to this, such as pepsin which works at an optimal pH of 1.)\n\nBut anyway, since catalase is not really one of the exceptions, the optimal pH for it is about pH7-pH8. Thus, the highest rate of reation would be the one in water. The other 2 would be kind of low.
723534
http://en.wikipedia.org/wiki/Enzyme\n\nyour answer is in industrial applications
282222
Well, enzymes ARE catalysts, at least to my knowledge.\n\nThere isn't sufficient information to describe the collision rate. In Kinetics, we determine the collision rate using the rate equation, and that is determined using the R.D.S. (rate determining step) or slow step of the mechanism of the reaction... and since you have none of these in your question, it's really quite impossible to answer!
1102769
Active and passive. Effectors change the function of the allosteric enzymes, and can make enzymes either active (allosteric activation) or passive (allosteric inhibition).
279154
The second one works really well, but not with all proteins.  I think the second one can look at several proteins at once too.  It's better suited for complex mixtures.
715813
The factors that affect enzyme activity are:pH, temperature, substrate concentration and even enzyme concentration, and inhibitors.\nThere a particular pH at the which the enzyme activity is maximum. This is called the pH optimum of the enzyme.A graph of pH versus enzyme activity shows a bell shape curve.\nThere is a temperature at which the enzyme activity is 100%. If the temperature is increased by 10 degrees Celsius then the enzyme activity becomes doubled. This is called Q10 of the enzyme. Further increase in the temperature lowers enzyme acivity and at higher temperature the activity is lowered further to become nil.\nSubstrate concentration is also important. At lower substrate concentration the enzyme activity is dependent on the substrate but at higher substrate concentration it becomes independent of substrate concentration.\nAt a very low enzyme concentration the enzymes suffer a kind of dilution and become inactivated.\nThere are substances that are called inhibitors.They impede enzyme or block enzyme activity.A competitive inhibitor binds the active site to block enzyme activity. A non-competitive inhibitor binds to enzyme at some other place to cause change in the three-dimensional structure of the enzyme in such a way that the configuration of the active site is changed and in this case the substrate won't fit in nicely to ensure catalysis.
747802
It is a type of inhibition that occurs when a molecule, of roughly the same shape of the substrate, enters the active site of an enzyme.  It blocks the active sight and hence prevents the substrate molecule to enter active site.\n\nThe reaction's rate is decreased as not all enzymes can metabolise the substrates, some of them being blocked by the inhibitor.
640976
Enzymes have an optimal pH and temperature for their function.  I cannot draw a graph here, so I'll just explain it.  If you graphed enzyme function on the y axis (left side) and temperature or pH on the x asix (bottom) you would see that the enzyme has very little function at the lowest temperature (or pH).  As you increase temp. or pH, the enzyme function will also begin to increase.  Eventually you reach the enzyme's optimal temp. or pH, and at that point, the enzyme funtion cannot increase any more.  If you continue to increase temp. or pH, you will see the enzyme function start to decrease.\n\nThis occurs because enzymes require a certain conformation to function correctly.  If the temp. or pH is not optimal, then the enzyme's shape will be slightly altered from it's optimal conformation.  The altered enzyme may still function, but not as well as the optimal conformation does.\n\nTry Googling "enzyme temperature graph" and then look for images.  You should find a graph similar to what I've described.
365934
an enzyme is a protein which lowers the free energy needed for it's target molecule or molecules to change their structure. for example - adding a phosphate group to another molecule. there are many ways in which the body regulates the enzymes capacity - some ways are by altering the substrate level - usually more substrate results in higher capacity - note that the change is NOT linear.\nanother way is by regulating the genes coding for these enzymes - inhibiting such a gene will result in lower enzyme levels and thus the overall capacity will be lower. note that in this case, each enzyme will work at it's usual capacity.\nwhat you are asking about is another way of controlling the enzymatic capacity. there are two general ways in which other molecules change the enzymes capacity - it can be competitive inhibition - a molecule which binds to the target site on the enzyme and lowers it's chance of binding to its' target molecule. the other method of inhibition is non-competitive inhibition - in this way a molecule binds to a site other that the target site, causing a conformational change in the enzyme and thus changes the affinity of the enzyme to it's target molecule.\na slightly different mechanism is used only in enzymes which have several sub-units (separate proteins that bind to each other to make one active enzyme). these make up many of the enzymes in our body. the mechanism used here is called allosteric change (note that all other regulation mechanisms are at work in these enzymes as well). allosteric change involves a binding of a molecule to the allosteric site which changes the conformation of the enzyme. this change can activate the enzyme and make it work more effectively, or it can inhibit the enzyme.\nso... an enzyme can be active, and by various mechanisms (involving not only other molecules but also "breaking" of the enzyme into active parts, changes in pH, temperature and more) it can change it's capacity - it can be lowered, inhibited almost completely or increased.
226403
well... sorry I can't help more specifically with your compounds...\n\n\na co-factor would be something that aids in the enzymatic process\n\na co-subtrate would be something that is required in addition to another subtrate which is ALSO altered by the enzymatic process\n\nThats my understanding of the matter... a substrate is acted upon by the process, whereas a factor is an additional required component but isn't acted on.
209054
Effect of enzyme on reaction
764697
active site interactions and the microenviroment surrounding it are more favorable to that substrate....it has a higher affinity for it.
755733
Peroxidase is a catalyst...catalysts speed up a reaction.\n\nIncreasing surface area of a substrate increases the rate of a reaction. The enzyme can bind on more places of the substrate to catalyze the reaction. The only limiting factor is the amount of enzyme versus the amount of substrate.