Enzymes are proteins that function as biological catalysts, which increase the rate of
reaction without being destroyed themselves by it (Campbell, et al., 2008).
Since not all
chemical reactions are fast acting, the slower reactions need a “boost” and that is where enzymes
A major process that occurs within our bodies is metabolic process, which tends to be a
If metabolic process were to occur at its normal slow rate than many cells
Thus, the vital role of enzymes is key for slow acting processes naturally occurring in
Enzymes are substrate-specific, meaning that only a particular substrate can react with
the enzyme to make a product.
The given substrate fits into a region of the enzyme called the
The active sites act like a “pocket” for the substrate.
In this particular lab the
enzyme being used was tyrosinase, which is found in many organisms including humans.
All enzymes have an active site, and an enzyme is “available” when the active site is
Then comes the substrate, which binds to the enzyme in the active site.
enzyme-substrates hydrolysis occurs, but it may not always be the case.
After, the substrate is
converted into products.
Then, the products are released.
There is a huge turnover count for
products because this cycle occurs in the thousands range per second.
The three main environmental factors that affect enzyme activity are temperature, pH,
and substrate concentration.
Temperature and pH are components of homeostasis, which help
keep our bodies’ cells in equilibrium.
As the bodies temperature increases so does the enzyme
Then at about 37° Celsius enzyme activity reaches its optimum, which also happens to
be the bodies average temperature.
After the optimum point, the enzyme activity begins to drastically decrease.
tend to be hypersensitive to high temperatures, because it is at this point that they tend to
denature, or “unwind.”
The two main things that cans cause the denaturing of enzymes are the
severity and duration of the heat.
Enzymes can be renatured if the temperature decreases back to
Tyrosinase is a naturally occurring enzyme in plant cells.
This particular enzyme causes
the brownish coloring from bruises in fruits and vegetables.
At the site of “injury” tyrosinase
reacts with pyrocatechol (a substrate) to then form hydroxyquinone.
In this particular lab, the
tyrosinase comes from potato cells (Couch and Beger, 2004).
The control experiment tested four different combinations of enzymes and substrates.
The first was the enzyme tyrosinase and the substrate pyrocatechol and the second was just the
The third test tube had just the enzyme tyrosinase, and the last test tube
had the enzyme tyrosinase and the substrate sucrose.
Temperature was the experiment being