Catalyst substance that speeds up chemical
(metabolic) reaction. The catalyst itself
it is available as a result of their actions. That function as biological catalysts called enzymes
. They
consist of C, H, O and N. Sulfur (S) may also be present >> << As we have seen in the page >> << function of proteins is determined by their amino acid
staff as well as their shape. Enzymes
control of cellular responses. As you remember, the reactions that break down substances and
of energy called catabolic reactions. Examples
<< are >> breathing and digestion. Other types of reactions
called anabolic reactions. These reactions
consume (use) of energy. These reactions build larger and complex molecules from smaller ones. Photosynthesis and growth of muscle mass from amino acids are examples of anabolic reactions. The enzymes consist of ball >> FORM.
, Form of the enzyme allows it to receive only one type of molecule, that molecule to be
fit in its form. The place where the substance contained in an enzyme called AC
and substances which fits into the active center is called the substrate. Enzyme action occurs when
enzyme and substrate encounter. During the collision the substrate slots in
active center of enzyme. Collisions occur due to rapid random motion of molecules
. When lining
connects to the entire structure of an enzyme called enzyme-substrate complex. Substrate >> << is
change the action of the enzyme, and then releases the product. The enzyme then free to join another substrate. Enzymes can be
anabolic and catabolic. The same enzyme can be used to form smaller molecules
a large molecule, or do the opposite. Example catabolic enzyme amylase. Amylase converts starch
in maltose. Example anabolic enzyme DNA polymerase. This enzyme
DNA. As noted earlier,
substrate must fit into the enzyme active center. Some substrates are suitable
nice in the active center. This situation is called
lock and key model. The enzyme is a complex protein molecule
but there is a site where the reagent molecule until
in "random collisions. The enzyme is sometimes referred to as
"
castle and the original substrate molecule reagents as" key ", so it
called" lock "
mechanism. This also explains why enzymes
very specific (specificity buy lasix generic of enzymes). You need the right molecular key >> << for a particular molecular lock. Even when
different substrate molecules are present only those who have some form >> << addition to the active center can contact
AC enzyme. Sometimes the form
active site should be slightly modified. This situation is called >> << induced Fit model. The active enzyme center
takes the form of closely complementary bases Reason
fixed in the active center of enzyme. AC changes its form
conducting substrate more tightly and strained it. The enzyme-substrate complex is formed by
. Substrates undergo chemical changes and new >> << substances, the products formed. The product comes with the active center.
named their watermark letters
ase added to the title substrates Examples: ..
protease - breaks down proteins in meat,
nuts, eggs and cheese
lipase - breaks down fats contained in most dairy products
, nuts, butter and meat
Pulp - breaks down cellulose, plant fibers, not
found in the human enzyme
less activation energy. This energy input necessary to bring
on the reaction. Enzymes allow reactions occur with less >> << energy than would be necessary if the enzyme is not present. 2. Adjust >> << thousands of metabolic reactions in the cell in the body. cell activity determined by the fact that enzymes
active in the chamber at a time. activity of cells changed by removing specific enzymes and
/ or synthesis of new enzymes. Enzyme inhibitors
molecules that interact in some way with the enzyme to prevent it from working
in the usual manner. Poisons and drugs are examples of inhibitors of enzymes. inhibitors of the enzyme to change shape and make it nonuasable for backing >>. << inhibitors may also act as a substrate and binding to the enzyme.
This prevents the enzyme from binding to its intended substrate. When this happens << enzyme called >>
denaturated. At 0 ° C
action of the enzyme is low, as the movement of molecules is low. This leads to the
frequency of collisions between enzyme and substrate at a low level. Increase speed
temperature of the movement of molecules and, hence, the frequency of collisions
increases as increases the enzyme action. human enzymes, biologically work best at a temperature of 37 degrees Celsius
. in the temperature of the enzyme changes shape and
enzyme becomes denatured
. temperature above 50 degrees Celsius will denaturation of enzymes most people. Most enzymes work best at pH 6.8
. When the pH is outside this range the enzyme loses
its shape and is denatured. ideal (optimal) pH for most enzymes 7. (Click reset to see this animation again).
Some enzymes work best at other levels of pH
The following graphics show it. << How >> concentration of the enzyme increases the reaction rate increases,
, provided that the substrate in excess. At low concentrations of substrate concentration increase >> << will increase the reaction rate. However, after concentration
such that all active centers of enzymes are constantly in use
, the further increase of the substrate will have no effect on the rate
reaction. it from which can be
attached to each other insoluble materials, or enclosed in a membrane or gel
. This can provide increased resistance to changes in conditions, such as
either. It also allows enzymes to be held in place throughout the reaction, after
which are easily separated from products and can be used again. Immobilised enzymes
used in the bioreactor These procedures are used to produce many products
accustomed to use microorganisms See
to discuss bioreactors adsorption ...
In this method the enzyme attached to the support of support can be ceramic, glass or
plastic membrane Housing: .. In this method, enzyme
enclosed in a porous gel membrane capture. enzymes. held in sodium alginate gel is common to use the gel gel allows the substrate to enter and leave product
,
, chemically related or supporting each other ... See p 95 textbook This facilitates cleaning
product like separation of enzymes the products easily
done. It is easy to restore and re-enzymes. This leads to a more economical process. enzymes remain functional much longer
as this soft process obtained from glucose. Fructose is sweeter << >> than glucose, and is used in soft drinks and other sugary foods. enzymes used to modify penicillin in new, more extensive use of antibiotics << >>. << >> For bacterial enzymes can be used and immobilized << >>
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