Get to know the properties of enzymes: definition, components, and how they work

Properties of Enzymes – When digesting food, there are biomolecular substances in the form of proteins that
will help change the molecular shape of food substances into substances needed by the body.
For
example, sugar is converted into energy that is beneficial to the body.
These biomolecules are
called enzymes.
In this article, we will discuss the properties of enzymes and the various
things that are in them.

Enzymes themselves play a role to help metabolism. So it is very important for human body.
The way enzymes work is to react with substrate molecules to produce compounds through organic
chemical reactions that require lower activation energy.
So it will speed up the chemical
reaction, because a chemical reaction with a higher activity energy requires a longer time.

Definition of Enzyme

The word enzyme itself comes from the Greek “en” which means in and “zyme” which means yeast.
That way, we can conclude that enzymes can be interpreted as substances in yeast. In
other words, the meaning of enzymes here is a group of proteins that have a special function, namely as a
biocatalyst that is useful for helping the body’s metabolic processes such as the formation of cell building
compounds, protein breakdown, glucose burning, and polysaccharide breakdown.

Meanwhile, enzymes can also be interpreted as a protein that is useful as a catalyst in breaking reactions
and also the formation or metabolism of a substance that occurs in the cells of a tissue.
A
catalyst is a substance that affects the speed of a reaction without affecting the end result.
The substance will not participate in the reaction. So the shape will not
change.

Enzymes are protein compounds that have large molecules. There are several enzymes that
consist only of polypeptides and do not contain chemical groups other than amino acid residues.
However, there are other enzymes that require additional components for their activity.
This component is called the prosthetic group. Prosthetic groups are ions or molecules
needed by some enzymes to carry out catalytic processes.

Where this prosthetic group can be an inorganic molecule or a cofactor such as Fe2+, Mn2+, and Zn2+ ions;
or in the form of complex organic molecules (coenzymes). Such as vitamins B1, B2, B6,
niacin, and biotin.
Coenzyme will not be affected by heating or is thermostable.
Many enzymes consist of a protein part and a non-protein part. The protein portion of
the enzyme is called the apoenzyme, which is denatured by heating.
An enzyme whose structure is
perfect and active, together with its coenzyme or metal group, is called a holoenzyme.

How Enzymes Work

One characteristic of enzymes is how they work specifically. That means, enzymes can only work
on certain substrates.
Then, how does an enzyme work? There are two theories that
explain how enzymes work, including:

1. Lock and Key Theory

The lock and key theory was first put forward by Emil Fischer, in 1894. In this research theory, enzymes
will be linked to a substrate with a similar or specific form on the active site of the enzyme.
This theory is called the Lock and Key Theory. Where the enzyme is described as a key
that can open a substrate described as a lock.

Because there is a similar side between the lock and the lock, they can be opened and closed.
However, this theory has a drawback, which is that it cannot explain the stability of the enzyme
when it undergoes a transition from the point of the enzyme reaction.

2. Theory of Induction Accuracy

The active site of the enzyme itself is flexible, so it can change shape according to the shape of the
substrate.
It has been explained previously that the enzyme is a catalytic protein.
A catalyst is a chemical agent that changes the rate of a reaction without being changed by the
reaction.
Enzymes can do this based on their effect on the activation energy required by each
chemical reaction.
Activation energy is the energy required to break down the reactants.

While the role of enzymes is to lower the activation energy limit needed to start the reaction.
Lowering the energy limit allows the chemical reaction to occur at a lower temperature.
This is important because the majority of molecules associated with life processes are very
sensitive to high temperatures.

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Enzyme Properties

Enzymes have an important role for the human body and for the ongoing life of an organism.
Therefore, we must understand the nature of enzymes. The following are some of the
properties of enzymes that we need to understand, including:

1. As a Catalyst

The first characteristic of an enzyme is to act as a catalyst. Enzymes are catalysts that can
change the rate of a reaction without participating in the reaction.
Without enzymes, a
reaction is very difficult to occur, whereas in the presence of enzymes, the reaction speed can increase up
to 107 to 1013 times.
For example, the catalase enzyme contains iron (Fe) ions which can
decompose 5,000,000 hydrogen peroxide (H2O2) molecules per minute at 00C.
The hydrogen peroxide
can only be broken down by iron atoms, but one iron atom will take 300 years to break down a number of H2O2
molecules which one catalase molecule containing one iron atom can break down in just one second.

2. Enzymes Work Selectively and Specifically

An enzyme will work specifically, that means certain enzymes can only make changes to certain substances as
well.
In other words, enzymes can only affect one reaction and cannot affect other reactions
that are not their field.
One enzyme will be specific for only one substrate. For
example, the catalase enzyme can only hydrolyze H2O2 to H2O and O2.

3. Enzymes Have Alternating Properties

The next characteristic of enzymes is that they can work back and forth because they can participate in the
reaction without affecting the final product and will be formed again as an enzyme as a result of the
reaction.
When participating to react, the chemical structure of the enzyme will also change.
But at the end of the reaction, the chemical structure of the enzyme will re-form as before.

For example, the lipase enzyme can convert fat into fatty acids and glycerol. Vice versa,
lipase can also unite glycerol and fatty acids into fat.
In addition, enzymes can not only
decompose complex molecules, but can also form complex molecules from simple molecules or reverse
reactions.

4. Like Protein

Enzymes have most of the properties of proteins that are affected by temperature and pH. At
low temperatures, the protein enzymes will experience coagulation and at high temperatures will experience
denaturation.
Because enzymes are composed of protein components, the properties of enzymes are
classified as colloids.
Enzymes themselves have very large inter-particle surfaces so that
their field of activity is also large.

5. Enzymes are thermolabile

Enzyme activity can be affected by temperature. If the temperature is low, the enzyme work
will slow down.
The higher the temperature of the chemical reaction affected by the enzyme, the
faster it will be.
However, if the temperature is too high, the enzyme will experience
denaturation.

6. Only Needed in Small Amounts

Because the enzyme acts as a catalyst, but does not participate in the reaction, the amount used as a
catalyst does not need to be large.
One enzyme molecule can work over and over again, as long
as the molecule is not damaged.

7. Is a colloid

As previously explained that enzymes are composed of protein components. Therefore, the nature
of the enzyme is classified as a colloid.
Enzymes themselves have a large surface area between
particles.
So that the field of activity also tends to be large.

8. Enzymes Can Lower Activation Energy

A chemical enzyme can occur when the molecules involved have enough internal energy to carry it up the
energy hill to a reactive state called a transition stage.
The activation energy of a reaction
is the amount of energy in calories needed to bring all the molecules in 1 mol of a compound at a given
temperature to a transition level at the top of the energy limit.
If a chemical reaction is
added with a catalyst in the form of an enzyme, the activation energy can be lowered and the reaction will
run more quickly.

9. Does not determine the direction of the reaction

Enzymes do not play a role in determining which direction the reaction is going. The compound
that is more necessary is the point of direction of a chemical reaction.
For example, a body
that lacks glucose will be able to break down reserve sugar or glycogen and vice versa.

Enzyme Components

Enzyme itself has three types of constituent components in it. Starting from Apoenzymes,
Cofactors, and Prosthetic Groups.
Here are some complete explanations of the three
types.

1. Apoenzymes

Apoenzyme is part of the active enzyme which is composed of proteins that are easily changed to environmental
factors that surround it.

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2. Cofactors

Cofactors are part of the non-protein components present in enzymes, namely in the form of inorganic ions or
activators, in the form of metals that have weak bonds with enzymes, Fe, Ca, Mn, Zn, K, Co, Chloride Ions, and
Calcium Ions.

3. Prosthetic Group

The prosthetic group is an organic compound that has a strong bond with the enzyme. Flavin
Adenine Dinucleotide (FAD), Heme, and Biotin are part of the Prosthetic Group which contain iron and play a
role in giving extra strength to enzymes, especially Catalase, Cytochrome Oxidase, and Peroxidase.

Factors Affecting Enzyme Activity

Below are several factors that can affect enzyme activity, including:

1. Temperature (Temperature)

The first factor that can affect enzyme activity is temperature or temperature. Enzyme
activity will increase with increasing temperature to the optimum limit.
This is because
enzymes are composed of protein.
Therefore, at high temperatures and exceeding the maximum
limit, it can cause denaturation of proteins or enzymes that are damaged.

At 0 degrees Celsius the enzymes are inactive, but not damaged. If the temperature is returned
to its normal position, the enzyme will be active again.
The maximum temperature for enzyme
activity in humans and warm-blooded animals is 37 degrees Celsius, while in cold-blooded animals it is 25
degrees Celsius.

Enzyme workability will decrease if it is above a certain temperature. This is because heat
will disrupt hydrogen bonds, ions, and various kinds of bonds that can stabilize the active form of the
enzyme.
That way, the enzyme which is a protein will undergo a denaturation process.

2. Degree of acidity or pH

It should be understood that enzymes have a unique optimum pH. The optimum pH for enzymes can
be alkaline or acidic.
Most of the enzymes in the human body have an optimum pH between 6 and
8. For example, the enzyme trypsin degrades protein.
However, there are some enzymes that are
active in acidic conditions, for example the enzyme pepsin.
Changes in pH can affect changes in
amino acids on the active site.
So that it can block the active side of the enzyme that
combines with the substrate.

3. Enzyme and Substrate Concentration

Usually, the concentrations of enzymes and substrates are directly proportional to the rate of reaction.
This means that if the enzyme concentration doubles, while other factors remain the same, the
reaction rate will double.
Constant conditions are achieved if the enzyme has bound all the
substrates to be catalyzed.
Although the enzyme levels are raised. When the enzyme
level remains the same, but the substrate level is increased, the reaction rate will increase until it
reaches a constant state, that is, when all the substrates are bound by the enzyme.

4. Activating Substances

There are certain chemicals that can increase enzyme activity. For example, salts and also
alkali metals in dilute concentrations, namely 2 percent to 5 percent, can stimulate the work of enzymes.
Likewise with metal ions Co, Mg, Ni, Mn, and Ci. This can support the theory of
Induced Accuracy.

5. Inhibiting Substances

Some chemicals can inhibit the performance of enzymes. For example, salt contains mercury and
cyanide.
There are three types of inhibitors or inhibitors that need to be understood.
Here is more information:

a. Competitive Inhibitors

In this inhibition, there is an inhibitor substance that has a structure similar to the structure of the
substrate.
That way, the inhibitor substance with this substrate will compete with each other
and be able to join the active site of the enzyme.
This inhibition process can be overcome by
increasing the concentration of the substrate.

b. Noncompetitive Inhibitors

Noncompetitive inhibitors may be associated with enzymes that are outside the active site. So
the enzyme will lose its activity.
Therefore, the surface of the active site cannot contact the
substrate.

c. Feedback Inhibitors

The end result of a reaction can inhibit the working process of the enzyme in the reaction itself.

Functions of Enzymes in the Human Body

One of the most important functions of enzymes is to aid in the digestive process. The way
enzymes work is by changing the form of food into energy.
For example, enzymes in the salivary
glands, intestines, pancreas, and stomach.
Enzymes will break down proteins, fats, and
carbohydrates.
Not only can produce energy and nutrients, enzymes also function to help the
growth and repair of cell tissue.
Besides having a function to help the digestive process,
enzymes can also help:

a. Breathing process
b. Build
muscle

c. Helps nerve function
d.
Cleansing the body of various poisons

Another function of enzymes is DNA replication. Each of these cells divides, then there needs
to be a process of copying DNA.
The role of the enzyme here is to help the replication process
by unwinding the DNA, then copying the information.

Those are some explanations about the nature of enzymes and the various things that are in them.
Hope it is useful.

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