mekanisme kerja enzim dan Regulasi enzim - materi biologi sma kelas bab

Hello Biota friends, welcome to the

school zone. The second material is the enzyme chapter. In

this material, we will study the

material about the mechanisms and regulation

of enzymes. In the previous material,

we have discussed a lot about enzymes

, starting from the definition, structure,

components, properties, and also the classification

of enzymes. Okay, let's just get straight to

learning. Okay, bro. In this material,

we will study the

working mechanism of enzymes, which has two

different theories, namely log and ke and

also indus fit. We will also

study the regulation of enzyme activity

which will involve activators

and inhibitors.

Well, we will discuss them one by one. Okay,

let's start with the working mechanism of enzymes.

So, friends,

there are two theories about the working mechanism of enzymes, namely the log and

K theory and also the indus fit theory. Let's discuss the

log ke theory first. Well, friends, do you still remember

the lesson in the previous material, namely

about how enzymes work, where

there is an enzyme substrate and its

active site. The substrate will then

attach to the active site of the enzyme

where it fits and form an enzyme-

substrate complex. Then a reaction occurs.

For example, a breakdown reaction

produces products.

So, the SOB mechanism of enzyme action like

this is a description of the

LCK and K theory where the substrate

can only attach or bind to

enzymes that have the appropriate active site

.

On the other hand, the enzyme will also accept a

substrate that fits the active site of the

enzyme.

So there must be a match between the active site of the enzyme and

its substrate,

friend. Well, friend, according to the log and K theory,

the shape of the active site of the enzyme is

not flexible or cannot change.

If we compare an enzyme to a lock

and the keyhole is the

active side of the enzyme. While the key

is the substrate. Well, the padlock hole

cannot be changed and can only be

entered with a specific key.

So, if the key doesn't fit, the

lock won't open. The

same thing applies to enzymes. So, in

this theory the active site of the enzyme

cannot adjust to the shape of

its substrate.

Well, whereas the indus fit theory is

the mechanism of enzyme action, that the

active site of the enzyme is more flexible or

can be influenced or induced by a

suitable substrate. Well, this means that the

active side of this enzyme can change

according to the shape of the substrate that will

bind to the enzyme. So, for example,

if there is a suitable substrate

but the shape of the active site of the enzyme

does not match the shape of the substrate,

then the active site of the enzyme will

adjust to the shape of the substrate.

Well, but remember, friend, even though in

this theory the active site of the enzyme can

adjust to the shape of its substrate, it

does not eliminate the specific properties of the enzyme

.

So, the enzyme side can only change

to adapt to the substrate that is

already compatible with the enzyme. For example,

if there is another substrate that wants to

bind to this enzyme but is not

compatible with the enzyme, then this enzyme

or that side of the enzyme will not

adjust to the shape of the enzyme.

So, the enzyme remains specific, right?

Well, okay. So that's how the

enzyme works, namely there are two

theories: log and indus fit.

We now move on to the material on

the regulation of sub-enzyme activity. Well, the regulation of

enzyme activity involves what are called

activators and inhibitors.

These two are compounds that

can regulate or control the work of

enzymes.

For activators, it will stimulate the

work of enzymes. Meanwhile,

inhibitors will inhibit the work of

enzymes. OK, so that we understand better, we

will discuss these regulations one by one

.

We start from the activator. Well, friend,

the activator can stimulate or

encourage the performance of the enzyme.

Well, my friend, this activator can only

attach to the allosteric side of the enzyme or to a

part other than the active site of the enzyme.

The function of this activator is to

stabilize the shape of the active site of the enzyme

so that the substrate that will bind

can bind more easily

to the enzyme. An example of an activator is the

Cl- ion

which regulates the amylase enzyme.

So, this activator will bind to the

allosteric side of the amylase enzyme and will

make the active side of the amylase enzyme

more stable and its shape

will be suitable for binding to

starch.

Well, okay, now you understand the function of the

activator.

Well, maybe some of us

think that the activator is the same as the

cofactor in the previous material. Then,

adding both of them has

an effect on the active side of the enzyme.

Well, it turns out that the two are

similar but not the same.

Although activators and cofactors are

of the same type, they

have different functions. If

the cofactor is attached to the active site of the

enzyme, its function is also to help

form the active site of the enzyme.

Meanwhile, the activator

attaches to the allosteric side of the enzyme or

to a side other than the active site of the enzyme. and

its function is only to

stimulate the active side of the enzyme so that it

can change and adapt to the

substrate. Well, okay, understand the difference

between the two, don't get them mixed up.

So it's an activator.

Now we come to inhibitors.

So, this inhibitor functions to

inhibit the performance of the enzyme. So, the

opposite of an activator, yeah. So, there are

two ways that inhibitors can inhibit enzymes. Well, the

first way is when the inhibitor attaches

to the allosteric side of the enzyme, it will

change the shape of the active side of the enzyme which

was previously compatible with the substrate, so

it will change to be incompatible with the

substrate so that the substrate

cannot attach to the active side of the enzyme

. Then, in the

second way, the inhibitor will

attach to the active site of the enzyme and will

create or block the path for the substrate

to attach to the active site of the enzyme.

Well, with these two methods, the enzyme

can no longer function because it is

inhibited by the inhibitor. Okay, bro.

Based on the binding, these inhibitors

can be divided into two types, namely

reversible inhibitors and

irreversible inhibitors. We will discuss them one

by one, but before that, Biologi TV

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Okay, buddy. Based on the binding,

inhibitors are divided into two. The

first is an irreversible inhibitor.

Well, as the name suggests, irreversible

means it cannot be reversed. Well,

for this type of irreversible inhibitor,

it will make or cause the enzyme

to be difficult to reactivate, as the

name suggests. The problem is that the inhibitor will

bind strongly to the enzyme. So

once it sticks, it will be very

difficult to remove and can even

damage the enzymes.

An example of an irreversible compound

is an organophosphate compound which is

found in the drug Muksob. So,

this organophosphate will attach

to the acetylcholine esterase in the

mosquito's nervous system. Then, once the

organophosphate has stuck, it

cannot be removed again and will cause

convulsions in the mosquito. Over

time, this will cause the mosquito to

die. So, this is how

mosquito repellent kills mosquitoes, friend. Okay,

now let's continue. The second is a

reversible inhibitor. So, this is the

opposite of irreversible, right?

Reversible means it can be

reversed.

So, this inhibitor bond is

not permanent, friend. or it can

come off again. That's why the enzyme can become

active again and even if the

inhibitor is removed, the enzyme

won't be damaged, friend. Because the

inhibitor is easily released from the

enzyme. Unlike

irreversible inhibitors, they are difficult to remove. If this is

easy to come off.

Well, for example, it's like

the antibiotic penicillin which inhibits the

active site of the enzyme that bacteria use

to make their cell walls, friend.

Well, but, my friend, these reversible inhibitors

can be divided into two, namely

based on where they attach. The

first is a competitive reversible inhibitor.

This means that this inhibitor will compete

directly with the substrate for the

active site of the enzyme. Plus,

this inhibitor also has

exactly the same shape as its substrate.

So they will compete to

attach to the active site of the enzyme. So,

if this inhibitor

attaches first, it will prevent the substrate from

attaching.

Then the second is a non-

competitive inhibitor. So this inhibitor does not

need to compete with the substrate because

this non-competitive inhibitor will

attach to the inactive side of the enzyme

and will stimulate the active side of the enzyme

to make or form an

active side that is not compatible with the

substrate.

Therefore, this will make the enzyme

unable to work by binding to the

sol substrate.

Well, but remember, these two inhibitors are

reversible or can

make the enzyme active again if the

inhibitor is removed from the enzyme

.

Okay, finally

our discussion in this material is finished. I hope what

I have conveyed can be useful,

digested and brought to life by all Biota friends

. Don't forget to watch and study the

next material and

other learning videos. So, see you next

video shop.

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