Enzyme
In 1833 Anselme Payen
discovered enzymes which are
biological catalysts that increase
the rate of reaction without
being consumed during the
process. Because they are not
damaged during the reaction,
enzymes may be utilised again.
Substrates are the molecules
that enzymes may act on, and
they are transformed into a
variety of other compounds
which are referred to as
products. As a result, enzymes
are essential for several
processes, such as digestion and
liver function. This indicates that
having few or too many enzymes
can have a significant impact on
the body and lead to health
problems. This demonstrated
that while enzymes aid in
digestion and break down fats,
proteins, and carbohydrates,
their improper function might
result in health issues.
,There are two primary theories for how the shapes of the active site and its substrate interact.
Lock and key model → Enzymes are large molecules made of proteins. A substance known as a
catalyst, which increases the velocity of a chemical reaction by offering a different route with a lower
activation energy. The energy needed to initiate a chemical reaction is known as activation energy.
This implies that the chemical process would take longer to complete without enzymes.
The lock and key theory explains the
function and activity of enzymes. Every
enzyme has a unique shape and structure
known as a "activation site" that is joined to
a certain substrate. The substrate pairs well
with the enzyme's active site, in order to
create an enzyme-substrate complex, and
the substrate must fit into the active sites. A
product is created from the attached active
site in the substrate. When the reaction is
completed, the products are released, and
the active site then reacts with another substrate. The hypothesis describes how the enzyme
functions similarly to a key that is placed into a lock and only works because it has the right shape.
Because of this, the complementary structure and bonding group of enzyme active sites allow them
to fit together as a key fits a lock.
Induced fit model →The induced fit theory, which Koshland published in 1958, describes how the
process changes shape.
The model describes the formation of the enzyme-substrate complex by the attachment of active
sites to the substrate. The fact that the enzyme may alter its shape and structure to fit and collide
with the substrate suggests that it is flexible rather than rigid. As a result, the altered structure of the
enzyme helps it to catalyse reactions more effectively. Hence, the model is unable to describe how
the chemical changes take place during the process.
, Enzymes are globular proteins with a high level of specificity that are referred to as enzymes. Enzymes are big protein molecules that may aid in catabolic
reactions, which break down things, and anabolic reactions, which build things up. As a result, they can function either inside the cell (intracellular enzyme)
or outside the cell (extracellular enzyme). Furthermore, the collision hypothesis suggests that enzymes move randomly and collide with substrates with
sufficient energy to cause reactions to occur. This results in the formation of an enzyme-substrate complex that releases the product and the enzyme is then
free to collide with another enzyme.