Introduction to Enzymes
Chemical reactions can be speeded up by substances called catalysts. In living organisms, metabolic reactions are controlled by catalysts called enzymes. Enzyme are made of chains of proteins. There are different types of enzymes, some speed up up metabolic reactions like respiration and fermentation, while the ones found in human body speed up the digestion process.
What is that?
Well, that bascially means catalysts can speed up chemical reactions - this is similar to using gemstones in farming games to speed up something.
In living organisms like us, metabolic reactions happen all the time - these are reactions that is essential to human life and there are lots of these.
Enzymes are the catalysts that speed these reactions up. They speed it up
Also...
Enzymes are catalysts, so they do not get used up.
Also, enzymes are not living things, so they cannot be killed. They can only be denatured (discussed later!).
Wait...so how are things sped up?
A thorough explanation is actually quite advanced, but a simplifid version is this:
Reactions only happen when different particles collide with each other, and very often when both particles are not compatible with each other reactions won't even happen. What an enzyme does is it adds or break up particle to increase the compatibility of a lot of particles, then releasing them so reactions can happen at a much quicking rate. (In reality it isn't that simple but it's rather complicated so we're trying to simplify it here.) For example, some help break down large molecues into smaller ones so the body can absorb the nutrients, which removes the necessity of another time consuming process that involes slowly waiting for those molecues (e.g. starch) to break down into smaller molecues (e.g. glucose).
In other words, it is like playing hide and seek, but enzymes forces those who are hiding to wear a big fat glowing balloon on their heads.
How does an enzyme work?
Enzymes do a lot of things, such as (but not limited to) building small molecues into large molecues, known as dehydration synthesis (making things by removing water), to breaking large molecues into small molecues, known as enzymatic hydrolysis (adding water to break things down). (Both of these are just examples and by no means are comprehensive!)
Here's how they work:
Every enzyme has an active site: a zone where only a particular kind of substrate can fit. Substrates can be anything that fits into the active site and gets changed into something else, known as the product.
Enzymes are very specific! Only a particular molecue can fit into the active site!
It's kind of like Lego - only the right shapes can fit into the right holes.
(This theory is called the "lock and key" theory for this is similar to locks and keys - only the right key can fit into the lock. However, there is another theory that is called the "induced fit", where enzymes changes its active site all the time because of its flexability. However, you do not need to know thses in great detail - just remember substrates can fit into enzymes to be broken down and built up!) Once it's there, enzymes can do whatever they want, from building things with it to breaking it down.
Here's a GIF showing how it works:
Well, that's a brief introduction to how they works! More details would be explored later!
Here's an example: When the salivary enzyme amylase binds to a starch, it catalyzes hydrolysis, which is the breakdown of a compound by water, resulting in maltose, a simpler form of starch.
If the shape of the enzyme changes, or its active sites changes shape, it will no longer work, and this is called denatured. Why does that happen? This will be discussed in a later article!
