What exactly is an enzyme?



Yes, I did google it but my pea sized brain can’t seem to understand it

In: Biology

Enzymes are proteins that make chemical reactions happen.

Most chemical reactions would happen so slowly as to be useless to life, so enzymes grab the various chemicals and create a little factory to do the job.

an enzyme is a protein with a catalitic effect. A catalitic is a molecule that is implied in a chemical reaction but that will not be consumed. It is used to either allow a certain reaction to happen or to make a reaction faster.

An enzyme is form of protein that triggers chemical reactions and scientists typically name enzymes with the -ase suffix.

For example, the human body likes the sugar glucose but milk doesn’t contain glucose, it contains a different sugar called Lactose. (-ose is the suffix for sugars) So the small intestine produces an enzyme named Lact*ase* which chops Lact*ose* into two smaller sugars, glucose and galactose, which the body can use.

Like all proteins, enzymes are very sensitive to temperature and will be destroyed if heated up.

Enzymes are like molecular tools – they make a job easier and are then available to be used again. As an analogy, think about how much easier it is to do something like opening a can with a can opener (the enzyme in this scenario) vs. just bashing the can on a table.

The sort of jobs enzymes are doing are usually sticking two molecules together (e.g. to build something) or breaking a larger molecule into two smaller pieces (e.g. digesting food molecules). The enzyme makes these processes faster or possible when they’d be slow / impossible otherwise. Unlike the molecules the enzyme is acting on, the enzyme isn’t permanently changed by the process (so it’s ready to be used again and again).

Going for an ELI5 style answer. Think about making bread. There’s the flour, egg, water, etc. but if you mix all those you don’t just get bread. You need the yeast to help it rise, and the oven to cook it. Without the yeast you’d get a very dense lump of ‘bread’, and without the oven you’d just have a sloppy mess.

Using the stomach and digestion as our example. The stomach is like the oven, but instead of heat it has stomach acid. Your teeth macerate the food and your stomach acid helps it break down, but it isn’t in the tiniest form yet your body needs to be able to absorb it. That’s where enzymes come in. For the bread, the yeast is that little extra that is needed to make it rise and be what we think of as bread. For the body, the enzymes are little protein strands that break down the more complex elements into the size our body can use.

On their own, enzymes aren’t really much as they are designed to break down a limited range of complex molecules, however, they are vital to our body doing its job properly.

(Really hope I didn’t over simplify and use a bad metaphor.)

It’s a protein catalyst.

In other words, it’s a molecule your body makes, for the specific purpose of making certain chemical reactions happen faster.

Your body makes enzymes (and other proteins) by stringing amino acids (a type of small molecule) together in a very careful sequence, coded for in your DNA. (That’s what genes are – each gene tells your body how to make one type of protein.) And this sequence of amino acids is chosen, so that it will naturally fold into a carefully designed shape, which performs a specific mechanical function at the molecular scale.

And, in the case of enzymes, that shape is designed to grab onto molecules, and either force them together or tear them apart.

For instance, take the ATP synthase in your mitochondria. These enzymes are along the interior membrane of the mitochondria, and there are more protons inside than outside (due to the action of other proteins).

So, the ATP synthase grabs onto ADP (a partially used-up energy carrier) and free phosphate. And its function, is to slam the ADP and phosphate together, to form ATP – a fully charged energy carrier. Then, it allows protons to flow through a built-in channel through the mitochondrial membrane, and uses the proton’s energy to push the free phosphate into an ADP – making ATP, a fully charged cellular energy carrier free for use elsewhere in the cell.

Or, take lactase. Lactase works by binding to a lactose, and pulling it apart, to produce glucose and galactose. Lactase has an entirely unrelated shape to ATP synthase, because it does an entirely different job.

Or, take DNA replicase. DNA replicase binds to DNA, grabs a DNA letter that matches its position on the existing strand, shoves it onto the free end of the new strand it’s building, and slides one position down the free strand. This requires its own specific shape.

If you think of trying to open nuts with your fists, compared to with a nutcracker. The Enzyme is the nutcracker, it’s something that doesn’t itself spend any energy, but it helps with the transformation.

For a technical definition, they are proteins which help lower the transition state of a reaction. Chemical reactions normally go between two stable states, and require a certain amount of energy to get over the barrier between them. Sugar doesn’t catch fire at room temperature, but if you heat it up, it can burn. An enzyme will let sugar burn at room temperature, by lowering the activation energy. They do this by weakly binding to the right parts of the sugar molecule, so it can fall apart more easily.

Enzymes are one type of protein. All enzymes are proteins*, but not all proteins are enzymes.

*Note that RNA molecules with a catalytic effect are termed “ribozymes”; these are the RNA equivalent of protein enzymes. Catalytic DNA molecules are termed DNAzymes or deoxyribozymes. The term enzyme implies a protein, not an RNA or DNA molecule.

An enzyme is something that consumes proteins (fish is high in protein, its a required molecule for your body to function). Enzymes themselves are also made out of proteins (and different enzymes will consume different proteins)