hey everybody Doctorow here let's start about enzymes now first just you have to be in awe of these things you have to understand that life would absolutely not be possible without enzymes let's go ahead and take a look at why so first there's a couple of things most enzymes are made of proteins so there are there are ribozymes and there are enzymes that are made of other things but the huge majority of protein of enzymes are made of protein that's the first in the note secondly usually you can tell an enzyme by its name it will end in ace ASE so an ace ending it's just a couple of quick things here but then how do they work see maybe you've heard this but enzymes work by lowering activation energy as you can see here on the left and right hand sides both these images are showing different amounts of energy being needed to turn reactants into products so without an enzyme you would have a high activation energy and it would take too much energy in most situations with an enzyme you're going to see a lower activation energy so this I don't like these pictures though just because they make it look like okay an enzyme make something work a little bit better right but a real a real picture would be take the picture on the on the right hand side that's what an enzyme would look like or a reaction would look like with an enzyme with a low activation energy on the other side this should be to the roof at least as far the difference between having an enzyme and not is just unbelievable so let me give you a number here to keep in mind enzymes can speed up chemical reactions can make chemical reactions occur up to a billion times faster so we're not talking about a 25 or 50 percent improvement we're talking about with an enzyme we're alive and having metabolism without it we couldn't do that we don't have a century to wait for a reaction to occur it has to happen now so that's the first key number to remember that enzymes can speed up chemical reactions up to a billion times faster all right the other key thing to note about enzymes is they're called biological catalysts so a catalyst is something that can speed up a chemical reaction but the key here with the biological catalysts is not only does it speed up a chemical reaction we just said up to a billion times faster but it doesn't change the product and it's not used up in their reaction to think about that if we had an enzyme that turned this reactant into a product but broke it along the way that wouldn't do us any good imagine if we spent the energy to build an enzyme and that enzyme was broken as it as it produced this product would be a complete waste so the same enzyme can work over and over and over again the turnover rates of some enzymes are 20000 times a second so one enzyme can do can perform up to 20,000 reactions in a second and it can do that for days or weeks until it has to be replaced so that's why it's important that it's a catalyst that it speeds up the reaction but doesn't change the reaction or itself but the other important thing here is is that their biological catalyst and what I liked it when I say when I say that what I think of is it's easy to speed up chemical reactions I can increase temperature I can add acids in a laboratory right I can speed up chemical reactions but these biological catalysts allow us to speed up chemical reactions without altering homeostasis if we're gonna go for a run you can't crank your core temperature up to 140 degrees you're dead or you can't you know you don't want to drink the hydrochloric acid or something before you workout we can't use acid we can't use temperature in the same way to speed up chemical reactions at least not to any great degree so we have these biological catalysts these protein based enzymes that speed up chemical reactions without altering our homeostasis without without damaging us in the process I think that's very very important all right so the key things we've noted here is enzymes are protein they have the a sending today they work by lowering activation energy that's the most common thing you're going to hear they have turnover rates of up to 20,000 reactions per second that's unbelievable think about one Mississippi there's a hydrolytic enzyme somewhere that just disco formed 20,000 reactions they speed up chemical reactions up to a billion times faster and then a biological catalyst allows us to do all this without destroying us in the process without damaging homeostasis all right other key things to note here they are usually very specific when you think of enzymes think of locks and keys but you know that the key that I use to get into my car is only gonna start my car just so like the enzyme enzymes sucrase for example it's going to break down sucrose but it won't break down lactose the enzyme lactase will do that so there they're specific that's a Keith a few more things here a lot to know about enzymes but what are the kind of things that are gonna influence how enzymes work so here I just got a different picture here of an actual of an enzyme working what they do is they take this chaotic world and they organize and control it and that's how they lower activation energy they make these random processes more likely to occur much more likely to occur but the key things that will influence if this enzyme sitting here will actually do its job is going to be pH substrate concentration and temperature so enzymes are proteins and just like other proteins if you change the pH too much or change the temperature too much they will denature they will fall apart so that's why all enzymes have a pH range where they can work in a temperature range where they can work this is why I think like a fever if you get a really high fever for too long or your patients get really high fevers are too long that can lead to organ failure what's really happening is their enzymes are starting to denature and their enzymes aren't working and without an enzyme you don't have a metabolism and without a metabolism you don't have life so that's really the cause of death because of a high fever or a condition where someone's pH drops too low is going to be their enzymes are unraveling substrate concentration that just means that the more substrate there is around the faster enzymes will work until they reach a saturation point where no matter how much more substrate you should that shows up that I'm working as fast as I can I can't do any more so there's a few more interesting things to note there what else but enzymes I have one more thing I wanted to show you this is another another picture of the same thing now instead let me go back here this is this is an enzyme that's going to be breaking something apart as you see there the substrate is is larger and it's broken down into smaller products here's an enzyme that takes smaller reactants and builds a products this would be a synthetic enzyme but then what still has the same specificity everything else is the same but the last thing I want you to note is that many enzymes cannot work on their own they need a cofactor or a coenzyme in this situation the protein portion is called an a po enzyme once you've added the cofactor or coenzyme it's now a holoenzyme I don't use those terms much I think it's very important to know what these cofactors or coenzymes are cofactors are going to be inorganic these are primarily going to be minerals so you think think why do I have to eat vitamins omit or well minerals are going to be the cofactors that power these enzymes a good example is you need zinc for the enzyme DNA polymerase to work if you're gonna build new DNA you need zinc and then coenzymes are going to be vitamins almost all of them are going to be your vitamins you need niacin to make nad riboflavin to make fadh2 these are going to be electron electron carriers but they're going to be these enzymes so that that's what a cofactor in a coenzyme are they turn they basically activate or turn enzymes on cofactors being minerals coenzymes being vitamins okay that's a lot I think that's everything you need to know to have a foundational understanding of enzymes and just understand that life would not be possible without them so make sure you think your enzymes have a wonderful day be blessed