 Let's talk about proteins since I was already in my Google slides. I just decided dude I'll show you the subunits for proteins right now Proteins all of them are made from amino acids There are 20 amino acids that are used to build the proteins in our body And you can think of it almost as if there's an alphabet of or there's 20 different Legos that you can use to build all the things all the muscle things all the receptor things all the hormone things all the neuron things I Mean it'll be really interesting to see what you think at the end of the class when we get all the way through it Which of these bio molecules did we talk about the most? I'm gonna throw down some money that says we're gonna talk about proteins the most At the very least I'll throw down right now for physio We definitely talk about proteins the most in physio and all of them are built from these amino acids Now I am gonna go back to my notes and one more time I am totally punting on that chart So you go back and fill in that chart based on but I just don't have enough room for what I want to say here our proteins the subunits are amino acids and If we talk about the Function of proteins we could spend a million years just talking about What they do? Um, and the shape and maybe this is the thing that just this is the take-home message the shape of of a protein determines its function And this is something I'm just gonna take a second to Put little hearts around this and tell you we'll draw and maybe a flower So that you remember this fact The shape of a protein its structure determines its function I don't know if I've said this already in this class But if I haven't it's not the last time you're gonna hear this in all of your biology classes. It's a theme of the biological sciences that the Structure of the thing the structure of the organ the structure of the molecule Determines its function its shape Let's it do the thing it's gonna do and proteins They're sensitive little critters and they're powerful little critters and I say they're sensitive because guess what? pH Hydrogen ions what who knew that one little proton could be so powerful hydrogen ions can change the shape of a protein and in Can make it not work anymore That's why your pH in the human body is actually maintained between like I don't know 7.38 to 7.42 Not seven 7.38 to 7.42. So if you go down to 7.3 you are considered Too acidic your blood is too acidic and your proteins start to change shape Your proteins start to change shape and you stop functioning the way that you are supposed to function Which is bad? You don't want that to happen. So pH is super important because of proteins now let's talk about the structure because there are four levels of protein structure Primary structure of a protein is just the sequence of Amino acids so remember that list of 20 amino acids I had you could just throw those out in a line and the sequence that you tell me is the primary structure of that protein all Proteins have a primary structure. They have a sequence of amino acids that they're made of Some part like the biggest protein is a protein called Titan and it's in your skeletal muscle organs and It has like I had 30,000 amino acids in one protein like it's absurd how huge that protein is hemoglobin Very important protein. I think it's hemoglobin. Oh, no, it was insulin insulin is a protein hormone a peptide hormone and it has 51 amino acids that make it up if we listed out all 51 We'd have the primary sequence of the primary structure for insulin if we listed out all 30,000 We'd have the primary sequence for Titan Don't worry. We won't be doing that your secondary structure your secondary Structure of a protein is actually okay, and this is really interesting. So you imagine a string of amino acids well, sometimes those amino acids are attracted to each other and the the string sort of folds and it can fold in like little accordion shapes or a little helix shape But the actual string Does these little folds and that is your secondary structure? I'm just gonna write alpha helix or Beta pleated Sheet that doesn't mean a whole lot to me except those are some examples of the ways that that sequence of amino acids can fold To create that secondary structure Well, your tertiary structure. I'm gonna write that one out because I would not think that worked tertiary structure is That secondary structure folds on itself again Folds on itself again, I Do have a hard time. Maybe I'm out of practice for writing and talking at the same time. I Have a hard time I go, okay alpha helix beta pleated sheet We pleated and we helixed and then we fold those up and I am and then I Create a thing that has even more sort of globular Structure and that would be my tertiary structure and there is a quaternary structure and that's when more than one protein subunit Combine So you can end up with and this is hemoglobin has multiple subunits And that's a protein that carries oxygen in your blood cells red blood cells when those different subunits those different tertiary folded Strings of amino acids combined together and have a new structure. That's quaternary structure of the proteins Now you might be like, oh my god, seriously like what why do we need to know all of that? Well our next biomolecule is nucleic acids and Hopefully you've heard of DNA DNA provides the instructions for building all the proteins in your body and those proteins. I'm telling you All the other stuff is cool. I mean I got a little of the fat along with everything else, but protein That's what that's what's doing the work of being alive Carbs are providing the fuel to make it happen. That's are storing it and keeping us waterproof. Thank you very much But proteins those guys are doing all the work. So let's look at our last category of biomolecules and then we're going to say good night