 And this video we're going to talk about protein structure. So obviously proteins are important. I'll give you some interesting facts in just a little bit. But the structure or shape of a protein is critically important to its function. That's why I generally think of proteins, I think of them like keys, right? You can have a key. If the key doesn't have the right shape, it's not going to be able to do its job. So structure determines function is very important all across human anatomy and physiology, but especially so with proteins. If a protein loses its shape, it loses its function. So a term real quick before we jump in is denaturation. Something that causes a protein to denature will cause it to lose its shape. That can be high heat, acids, et cetera. So I won't go into detail now, but I want to make sure you hear that word denaturation. If you denature a protein, it loses its shape. When you cook an egg, that's what happens. You denature the proteins that are in the clear part of the egg, and that causes them to change and they become white. So here we're going to talk about the primary, secondary, tertiary, and quaternary structure of proteins. Before we do so, just a few more facts about how important protein is, right? We talk about carbs and lipids are basically fuel sources. But proteins are the building material of the human body, right? You are, besides water, you are protein. Protein makes up 45% of your body. Collagen is actually the most common protein in your body. It's all over the place. There are 100,000 or more, give or take, different proteins in the human body. You can make an argument that there are 10 billion proteins per cell and you're made of 37.2 trillion cells. Our genes could potentially be able to make two million or so different types of protein combinations. Some estimates say that your body has to produce about 300 quintillion proteins per hour for you to survive. So protein is a massive, massive deal. So let's go ahead and look at the primary, secondary, tertiary, and quaternary structure of proteins then. The primary structure, as you see here, is just the sequence of amino acids. So as we'll learn later, our genes determine the sequence of proteins that are put together when the proteins are being built to make you. So the primary structure is the sequence of amino acids. If there's a mutation and you have the wrong code in a gene, then you'll have the wrong amino acid and that'll impact the primary structure for protein. Good example there would be hemoglobin with sickle cell anemia. There's a gene mutation that causes the wrong amino acid structure, changing the structure of a protein, hemoglobin, which changes its function. So just remember, primary structure is the sequence of amino acids. Next we have the secondary structure I call these local changes in shape. The two types of local changes you see in shape that make the secondary protein structure would be the alpha helix and the beta pleated sheet. So the primary structure is the sequence of amino acids. The secondary structure are local changes in shape or local shapes. And they're going to be the alpha helix or the beta pleated sheet. The tertiary structure is the three dimensional structure of the protein. So obviously very important because we just said the shape and structure of a protein is critical to its function. This is where you get that lock and key analogy. If the protein has the right structure, then it's the right shaped lock or right shaped key and will do its job. If it has the wrong three dimensional structure, it can't do its job. If I try to put the key for my front door and somebody else's front door, it's not going to work, right? I used to have a lock at an old house in Liberty City where I had to put the. So the lock, the key was a little bit misshapen, but it still worked. I had to put the key all the way in, I pulled it out a little tiny bit, turned it one direction, then when I turned the other direction it would work. So there's an example of a key that still works but not very well. So sometimes we do have proteins that are slightly misshapen that can still do their job, just not super effectively. So primary structure, sequence of amino acids, secondary structure, local changes in shape, tertiary structure here, the three dimensional shape of a protein. Now not all proteins have this, but the quaternary structure is when you put more than one polypeptide chain together to form a larger structure. So the quaternary structure here, this is hemoglobin. Notice that there are four protein chains put together, they're fused together to form hemoglobin. So that would be the quaternary structure. So primary structure, sequence of amino acids, secondary structure, think local changes in shape, tertiary structure, the shape of a protein of a polypeptide, quaternary structure when you need to put more than one polypeptide chain together to form a larger complex protein. All right, so that is the structure of proteins and how, and how important it is to their function. I hope this helps. Have a wonderful day, be blessed.