 In this module, we understand the chemistry of hormones or the heading of the biochemistry of hormones. So biochemically, the hormones that may be a different kind. It may be proteins, it may be the derivatives of amino acids or maybe the steroids. So these are the three categories of hormones that we come across. So proteins, it may be polypeptides or its example is insulin. Insulin is about 51 amino acids in two chains which are held together by this disulfide linkages at specific sites. So this is a hormone which is the protein in nature, the protein in nature or polypeptide in nature. Then there is amino acids and its example is TSH, that is thyroid stimulating hormone. And the third category is steroids. Its example is sex hormones and adrenocotico cortical hormones. So now we will look at the formula of their chemistry and then we will see what are the proteins. What are the derivatives of amino acids and how are the steroids, what is its chemical structure. And there are very few, very few which are fatty acid derivatives. And these fatty acids are like post-aglandins. So there are four types of hormones, chemically, biochemically. We can categorize these hormones into four different categories. The proteins, then the derivatives of amino acids, then the steroids or fatty acid derivatives. Or fatty acid derivatives, post-aglandins. They are synthesized in the walls of blood vessels. They regulate the concentration of smooth muscle tissue and they are also involved in inflammation. So they are the derivatives of fatty acids. Now we will look chemically. So these are polypeptides. Its example is a long chain of amino acids that makes the water soluble. It is water soluble polypeptide which is insulin. Insulin, we will discuss in detail what is the role of insulin in our body. And after that there is lipid soluble. So water soluble is lipid soluble. These are steroids. And this part of it is called as nucleus chemically. It is a cyclopentanopahydro phenanthrene nucleus. And when this part, these are some additional atoms or group of atoms, so it is called as steroid. So this is not water soluble. These are usually lipid. And steroids, you are familiar with these steroids. This is created by steroids in every cell membrane. And without this, our cell which is called as flexibility does not remain. And it plays a very important role. And after that there is epinephrine. This is epinephrine which is the derivative of amino acid. This is also a thyroxine which is again a derivative of amino acid. So these are the different amino acids that group together to form a chemical messenger which is a very effective chemical messenger. And these are some other examples of steroids. There are three. Six-sided rings, then the five-sided ring. So these are four molecules that form a nucleus. Now there is a progesterone. You know there is a female hormone called progesterone. Then there is a estradiol. This is a precursor of a lot of steroid hormones. The estradiol. And this is also one, two, three, four. One, two, three, four. And along with this, this is a methyl group. So this is the estradiol. This is again, there is a steroid hormone. Then the testosterone. Similarly, this is one, two, three, four. So these are four very important parts. If this is removed, this is removed. So obviously testosterone will not behave like testosterone. Its chemical composition will change. Its properties will change. So this is not just one ring. In fact, if any of these are not radical, then its properties will change. So from this, these chemicals are very important. Its structure, especially in hormones. So these are the steroid hormones. Then this is a post-aglandin structure, which is derivative of fatty acid. And in this, we are looking at a five-sided molecule. Five ring structure. This is the five-cornered, you can say the structure of a molecule. And the long chain of a carbon, hydrocarbon, which is usually called fatty acid. So this, along with this, that makes a post-aglandin structure. In this, if any atom or group of atoms, if it is deleted, if we remove it in some way, then its structure will not change. So from this, the placement of these atoms or group of atoms is very vital for the activity, for the functioning of a particular molecule. So this is all about the hormones. So in short, we can say that these are the five categories of hormones. And these mooclyph glands, they will be producing different types of hormones and they will be having their own very specific effects in the body. So this is all about the biochemistry of hormones.