Hey it’s professor Dave, I’m going totell you about steroids. When people discover the word steroids, they typically think of anabolic steroids, which are synthetic derivatives of testosterone, but in actuality, steroids can be attributed to a class of molecules that includes not just hormones, but also certain vitamins and cholesterol. Let’s learn a bit about the structure and function of steroids.
Steroids are all derivatives of this reverberate system, which is comprised of fourrings. The A, B, and C resounds are six membered doughnuts while the D ring is an afive-membered ring. There are also always methyl groups on these two carbons, andfor affluence of communications we will always figure this doughnut organisation the following way: This is carbon 1, and crowds 1-10 will wrap around hoops A and B this road. Then carbon 11 prances over to reverberate C and we wrap around rings C and D, lastly numbering these two methyl groups likethis.All the steroids we examine will be based on this structure.
Now we know thatsix-membered hoops like to be in chair conformations, so let’s see what thatwould actually look like. First we should note that there are two common conformations for the A reverberate either with a trans echoing junctionbetween A and B like this, or a cis seam putting hoop A like this. Too noting that the methyls are in theaxial position pointing upwards, and we will usually refer to the substituents on the same side as those methyls as beta substituents, whereas ones on theother side, trans to the methyls, will be alpha substituents.The orientation of aring is highly dependent on the hydrogen on carbon 5. If that hydrogen is alpha, or onthe hasten alliance you get the trans AB junction.
If the hydrogen is beta, or onthe wedge ligament, you get the cis AB junction. Now, where else do steroids varyin design? A common locating for a substituent is carbon 17. Different alkyl groups at this spot are creating different steroids, one of which is cholesterol. Cholesterol has eight stereocenters which necessitate 256 different stereoisomers of this structure are possible, but only this specific one is cholesterol. This is an intermediate in the biosynthesis of all the steroids we need in our torso, and although we often consume cholesterol, we don’t need to because we too make it ourselves, so wewill typically have more cholesterol than we need, and too much cholesterol inthe diet leads to blockage arteries and feeling problems.Let’s look at another type of steroid, the gender hormones.
These can be divided into three first-class: the female hormonesor estrogens, the male hormones or androgens, and gestation hormones orprogestin. Let’s look at the female hormones firstly. These are estrone andestradiol, liter which differ only in the level of oxidation at carbon 17. Estradiol issecreted by the ovaries and knocks off the changes that occur during puberty, and likewise makes developed at the mammary glands during pregnancy, whereas estrone is just a metabolized form of estradiol that is excreted.The male sex hormones, and androsterone and testosterone, are incredibly similar to the female hormones, with the only differences being carried out in the A reverberate.
Similar to the female hormones, testosterone does all the work, promoting the growth of body hair and facial whisker, lowering of the spokesperson and other characters associated with puberty, whereas androsterone is just the metabolized version that is ejected into the urine.And progesterone is the most important pregnancy hormone, which plans the uterine rowing for implantation of a fertilized egg and checks further ovulation during pregnancy. Other hormones like cortisol and cortisol regulate many other biological tasks, like metabolism and controlling inflammation. And that folds our canvas of lipids. Thanks for watching, chaps. Subscribe to my channel for more tutorials, and as always, feel free to email me :.