- Nucleic acids, lipids, and carbohydrates questions
- Nucleic acid structure 1
- Antiparallel structure of DNA strands
- Saponification - Base promoted ester hydrolysis
- Lipids - Structure in cell membranes
- Lipids as cofactors and signaling molecules
- Carbohydrates - Naming and classification
- Fischer projections
- Carbohydrates - Epimers, common names
- Carbohydrates - Cyclic structures and anomers
- Carbohydrate - Glycoside formation hydrolysis
- Keto-enol tautomerization (by Sal)
- Disaccharides and polysaccharides
Lipids as cofactors and signaling molecules
Created by Ryan Scott Patton.
Want to join the conversation?
- Does anyone know which specific video(s) Jay is referring to on steroid structure and function that he advised to watch here?(6 votes)
- I think he means the section titled Biological basis of behavior: Endocrine system(2 votes)
- If I take ibuprofen when I get a headache, does that mean there's inflammation in my brain that's causing my brain to hurt?(3 votes)
- Theres many different theories about headaches and wha the actual physiology behind them is all about. One theory is that somewhere throughout your head you have arteries that become inflamed causing an increase in intracranial pressure therefore causing the pain-like symptoms (Ex. Temporal Arteritis, google it). So therefore in a nutshell like you say the Ibuprofen's anti-inflammatory effects may reduce this inflammation helping relieve the headache. Other theories are due to over active pain nerves in the head, tension and cramping of muscles, and a whole lot more. Its a growing field of knowledge.(2 votes)
- So non-hydrolyzable lipids are lipids that cannot be broken down with water, and hydrolyzable lipids are those that can be broken down with water and are made up of multiple distinct smaller molecules?(2 votes)
- Why do cells prefer to hydrolyze carbohydrate polymers rather than liquid polymers?(1 vote)
- Well if I understand correctly fat is essentially a goldmine to our bodies in the sense they yield more energy in terms of ATP in comparison to any macromolecule such as proteins and carbohydrates per gram. Due to this case, our bodies rather hydrolyze carbs first before they start resorting to energy rich lipids for energy.(1 vote)
- Don't prostaglandins increase platelet aggregation? And this is why taking NSAIDs decreases blood clotting?(1 vote)
- I've been doing some other research, and I can't find anywhere else that says that Steroids and Fat-Soluble vitamins are types of prostaglandins. They seem to be totally separate types of molecules. Is that true? Or is this just another way of thinking about it?(1 vote)
- You've got it a bit backwards. As the title of this video might suggest, the major category of discussion is the lipid class of molecules. Prostaglandins (1:59), steroids (3:44), and fat-soluble vitamins (5:23) are all lipids. The first two function as signaling molecules, vitamins function as signaling molecules. Does that help?(1 vote)
- I heard in the video in about6:00that some vitamins are needed to be consumed, but I heard that vitamin D is actively made through sunlight by the body. Or did I misunderstand?
Many thanks!(1 vote)
- Yes, we can make some Vitamin D, but it often not enough.
This is particularly true at higher latitudes (closer to the earth's poles) during the winter when days are short, light levels are low, and heavy clothing is needed for protection from the cold.(1 vote)
- So sometimes I go for a pretty long bike ride and when I do that I usually end up kind of getting an ache in my lower back or in my neck from being humped over the handlebars for a really extended period of time and when I do that, if it's really bothering me, sometimes I take some medication for it. So some medication, and the medication that I prefer to take would be an NSAID. So an NSAID, and you might have heard of some common NSAIDs. You might even take them, too. Aspirin, for example, is an NSAID, aspirin. And ibuprofen is another example, sometimes that's called Motrin, but it's the same thing. Ibuprofen. But these drugs, they help reduce that ache because that ache is caused by inflammation in the muscles of my lower back and in my neck. And these are anti-inflammatory drugs. In fact, NSAID stands for: Non Steroidal Anti Inflammatory Drug. And part of the reason why these medications stop that ache is because they stop the production of prostaglandins. Prostaglandins. You see, prostaglandins are lipid molecules that help signal inflammation. So if I can stop these prostaglandins then I can stop the kind of further, and to some extent, the past production, of this inflammation and it's affect in my body which would be the ache. And prostaglandins fit into a larger class of lipids called non-hydrolyzable lipids. So, remember that we broke lipids down into hydrolyzable and not hydrolyzable. Hydrolyzable are the lipids that can be further broken down into smaller units through hydrolysis reactions, and then we have the ones that can't be. So prostaglandins fit into this kind of category of not hydrolyzable lipids, and we talked about how the hydrolyzable functions might include energy storage and kind of this structural function, while the not hydrolyzable lipids, their main function revolves, at least in our body, around signaling. So signals just like the prostaglandins signal this inflammation up here. So I think I have a picture of prostaglandins that I can kind of fade in for us and this would be the prostaglandin PGI2 here. But prostaglandins are probably the most notable of a group of biologically active compounds called eicosanoids, so let me kind of write that in here. Eicosanoids. And eicosi is actually Greek for 20, so these are compounds that have 20 carbons. And you can count, if you want, the carbons in PGI2. But eicosanoids are kind of famous for being local mediators which means they signal an effect in their immediate environment. And prostaglandins are probably the most noteworthy of these eicosanoids. So an example of the effects that prostaglandins stimulate would be inflammation, we covered that, they also lower your blood pressure, prostaglandins, let's see, they lower your gastric secretions, they inhibit platelet aggregation, but there are a lot of signals, or affects at least, that are signaled by these prostaglandins. So they are a signaling lipid. Now, another signaling lipid that are kind of pretty famous, let me pull in a picture of them, are steroids. I'll write that in as well, steroids. So steroids are a tetracycline lipid which means they have kind of four rings, four cyclic rings, and you can see this in the picture here. Maybe, I'll get a darker color. So we'd have one, two, three, and then four rings, and in each of these steroids, the four rings three of them are six membered rings, and the fourth is this kind of five membered ring. They all have this four ring structure and then they differ in their little substituents but and I've already done kind of an in-depth series of videos on the structure and functions of steroids, but I'll keep it brief here and just kind of mention that steroids are another non-hydrolyzable lipid and that have a signaling affect in our body so cholesterol would be a steroid. This one right here is actually testosterone. Testosterone, and this one is progesterone. Progesterone. And these are examples of sex hormones in our body, they signal things like puberty, for example, and you have some other steroids like the corticosteroids cortisone, and aldosterone. But if you want to hear, I guess, a lot about steroids, you should definitely check out that other playlist of videos. But the last non-hydrolyzable kind of signaling lipid that I want to talk about are actually vitamins. So fat soluble vitamins. And I suppose I mis-spoke a few minutes ago when I said that non-hydrolyzable lipids all have this signaling function because fat soluble vitamins really function more as co-factors, so co-factors, which means that they help some enzyme in our body perform a function. Our cells don't make these compounds, so we have to ingest them to help these enzymes perform their function. And there are four fat soluble vitamins, we have A, D, E, and K. And I think I've got a picture here I can pull in for us. This one right here is A, and vitamin A is also called retinol, and it's needed for light sensitivity in our vision as well as kind of healthy mucus membranes. It has a couple different functions in our body. We have vitamin A, we also have vitamin D. Vitamin D helps regulate phosphorous and calcium metabolism. So deficiencies can cause a number of different bone diseases like rickets and osteoporosis. So we got A, D, we've got E right here. Vitamin E is an anti-oxidant that help protects our neurological function. And then vitamin K at the bottom. Got Vitamin A, D, E, and vitamin K regulates the synthesis of prothrombin which helps our blood clot. So a lack can cause some pretty serious bleeding issues. And I don't know why it kind of sticks in my mind, but A, D, E, and K are the fat soluble vitamins and they fit into, they fit into that broader category, again, of non-hydrolyzable lipids. Non-hydrolyzable lipids which primarily function as signaling molecules, and I guess for the vitamins as co-factors. Co-factors as well. All within kind of that big category of lipids.