the final one is lipids and lipids remember only group together because they share the characteristic that they are lipid that they hate water they're hydrophobic our main lipids in our diet are triglycerides which is glycerol and three fatty acids so here's our glycerol if we add a fatty acid to it we do it through dehydration synthesis so we get a monoglyceride plus water we add another fatty acid to it diglyceride in two waters and then when we add the third we get a triglyceride and three waters so it's the same dehydration synthesis in order to remove them we're going to add the waters back and that's hydrolysis okay so remember those squiggly legs are because we have carbons that are that make up hydrocarbons that make up the fatty acid tails and that's where it attaches to the glycerol but these carbons are going to have four bonds so if they have no double bonds all single bonds they're going to have a hydrogen every single place possible this would look like each carbon would be a point and that's what that would look like so here would be a carbon here would be a carbon three four and then a point at the end is five five carbons so that would be a five carbon this and this are the same thing okay now if so this would be a saturated fat fatty acid it's saturated with hydrogens saturated fats are solid at room temperature they include animal fats like lard and butter and also [Music] tropical oils like coconut coconut oil by the way is not good for you i don't care what that nude nick dr oz says coconut oil is more saturated than butter and saturated fats aren't the way to go so coconut oil palm oil and cocoa butter see the cia okay these are all saturated they have the maximum number of hydrogens they are saturated with hydrogens now if on the other hand we had some double bonds rather than having it completely saturated if we had carbon carbon double bond with a carbon carbon okay that means that this guy would have two less hydrogens than it would otherwise have because each carbon forms four bonds one two three four that got one two three four for that guy so if it has a double bond this would be monounsaturated monounsaturated if it has multiple double bonds it's polyunsaturated and polyunsaturated fats are the best ones okay and that would include like olive oil and things like that all right so we also know and steroids are all made from cholesterol so cholesterol is another type of fat that we have in our diet we get cholesterol from exogenously okay exogenous that's from our diet and because we're animals we also make cholesterol okay now to digest fat we need fat okay let's see okay so lipases are the enzymes that break down lipids okay but in order for the lipase to break down the lipids we have to corral these suckers and what does that mean well like i said we need fat to break down fat when you're washing dishes in the sink if you're washing some greasy pans you know that the fats start to all gather together and you get these pools of oil on the surface instead of tiny little dots they glom together and that's because these guys just like phospholipids in our membrane these guys want to hide their tails because they are the tails are hydrophobic and you get bigger and bigger globs of these fats with them all hiding their tails well what's a lipase to do if it can't get to the tails if it can't help break these guys down what happens is we use bile okay you make bile in the liver you store bile in the gallbladder and bile helps you digest fat bile is a breakdown product as well as a component that's involved in digestion of fats it's a breakdown product of red blood cells because it includes heme okay includes the bilirubin and so what happens with bile is bile emulsifies fat and then the lipase can work on it so you have these really big globs of fat they're all sort of it's sort of like a herd of antelope all right and you're the lion and you've got to pick one of them off for dinner well that's what bile does bile is going to go and surround this guy and that separates him from the herd and that's called emulsification now bile is going to be hydrophilic on the outside and hydrophobic on the inside just like these guys are so that it can surround these hydrophobic structures hydrophilic on the outside so that it can be in a watery environment hydrophobic on the inside so these guys are attracted to it but it plucks these little guys off one by one and coats them so now they're separated from the herd and now the lipases can can work on them what the like pieces do is they are going to take that and make it into a monoglyceride and two fatty acids so they're going to use lipases they're going to use water to break those two fatty acids off the triglyceride and then what's really weird about this is okay so here is an absorptive cell okay and this cycles up to the absorptive cell and it takes that monoglyceride and two fatty acids in and it reassembles it into a triglyceride and then it's going to put a protein coat around the outside and put it out into the lymphatic capillary because remember the fats are too big to go into the bloodstream they have to go into the lymphatic capillary so we emulsify it with bile biola is going to pick these guys off pick them off from the herd separate them so that the lipases can work on them and remove those fatty acid tails and then when it is absorbed into an absorptive cell it's going to be reassembled and reassembled into a triglyceride and then that is going to get a protein coat around it it's going to go into lymphatic capillary and and then from there travel through the lymph until it enters the circulation at the level of the subclavian vein okay so that is the lymphatic capillaries called a lacteal and the stuff in it is called kyle c-h-y-l-e and these guys are kylo microns when they go into the lymph they're called chylomicrons and that's how lymph uh that's how the lymphatic system absorbs fats okay it kind of seems weird you know go through this all this hassle just to break them down just to reassemble them but that's the way it goes now the bile has cholesterol in it and one thing that i talked about insoluble fiber in your diet being stuff you can't digest soluble fiber is another type of fiber and you find soluble fiber in oats in the pith that's the the white stuff of oranges uh you find it in apples find it in beans and what soluble fiber does so this layer out here has some cholesterol in it is it will grab on to this okay so this has delivered its payload and now this is going to go into your blood and be recycled back to your liver well soluble fiber grabs onto this and forms a gel and removes it through your large intestine removes it from your circulation removes it from your gi tract with the feces so soluble fiber removes the bile cholesterol in the feces it grabs on to it and moves it with the feces and so therefore in order to digest fats you need cholesterol and so what does your liver have to do well before it makes more cholesterol it's going to see if there's any available and it causes the liver to remove cholesterol from your bloodstream to make more bile and so if you've heard that eating oats is heart healthy like oatmeal or cheerios it is okay because you are decreasing your blood cholesterol by allowing this soluble fiber to take the bile with the associated cholesterol out of your body so that your liver has to make new instead of recycling it and to do that it has to remove cholesterol from your blood so this decreases your blood cholesterol so every morning just about for breakfast i have a bowl of oatmeal with apples make sure that i get all my soluble fiber my blood cholesterol is just terrific and i would advise all of you to try to get more of these in your diet oranges apples beans oats and there's some other things too but oats are really really good for this soluble fiber to help keep your blood cholesterol down okay