 Hey everybody, Dr. O here. Welcome to chapter six. This is our last video about the macronutrients. We've covered carbs and fats and now we're moving on to proteins. So protein is super super important and I'll explain why but when it comes to the diet I generally focus on you know there are like really good carbohydrates and really bad carbohydrates. We have soluble fiber and we've got just added sugar. There are really good fats and really bad fats. You got like your omega-3 fats and monounsaturated fats being really good and things like trans fats being really bad. With protein it's kind of like there are good and great proteins. As long as you're getting what are called complete proteins where you're getting all the amino acids, all the building blocks you need, the quality of the protein it matters but not as much. For example you know people think that you need a whole bunch of animal protein if you want to be a bodybuilder or a weightlifter or getting stronger but studies show that vegan diets as long as there's enough protein and there does have to be slightly more because the quality of the protein isn't as good. Eating a plant-based diet doesn't impact these gains as much as people think. So it's like there are good proteins and there are great proteins. Alright let's go ahead and dive in. So the icebreaker. Most of us recognize meat as a source of protein. Our bodies use to build cells including muscle cells and those in our bones, skin, hair and elsewhere. What is your go-to source of protein? If it were not available what else could you eat to consume protein? How many alternative sources of protein can you name? So yeah I think most people when you ask them what are foods that are high in protein you would mainly say animal products, you've got your meat and you've got your dairy and you've got your eggs. All great sources of protein, all complete proteins which are really good and I'll talk about what this term complete means as we move forward. But there are lots of other places you can get protein. I mean you do, you get some protein in grains and beans, legumes, nuts, seeds, those are all great protein sources as well. You've got things like tofu and that and then you can get protein from supplements as well as on top of food. So there are lots of different places for you to get protein. Another like so examples of complete proteins that aren't animal products would be soy protein and quinoa. So Q-U-I-N-O-A. I called it quinoa for a couple years until I was told that it is called quinoa. So all right so those are some examples of alternative proteins. But this goes you know think about what we're made of right? We as humans we are bags of 50 to 70% water and then we're you know we obviously have water and fat and bone and all these types of things. But you know once you remove these are fuel sources like glycogen and fat and you remove water right? We are you know protein is what makes us us and protein is what makes us unique right? Because our genes code for our proteins and that's what makes me, me, and you you right? We're very very similar because we're humans but our variations what makes us different is that different proteins are being produced which is why maybe our hair color is different or eye color is different skin color is different the amount of enzymes we have as far as detoxifying alcohol or digesting sugar all these things are different because of the proteins that are inside of our body. So yes we will look at the many functions of protein right? When you think of protein you probably think of your muscles and there's nothing wrong with that but but contracting muscles and moving our body through space is only one thing that protein does. You know the first thing I think of with proteins in the body is enzymes and enzymes are basically the catalyst that power our metabolism. So all right we'll look at all that. Learning objectives so what should be able to know at the end of this chapter? Recognize the chemical structures of amino acids and proteins so amino acids are the individual building blocks that make our proteins we'll look at those. Summarize protein digestion and absorption that one's pretty straightforward especially compared to fat. Describe how the body makes proteins and uses them to reform various roles we'll cover that list I just started mentioning. Explain the difference between high quality and low quality proteins including notable food sources of each that's where we'll talk about complete proteins versus incomplete proteins and high and low quality proteins and what that actually means. Identify the health benefits of and recommendations for protein and I will sprinkle in a little bit of extra information here because I really really do think that protein is no matter what you think your diet should look like you know whether you want to be a high carb person a low carb person a keto diet this that if I'm helping someone plan their diet to me it's like let's get let's get your protein taken care of and let's get your fiber taken care of and let's make sure you're eating an appropriate number of calories and after that you really can just kind of fill in the gaps to make sure you're getting your vitamins and minerals and the fat you need and the carbs and all that kind of stuff so so protein is a really big big deal. I also want to talk when it's when it's relevant later I want to talk about something that I'm a real firm believer in called the protein leverage hypothesis which shows that living animals like us we basically eat until we meet our protein needs so if you're eating a diet that's too low in protein your body will send signals that will lead you to overeat to make sure you're meeting your protein targets that's one of the reasons that I think that high protein diet is is satiating meaning that it keeps you full longer and you're less likely to overeat on a diet that has some more protein so generally speaking for most people I err on the side of putting them on the higher end of protein recommendations instead of lower but that's not medical advice just my my opinion. Okay the chemist view of proteins so proteins what makes them unique is they have they have carbon hydrogen and oxygen same as fat same as carbohydrates. Remember fat and carbs are just different arrangements of carbon hydrogen and oxygen that's why they're both fuel sources they're like the hydrocarbons that you put in the fuel tank of your car but what makes protein unique is the nitrogen you see there on the amino group it has nitrogen so nitrogen is the fourth most common element in the human body and the only place we get it is from protein we're exposed to nitrogen all the time right almost 80% of the area breathe is nitrogen but it's a it's a worthless form for us of atmospheric nitrogen organisms in the soil that are called nitrogen fixers or fixators they take this atmospheric nitrogen and turn it into the nitrogen that we need to survive and then we get the nitrogen from eating protein we get it from eating plants or eating the animals that ate those plants and that's how we turn this or that's how microorganisms help us turn this worthless nitrogen into the fourth most important or fourth most common element in the human body right yeah so there so what are amino acids they all look the same except for that white box there the side group they all have a central carbon with the hydrogen off of them they all have the amino group where the nitrogen is they all have this acid group which you see on the green on the right hand side and then each of our 20 amino acids are going to have a different side group so some are going to be hydrophilic some are going to be hydrophobic they're you know they're they're they're different level digestibility etc etc what makes them different is that side group alright so which statement about amino acids is correct non-essential amino acids may become essential under certain conditions so so non-essential amino acids so that remember essential amino acids must be consumed because your body can't make them or can't make enough of them so you have to eat the essential amino acids non-essential amino acids can be made in the body and I'll show you in this this lecture I'll show you how that happens you can basically turn and you can turn one amino acid into another and that's how you would build the non-essential amino acids that you need I think it's best to make sure you have a constant supply of all of them but but there are but sometimes what's what's normally a non-essential amino acid can become essential and those are called conditionally essential amino acids so think about maybe during periods of high stress maybe you have a certain genetic condition like phenyl ketoneuria which maybe you've maybe never heard of that but if you ever looked at a diet soda there'll be a warning on there that people that have phenyl ketoneuria should not consume it because it has a lot of phenylalanin in it and there and they can't deal with it so there so there are there are genetic conditions and then maybe periods of high stress or illness or injury where some of the non-essential amino acids become conditionally essential so let me read what that means conditionally essential amino acids are those that are usually non-essential but under certain conditions must be supplied by the diet so again I think just getting a broad spectrum of amino acids in every meal is the smart thing to do and that's because we don't we can't store amino acids right we people talk about this amino acid pool but I've I've never seen it I don't know where it is in the human body right we just we constantly have this flux where there are some there are amino acids available throughout your body but you don't have an area to store it we use proteins and we build muscles and the protein portion of bone and all that with muscles or with protein sorry but but we don't have a pool that we can store like we can store carbs as glycogen we can store fat as fat we don't we can't store amino acids okay so here you see the amino acids and you have the list of essential and non-essential amino acids so we need all of them notice there are 20 there are other amino acids that are that are in the world but they're not in the proteins that we consume or that we need that we that we build so that these are the only 20 we care about so you may see different numbers like you see down here at the bottom things like taurine and ornithine those are not they're not any that we care about so we're just looking at these 20 amino acids so these are the 20 building blocks that build every protein in your body right so your genes code for different combinations of these amino acids then your body puts them together and that's how it builds proteins that's how it builds hemoglobin it's how it builds the protein in your muscle muscle it's how it builds collagen all of these come from these amino acids so the essential amino acids I'll just say them so you know how pronounce them we have histidine isoleucine leucine lysine methionine phenylalanine threonine tryptophan and valine and then on the non-essential amino acids we have alanine arginine asparagine aspartic acid cysteine glutamic acid glutamine glycine proline serine and tyrosine so that you know obviously they're all important but the non-essential ones can be can be created in the body and the essential ones must be consumed just looking at a few examples here let's see valine leucine and isoleucine those are what are known as your branched chain amino acids it does there they've been used for in strength training for years to try to help people recover from exercise and build muscle if you get if you get enough protein you don't need to supplement with them and in some studies supplementing with them might actually interfere with the absorption of other amino acids that you need out of all those though leucine appears to be the key like if you're trying to synthesize muscle it appears that leucine is like the trigger that tells your body there's enough amino acids around to build muscle so you do want to make sure that there's plenty of leucine in your meals if you if you are trying to increase muscle protein synthesis let's see tryptophan is what we what your body uses to make melatonin so that's how people talk about you know turkey making you sleepy I think it's just a huge meal that we have for Thanksgiving that primarily does that so yeah so there's a few things there let's see here glutamine seems to be very important for the gut very important amino acid glycine glycine is one that often our diet is pretty low in because you know the average person that eats animal products they consume a lot of flesh right they consume steaks and ground beef and those kind of things those are really high in amino acids like methionine but our ancestors would have ate what's called nose to tail right they would have ate the entire animal and they would have they would have made bone broths and they would have consumed the connective tissue and organs and all that those types of foods are much higher in glycine so the average the average human today does not consume as much glycine as our ancestors would have and I think that that that occasionally can be a problem glycine's been shown to enhance sleep like I actually supplement personally with three grams of glycine a night as a as a sleep aid so but again not not medical advice but just kind of something interesting there and then see tyrosine there your body takes tyrosine and then the mineral iodine and that's what it that's what it uses to make thyroid hormones so so they all they all they all do very important things that's just a few examples to highlight there so 20 amino acids 11 or non essential not nine are essential meaning you must consume those so any complete this term complete any complete protein will have all nine essential amino acids in it and incomplete protein will be missing one or more of them that's what makes it an incomplete protein if you're if you're consuming a complete protein like the protein from egg whites for example then you have all you're meeting all your amino acid needs if you're completing an it or from quinoa or soy if you're consuming incomplete proteins like from from grains or legumes you have to you have to combine foods in a way to make sure you're getting all the amino acids so here's some examples of just how every amino acid looks exactly the same except for that side group and that's where the variation is so how are proteins built so amino acids are the building blocks of proteins they're just like the other two macronutrients they are built using condensation reactions you remove a water as you put as you as you form a peptide bond this red bond here the peptide bond that's that's joining two amino acids together and you build a long chain of those and oops I hit that sorry you build a long chain of amino acids and that's going to be these peptides and then that are polypeptides and then that's going to form your proteins so it'll be condensation reactions and just like the other two macronutrients hydrolysis reactions so do this in reverse is how you split them apart when you digest them so whenever you're looking at proteins these are going to be the four terms you hear as far as their structure you have primary structure secondary structure the tertiary structure and the quaternary structure so your primary structure is just the sequence I think we have better pictures here yeah the primary structure is just the sequence of amino acids so which amino acid comes next in the chain that's called the primary structure the secondary structure of a protein would be local changes in shape because you see like these bonds these these bonds forming here would cause local changes in shape so that's called the secondary structure of a protein the tertiary structure of a protein is the three-dimensional shape of the entire protein and the reason that's important is think about proteins kind of like keys right the shape of a key matters because the shape determines its function so the shape of all the proteins in your body is what determines what they do if they're not shaped correctly they won't function correctly and will have problems so that's called the tertiary structure and go back to the list there the quaternary structure is anytime you take more than one polypeptide chains and fuse them together to form a complete protein a good example that would be hemoglobin so hemoglobin is the the protein that allows red blood cells to carry oxygen well hemoglobin has four subunits that are fused together and that's what forms the quaternary structure of hemoglobin all right so primary secondary tertiary and quaternary structure this is an example of insulin the reason we use this one is it's so short it's only 51 amino acids some of your some of the proteins in your body are hundreds of amino acids long so this is definitely on the shorter end but this would be our insulin which we used to help control our blood sugar and you see that the the the primary structure would just be the sequence of amino acids then you see the local changes in shape that are caused by those cross bridges i think i've said all this the chain itself would be the primary structure if you see these terms dipeptide is two amino acids together tri is three and polypeptide would be 10 or more amino acids bonded together so the primary structure is the amino acid sequence secondary structure local changes in shape you'll see terms like pleated sheets and alpha helixes not a huge deal tertiary structure so the three-dimensional shape of that polypeptide chain and then if you put more than one of them together then you have a quaternary structure and that's the hemoglobin example i just shared so hemoglobin is a protein that's really designed to hold iron kind of like a wedding ring a wedding ring would would hold a diamond hemoglobin holds iron and or an iron is what gives hemoglobin its affinity for oxygen all right this other this next term very important the so we're talking about building proteins but denaturing proteins are how they're destroyed so if the three-dimensional shape of a protein matters so much if you if you unravel it and you destroy its three-dimensional shape you you change the protein forever and that's what denaturation is when you disrupt or destroy the shape of a protein so the textbook example is always an egg right you put an egg on a on a hot pan or a skillet and it'll be the egg white will be clear well when those proteins are denatured they become insoluble in water and they become the actual egg white um digestion would do this so the reason that we have hydrochloric acid the reason we have stomach acid is to one of the reasons is to denature proteins and unravel them so that we can digest them so the enzymes can actually digest the individual amino acids speaking of that digestion and absorption of proteins so in the mouth no chemical digestion occurs right just there's no enzymes that digest protein in the mouth just the mechanical breakdown of food occurs there in the stomach the stomach is where protein digestion begins uh the the enzyme involved in denaturing or the the stomach acid denatures the proteins the enzyme involved in actually chemically digesting the protein in your stomach is called pepsin but notice this term pepsinogen it's released from the stomach the cells of the stomach as pepsinogen which is a pro enzyme meaning it's an inactive enzyme that's one step away from being activated the acid in the stomach actually converts pepsinogen into pepsin and that's what gives it turns it on and gives it the power to digest proteins so protein digestion begins in the stomach but then we have a lot of other protein digestion enzymes a protein digesting enzymes called the proteases that are going to come from the pancreas and be dumped in the small intestine so that's where most protein digestion will occur but some does occur in the stomach all right what is the process when a protein uncoils or loses its shape that would be denaturation so we talked about that denaturation is the change in a protein shape and consequent loss of its function brought about by heat agitation acid bases alcohol heavy metals or other agents an example of denaturation is cooking an egg which I gave you or the curdling of milk so it's actually so think about like a baby like my son we used to call him a feta factory because he was lactose intolerant we didn't know yet so he would drink milk but he would throw up cheese right so basically the the proteins in that milk were being denatured in his stomach and then he was throwing them back up so feta factory was his nickname for quite a while until we realized that he was lactose intolerant we got that sorted out all right so protein digestion I've already told you in the mouth nothing chemicals happening just the mechanical breakdown of food in the in the stomach the pepsinogen is being activated and turned into pepsin so pepsin is is actually digesting the proteins hydrochloric acid is denaturing proteins and helping to break them down as you can see here hydrochloric acid denatures the proteins and activates the pepsinogen turning into pepsin and pepsin is starting to chop these long chains of amino acids into shorter and shorter chains then the food which is now called chyme moves into the small intestine and we have the proteases that come from the pancreas and then there's also some proteases that are just in the intestinal lining in what's called the brush border and they're going to take these the the remaining polypeptide chains and cleave them and chop them up into tripeptides 3, dipeptides 2 and individual amino acids and then the rest of that the rest of the enzymes are going to finish chopping them up but the end result is no matter how long of a protein is that you consume whether it's a 1500 amino acid collagen or a 100 amino acids doesn't matter the end result is we will diet we will continue to digest and digest and digest this protein these polypeptide chains until they are broken down into individual amino acids and that's what's going to be absorbed so you see here you got a lot of different enzymes involved i just called in the proteases as a group but you see that some examples here you'll notice that trypsin is one of the examples it breaks peptide bonds but specifically next to the amino acids lysine and arginine whereas chymotrypsin is going to break bonds next to phenylalanine tyrosine tryptophan methionine asparagine and histidine so that doesn't exactly matter but but you'll see that these enzymes are looking for they're just scissors and they're looking for where they can make their cuts and in the end all these enzymes work together to turn your proteins into individual amino acids you can read the rest of the list there all right now let's check number two proteins are susceptible to heat and acid an example of this process is in the body is during digestion when proteins are exposed to hydrochloric acid that's going to be in your stomach acid hydrochloric acid is present in the stomach hydrochloric acid uncoils or denatures each protein's tangled strands like i showed you that hemoglobin how coiled up it was it's going to unravel that so your digestive enzymes can actually digest the the bonds that are holding the individual amino acids together the hydrochloric acid also converts the inactive form of the enzyme pepsinogen to its active form pepsin already mentioned that all right now we're so we've digested our proteins down to individual amino acids now it's time to absorb them during absorption amino acids are transported by specific carriers to intestinal cells so they're going to be transported to and through the intestinal cells those cells are going to take the amino acids they need and the ones they don't need they'll continue on through into the blood stream and they'll work the way the liver where the liver will use it to build proteins and and deaminate amino acids to change them etc etc all right why do we need protein proteins in the body so here we see protein synthesis i won't go into all the great detail here but this is uh this is how our why we have genes and what they do you know we have our genetic code is a blueprint it's basically a a cookbook full of blueprints or something that and each of these genes is going to code for a functional product which is going to be it which is going to be a protein so so we have DNA then our body converts DNA into RNA which is the message that can leave the nucleus and go find a ribosome hopefully remember that from anatomy ribosomes are the site of protein synthesis where we actually will translate that message into a protein chain so proteins role in DNA the uniqueness of each person again my genes are different than yours which means that my proteins are different than yours and that's why i'm different than you diet so you know making sure we're getting enough protein well you can't do this and this is every protein synthesis has what's called a rate limiting amino acid right so and in any person at any given time whichever amino acid you have the least of is the rate limiter right there are 20 amino acids and you can have 19 of them let's say you don't have that loosing we talked about earlier you have a hundred times more more of all the other amino acids than you would need but you don't have any loosing what would happen protein synthesis would halt because anywhere you're building a protein where you would need the ends uh need the amino acid loosing it would just stop it couldn't build that protein so you have to get enough protein to build the proteins in your in your body but you have to make sure you have all of them or else this whole process would just break down all right so let's match these up the process of synthesizing messenger RNA so the process of converting DNA into RNA is called transcription the protein making factories so i already mentioned this the site of translation where proteins are built is called the ribosome another type of RNA that carries its amino acids to the messenger RNA that's the actual translator that reads RNA and brings amino acids with it that's called tRNA or transfer RNA and the overall process of making a protein is called gene expression so your genes are the code when your genes are expressed they actually make their functional product translation is the process occurring at the ribosome an error in the amino acid sequence alters the final protein the amino acid sequence determines the shape or structure and this shape determines its functions we've said all that and you'll see here an example this is sickle cell anemia so notice on the right we have a sickled red blood cell and on the left we have a normal shaped red blood cell which is called a biconcave disc so if someone has this condition then their genes are coding for a hemoglobin that has that has the wrong amino acid sequence so the the the the the code for hemoglobin is quote unquote wrong which means the shape of the protein is wrong which changes the shape of the red blood cell which changes its ability to carry oxygen so as the as the structure changes so does the function that's just one example all right gene expression and protein synthesis all cells all cells that have DNA can do this right we have our red blood cells don't have DNA anymore but that's why they have to be replaced by cells in the bone marrow but each type of cell makes only the protein that it needs which totally makes sense and that's why like I know we're rushing through this this isn't the section where I really want to talk about genetics too much that's covered more in anatomy and other classes but what my skin cells are different than my liver cell because of which genes have been turned off right all of my DNA is in every one of my cells but as cells choose the path and decide what they're going to become they turn off the genes they won't need so my skin cells are going to make proteins that my liver cells don't and my liver cells are going to make proteins that my skin cells don't that's what makes them different all right dietary influence on gene expression again this is something we're just beginning to understand but this idea of like epigenetics right we can influence our genes we can influence how they're expressed so we can't we can't change our genes we can't change our DNA I mean if we can I guess we can by mutating it with radiation and cigarettes and things like that but we can't actually change our genetic code but we can change how genes are expressed and this is this whole field of epigenetics which says that you know positive diet and lifestyle factors will cause your genes to be expressed in a better way than negative you know so if you're if you're smoking and you don't exercise and you're sleep deprived and you're stressed your genes are going to be expressed different than if you're sleeping well and happy and and not malnourished etc so we so we can impact our genes and we talked about that a little bit in earlier lectures about how like you know a high fat diet might might promote right might promote cancer and these types of things so yep a healthy per so this is where you see we all have our genes right but there here's a really a common phrase that says you know your genes load the gun the environment pulls the trigger right so you might have genes you might have a higher risk of heart disease than someone else because of your genes but it's not a guarantee you're going to get heart disease if you do the right things that trigger may never get pulled and so you so that means you have to be more diligent and more careful about your diet and your lifestyle factors than a typical person and just on the flip side so I mentioned in the last video the last lecture about how some people have familial hypercholesterolemia well their genes their genes mean that they're going to have high cholesterol and they're going to have to do things that you and I don't have to do to have the same risk of dying of heart of heart attack than you and I do but on the flip side there are people that have genes that that make their cholesterol really low and their lifetime risk of heart diseases is greatly diminished right they they their chances of getting heart disease even if they make a bunch of mistakes is still almost zero so your genes so genes do influence things but they they predispose us to certain diseases maybe so maybe cancer runs in your family or heart disease runs in your family or diabetes runs in your family but none of those things have to are guaranteed you just have to work harder to protect yourself from those things in with the lifestyle stuff with the environmental stuff all right so what do we use proteins for so I think most people think of proteins as structural materials we have you know your your muscles your tendons your ligaments the the connective tissue that holds your body together the protein portion of your bones right about about 30% of your bones is protein see you see there that this collagen matrix that once it's filled with minerals becomes bones or teeth if you ever want to see a really cool example of that take a a cleaned chicken bone or something and put it in vinegar that for a week let's say the vinegar will remove the minerals but the bone will still look the same but when you take it out of vinegar it'll be flexible and that's because the the collagen is still there the protein is still there but you've removed a bunch of the minerals so there is a protein component to things like bones proteins are needed to replace dead or damaged cells I mean every day you know countless cells have to be repaired or replaced in the human body and and we can break down old proteins and reuse them so it's pretty cool we need a lot more protein in a day than we eat and how we get away with that is whenever you're building a new protein in your body let's say seven of the of every eight amino acids that you're using to build a new protein we're old recycled ones and that one out of every eight has to be a new one that came from your diet so we are constantly breaking ourselves down and building ourselves back up and yes we do lose we do lose protein some things get broken beyond repair some things are just lost so when that happens that's why we have to eat protein right you can't just not eat protein and let your body just continue to recycle and repair itself you'll be in trouble there so we can we can reuse a lot of the amino acids in the human body but we do need a constant supply of new ones as well all right so those are kind of structural things then enzymes i've already mentioned these are catalysts that speed up the chemical reactions in our body so almost every reaction in your body is is sped up or powered by an enzyme and enzymes are made of proteins this is just showing how enzymes work hopefully understand that they the textbook definition would say that they lower the activation energy which which basically means that enzymes make each metabolic reaction in our body occur with less energy and it's going to occur much faster and much easier as well so enzymes are critically important like you couldn't build you couldn't even build a a theoretical living organism without at least hundreds of enzymes so they they are the reason we are alive um what else protein so you see that some of a lot of our proteins are our hormones are protein hormones uh you know in anatomy we talk about the the peptide hormones which you see a bunch of them here and then we do have some hormones that are made of individual amino acids so i won't go through the whole list but but the huge majority of your proteins are made of our peptides our amino acids are a huge majority of your hormones sorry the steroid hormones are made of fat or cholesterol but are made of cholesterol but most of your hormones are made of proteins so hormones are your endocrine system you can see some examples there and read those um proteins as regulators of fluid balance so you see here if someone has an imbalance if they don't have enough protein in their blood then their fluid basically fluid is constantly pumped out of your blood vessels and then sucked back in it's pumped out by hydrostatic pressure fluid pressure and sucked back in by osmosis but you need proteins to do that so if you don't have enough proteins in your blood because uh you're really malnourished or you have liver failure then the the fluid will be pumped out of your blood but it won't be sucked back in and you'll develop edema which you can see in this picture here so uh I always you know talk about like um basically there's two types of malnourished children you see really skinny children and then you see really skinny children that have a pot belly right but the belly is fluid it's not fat that kid is way worse off that means they have so little protein that their liver can't even generate the proteins like albumin that you need to regulate fluid balance so that's that's a serious problem um acid base so so proteins play a big role uh functioning primarily as buffers so they help to they help pH uh keep pH changes from occurring in the body so proteins are are part of maintaining your acid base or pH balance proteins are transporters on your cells and they're also transporters through the blood so here you see an example of a protein transporter in a cell membrane but there are also our proteins that carry lipid soluble hormones and things like that through our bloodstream sex hormone binding globulin would be one example speaking of the globulins right you have the immunoglobulins those are your antibodies i g g i g a i g m i g e and i g d so proteins are a huge part of your immune system as well just giving you lots of examples well that's the next one here so antibodies are made of proteins um they can be used for fuel remember we've said on several of the lectures so far a gluconeogenesis your body can turn non-carbohydrates into glucose and that's and it primarily uses proteins so proteins can be turned into fuel the downside of that is remember protein has nitrogen on it so if you're going to use protein as a fuel source you've got to deal with this excess nitrogen which we'll cover in just a moment um what else we talked about antibodies energy blood clotting so their uh blood the fibrinogen is is a is the protein that's turned into fibrin and that's how blood clots so that would be an example of proteins needed for blood clotting vision you need protein for everything really all right um okay a preview of protein metabolism so we're gonna we're gonna cover metabolism in a whole separate chapter but i mentioned the protein turnover right your body is constantly being broken down and repaired and renewed and that protein turnover so the huge majority of the amino acids you're going to use today or seven eighths of them anyways are going to come from recycled proteins and then you need to you need to constantly be topping off the tank so to speak this amino acid pool that's i mentioned earlier like i don't know where this pool is in your body i know we have this constant influx and efflux of proteins but we really we don't store them so we that's why you just need this supply whether it's coming from your diet or coming from the breakdown of old proteins doesn't really matter but you do need a constant supply of them because they're not stored protein breakdown so just that's the you know when you're repairing proteins and you're breaking down organelles you're just going to reuse the amino acids and then you top off the tank with dietary proteins all right so fill in the blank when nitrogen intake and output are equal a person is in what's called nitrogen balance or nitrogen equilibrium infants children and pregnant women are in a state of positive nitrogen balance and if protein is being lost and nitrogen excretion is greater than intake a person is in a state of negative nitrogen balance so if you're not growing or shrinking you should be in a state of nitrogen balance which means like you're consuming enough protein to maintain your body if you're growing so you see infants children pregnant women or if you're you know trying to add 10 or 20 pounds of muscle let's say you're an athlete or whatever you need to be in a state of positive nitrogen balance so there's um you have it you have more than enough proteins to build on the body you already have or build another body inside of you if you're pregnant on the flip side if you're if you're dieting or you're starving or you're protein malnourished you're going to be losing nitrogen every day so you're going to be breaking down more tissue then you can then you can maintain and rebuild this is why you know if someone loses 50 pounds really rapidly you you'd have to assume that depending on how it's done 15 20 25 or even slightly more than 25 of those pounds could be lean tissue because of this negative nitrogen balance situation all right um other other ways we use amino acids so I mentioned this first one already but you make things with it so I yes we have a bunch of hormones that are peptides but we also have hormones that are made of individual amino acids so you see here tyrosine is used to make epinephrine and norepinephrine which is adrenaline and noradrenaline tyrosine is also used to make thyroid hormone and then tryptophan can be used to make niacin and and the brain chemical or the body chemical i guess neurotransmitter serotonin and tryptophan can also be used to make melatonin so those will be some examples we've talked about energy if you're if you're out of carbs and fat as a fuel source your body can turn lean tissue into glucose similar to fat and carbohydrates protein is also easily stored in the body the answer is false so I guess we had this little puddle this amino acid puddle or pool but we there is no way to store amino acids you you use them uh or or you don't and that's why you need a constant supply of them next using amino acids to make proteins and non-essential amino acids so you see here that again you can swap some of these parts around to make new amino acids it's mean to me it's easier just to make sure you're getting all of them but your body can take um your body can build can basically turn one non-essential amino acid into another so if you need a whole bunch of an individual amino acid your body just kind of makes it as it needs it not a big deal but you see there this is called transamination so you're moving the amino group from one amino acid to another and that requires the vitamin b6 is the coenzyme that's needed to power this process deamination is different so if you're going to if you're going to remove the nitrogen group from an amino acid mainly to turn it into a fuel source then you've got a deal you get you take off the amino group and now we have to deal with this nitrogen and that's that's going to be what we do what we do with it here because we can't have all the samonia floating around in us which is NH3 so you take two ammonias and mix it with the carbon dioxide and you make urea and that's how we would get rid of the excess nitrogen that we don't need as because we because we used protein for something that didn't require the nitrogen so then we excrete it so you see here that the ammonia becomes urea and then our liver gets rid of the urea into the bloodstream and it goes to the kidneys and we get rid of it as one of our primary waste products in urine so you see here that urea the principal vehicle for excreting unused nitrogen is the urea that you'd find in your urine increases with protein intake which makes sense because if you're if you if you're eating more protein than you need as a at a base minimum then your body will have to do something with that protein turn it into glucose turn it into fat and if it's doing that it has to remove the nitrogen group and it does require right anytime you got to get rid of something in your urine there is what's called obligatory water loss so if you have if you're making more urea then you're going to make more urine and you're going to need more water so that's why if you go on a higher protein diet i do recommend you consume more water for that reason and that's why you see you know like your bodybuilders and athletes that are famous for eating a whole lot of protein they're also famous for drinking a gallon of water a day which is probably not a bad idea so discussion question why would a person on a high protein diet be at risk of dehydration when we just said it if they're um well let's just look at the answer but because if you've got to get rid of urea then you have to use water to to make the urine to get rid of urea so urea is the body's principal vehicle for excreting unused nitrogen and the amount of urea produced increases with protein intake to keep urea in solution the body needs water for this reason a person who regularly consumes a high protein diet must drink plenty of water to dilute and excrete urea from the body without extra water a person on a high protein diet risks dehydration because the body uses its water to rid itself of urea this explains some of the water loss that accompanies high protein diets so again um yeah if your if your if your water intake stays the same but your protein intake goes up you will be more dehydrated because you're going to lose more water as urine but you didn't make up for it by increasing your fluid gains proteins and food so where we find it so when you're looking at protein quality so if you call if you call a protein a high quality or low quality protein what does that mean so the first thing is digestibility which depends on factors such as the source and the food eaten with it so um so what proteins are digested the best whey protein is a famous example of being the really quickly digested protein whey protein egg white protein these kind of proteins they're generally you know they're they're digested really well then the other the next thing that determines protein quality is the amino acid composition you have to have all of the essential amino acids to be considered a complete protein so if you have um like trying to think uh let's actually have a bottle here so my so my collagen protein it's got it's got a lot of um it's got a lot of protein in it right a serving of this collagen protein would be 18 grams of protein but if you look at the you can't see it doesn't matter but if you look at the typical amino acid profile you will see there's zero milligrams of tryptophan so this is not a high quality protein because if I tried to live on that I wouldn't have any tryptophan in my diet so you have to have all of the key essential amino acids for a protein to be considered a high quality protein okay a reference protein the quality of protein determined by comparing amino acid composition with essential amino acid requirements so again it's just does it does it meet does it meet this basic standard of having all the essential amino acid you need and then a high quality protein has all the essential amino acids in large enough amounts not just some but enough that's that's required by humans like I mentioned earlier having some like let me see here this this has 524 milligrams of leucine that's that's not enough you're trying to build muscle collagen's not the way to do it like I use collagen protein occasionally for some different reasons like joint health and stuff but there's no tryptophan and there's not very much leucine this is not a high quality protein it is not one that a human would want to build muscle out of basically all right so what high quality protein I use that term complete protein there and then an incomplete protein would be missing something like that all right so here this is why these terms matter because if you are if you're gonna if your diet is based around incomplete proteins then you need what are called complementary food combinations so if you if you eat any animal product so meat dairy eggs they're all complete protein sources if you don't eat animal products because you're a vegan then um you can eat soy and quinoa because those are complete proteins as well but if you don't if you if you're so here's some example if you're if you're a vegan and your diet is based around legumes or beans and grains that's perfectly fine as long as you eat them together because legumes are going to be incomplete proteins grains are going to be incomplete proteins but they but when you take them together they cover the deficiencies of the other ones let me read this point in general legumes provide plenty of isoleucine and lysine but don't provide enough methionine and tryptophan so that's legumes beans but grains have the opposite strengths and weaknesses so grains have enough methionine and tryptophan but don't have enough isoleucine and lysine so if you eat only beans let's say red beans you eat only red beans you're in trouble you eat only rice you're in trouble you eat red beans and rice you're no longer in trouble so that's a complementary food combination a well thought out well planned vegan diet can absolutely be be healthy and can absolutely give you the proteins that you need um so like a peanut butter sandwich on whole grain bread red beans and rice right these the uh a salad with pine nuts or seeds added to it those are going to be examples of what are called complementary food combinations and so you get your complementary proteins neither of these would be good enough on their own they'd both be incomplete combine them and they now form a complete protein or a complete protein matrix whatever term you want to use okay protein quality is influenced by which two factors what is the difference between animal and plant protein quality why are some proteins considered to be high quality or complete all right protein quality is influenced by the protein's digestibility and it's amino acid composition so animal proteins are are the gold standard like a whey protein an egg white protein would be it would be like gold standard examples because they're more digestible you see here 90 to 90 percent digestible compared to plant proteins being 70 to 90 percent digestible and then animal proteins all have all the amino acids so that's why they would be considered the highest quality protein but i just showed you collagen proteins from animal products are not high quality because they don't have the all the essential amino acids you would need and they don't have the right amounts so can you build a healthy diet around plant proteins of course you can but since they're not digested as well uh like if you want to build you know if you want to use p protein soy protein those kind of things since they're not digested as well you should consume more protein to make up for the fact that they're not digested as well and then if you're consuming a bunch of incomplete proteins you have to make sure that you put them together in those complementary food combinations health effects and recommended intakes of protein so um just in the basics a sedentary so your protein intake is is really determined by your activity level so how many proteins are going to be broken down and need to be repaired so uh the a nice safe like the rda for protein for a sedentary adult is 0.8 grams per kilogram of body weight so your kilograms you take your weight in pounds and divide it by 2.2 that's how many kilograms you weigh take that times 0.8 that's the rda of protein if you're sedentary remember the rda is the floor that is the minimum you're supposed to consume not the maximum so the rda is the floor you're supposed to consume at least that much if you're a sedentary adult so let's make it an easy example if you're if you weigh 220 pounds then you'd be 100 kilograms and if you're a sedentary adult then you would take that 100 times 0.8 and you should be consuming 0.8 or you should be consuming 80 grams of protein a day that's the rda that's the floor so you you'll probably want more than that but then if you're um if you're an athlete that number climbs right if you're if you're a strength athlete you probably want to get closer to um 1.6 a 2.2 grams per kilogram which really boils down to right in the ballpark of one gram per pound of body weight so if you're a 220 pound powerlifter then you'd want to eat 220 grams of protein but again these are these are just kind of the basic guidelines so the and if you're if you're a vegan then you're going to want to eat more protein too because of that adjustability issue so let's say if you're a a vegan strength or a meat eating strength athlete you shoot for like 1.6 grams per kilogram if you're a vegan strength athlete maybe you'd shoot for 1.7 or 1.8 but it is size dependent right the the the the bigger you are the more protein you need but again if you're let's say you need to lose 100 pounds right maybe you should go maybe you should do your your goal weight might be might be a better idea right if you weigh 300 pounds and you want to weight want to weigh 200 pounds 220 pounds let's say you don't you don't need 300 grams of protein um maybe you'd use your goal weight that 220 would be how you determine your protein intake but you just got to play with these things all right so what happens if you don't get enough protein deficiency I mean we've already talked about it it halts protein synthesis and you'd have a really hard time protein energy malnutrition we talked about the examples where you'd have so little protein in your body that you're you're developing edema and things like that um it's a heart disease so animal protein intake has been linked to heart disease once your saturated not all saturated fat is bad but once your saturated fat intake reaches you know above 10 percent especially above 18 percent that's where you start to see problems so animal protein comes with saturated fat it's nothing the protein is great so if you if you don't want heart disease then eat leaner animal protein sources so less saturated fat more of the high quality protein um let's see I mean arginine is a is a vasodilator nothing super interesting there uh so cancer notice it says protein rich foods not the protein content of food so this is this means that you know a lot think about some of our foods that have a lot of protein are going to have a lot of sugar salt fat you know these kind of things it's not the protein in your food that that does anything when it comes to cancer it's just that the foods that have a lot of protein also have things that might increase your risk of cancer um so maybe there is some there is some link between protein intake and calcium losses so if you're eating a higher protein diet you may want to make sure you're getting plenty of calcium if you're getting a lot of your protein from dairy products that's probably being taken care of uh weight control so let's talk about this is where I wanted to talk about that protein leverage hypothesis a little bit more so studies have shown that people will eat subconsciously until their protein needs are met so they did these really cool feeding studies where they put people up a phase and let them eat until they were full full and the foods all looked really similar but the difference was with with different or the same groups and different groups and different studies but the percent of of calories that were on the tables that came from protein would change but people everyone in the groups or the typical person in each group ate until their protein needs were met which meant that if the percent of the calories in a meal from protein were lower they would eat more to reach that protein target so this and this could actually you can look into this but the protein leverage hypothesis I think it does a really good job of explaining the obesity epidemic right that um one of the things that happened is people like the demonized carbs and demonized fat but the real issue is as we started to eat more carbs and more fat the percent of our calories from protein went down so we started to over consume food to make up the difference and I so I do believe if you're trying to lose weight that you've got to get your protein first protein and fiber because they're satiating they'll keep you feeling full and then you then you kind of let the let the chips fall where they may so to speak as far as the rest of your diet but if you're trying to lose weight you shouldn't you should it's not medical advice but I'd recommend making sure you're getting plenty of protein because of its it's satiating effects and the fact that you eat less calories when you consume a higher protein diet kidney disease very important to note here it is possible that if you already have kidney disease that a high protein diet can cause problems not all studies show that but high protein diets do not cause kidney problems that's that's been a myth about protein consumption for forever that is just not the case all right so the guidelines what we I gave you some of those recommended you know guidelines like the 0.8 grams and things like that so where should we where do we get our protein I mean if you if you eat animal products then lean animal products and maybe low fat dairy products these these kind of things would be a good place to go you can get protein from fruits vegetables and grains but there you're not going to get a lot of them and you got to make sure you get right combinations so um yeah so that's so that's kind of where we're at with protein protein and amino acid supplementation so this um so if you're building muscle right obviously you need more protein so some people use protein powders and they have been shown to be helpful you don't need them if you can reach your protein targets without without protein shakes then then absolutely protein shakes are great way proteins a great way to get let's say you've reached the end of the day and you're like oh I'm 30 grams away from my protein target for the day and I'm trying to build muscle then have a protein shake but they're but they're not needed as far as like this this idea of the anabolic window like you've got plenty of time to get protein if you're getting your protein over three or four or five different feedings in a day and you're you're good it doesn't you know there is no magical window after you work out um you don't have to wake up in the middle of the night and drink protein these these kind of things it just doesn't seem to make a big difference whether someone consumes consumes protein three times a day or eight times a day doesn't really seem to impact um muscle gain at all so get your calories get your protein spread it out over at least three servings I recommend four or five but um that will work so if you're getting enough protein then supplementing with the individual amino acids doesn't appear to do much good I've already mentioned earlier that branch chain amino acids have kind of been debunked as a as a protein if you're going to supplement with something that isn't just a whey protein or a protein that has all the amino acids then maybe an essential amino acid supplement that has all of the essential amino acids would make more sense than just the branch chain amino acids but I just don't think it's needed just uh you know get get get protein from good healthy sources try to get as much as you can from whole food use protein shakes to fill in the gaps and you should be good okay uh what have we learned recognize the chemical structure of amino acids and proteins check summarize protein digestion and absorption check describe how the body makes proteins and uses them to perform various roles check explain the differences between high quality and low quality proteins or complete and incomplete proteins including notable food sources of each and identify the health benefits of and recommendations for protein I think we did it all right I hope this helps have a wonderful day be blessed