Biochemistry Notes/Practice Test

00:00:37 lesson on biochemistry and biomolecules alright so let's get started so when we look back to our science and knowing about chemistry and science 10 and science nine we we talked a lot about compounds and how compounds are are used within the body are with are used and made and so on how they react with each other so every single organism is made up on either organic or inorganic compounds so this is a newer concept unless you've taken physical science 20 so far to understand between the difference between a

00:01:15 organic compound and an inorganic compound okay organic compounds occur naturally in living things now it doesn't necessarily mean they have to be made by a living thing but they do occur natural living things and most of them are made by living things all organic compounds contain carbon this is a really key concept that all carbon containing or sorry all organic compounds contain carbon but not all carbon containing compounds are organic did i just lose you so some compounds that contain carbon are

00:01:58 not organic compounds and we'll talk about some of those examples as we get into inorganic compounds but all organic compounds contain carbon all organic compounds are very important to living systems so they are all required for living systems so these organic compounds include carbohydrates proteins fats and nucleic acids okay and we're going to talk about the the concepts and the how these compounds are what their importance are and so on as we move through this lesson most hydra most organic compounds

00:02:40 in in addition to carbon also contain hydrogen and oxygen okay they may also contain some other elements as well like nitrogen and sulfur and phosphorus but but for the most part organic molecules all contain carbon and most of them also contain oxygen and hydrogen so in living systems organic molecules are made of carbon well the backbone of most mole organic molecules are our chain of carbon molecules connected to each other now those bonds that hold together a carbon to another carbon store a lot of energy

00:03:23 so when a a molecule or a cell breaks apart that molecule a lot of energy is released so we'll look at molecules like carbohydrates for energy and that's why carbon is typically used in all organic molecules now carbon-carbon bonds are what are called covalent bonds remember back to science 10 we talked about covalent bonds and that is a sharing of of electrons between two non-metals now those covalent bonds not only do they hold energy but it takes a lot of energy to break them but when those bonds are broken it is far more

00:04:06 uh a better return for the energy so it takes a lot of energy to break it but the cell will get a lot of energy back in return when it breaks that bond now many organic substances are single molecules are what are called monomers and when you link many monomers together they form macromolecules called polymers and that's why organic molecules tend to get very large and complex so think of an organic molecule like lego you get one little tiny piece of lego that's a monomer to build your final structure you have to piece together

00:04:48 all kinds of little pieces of lego to make that final structure that final structure is the polymer so we use many small building blocks to make one large final product so monomers link together to make polymers and a lot of organic molecules are repeating monomers over and over and over again so that's next line there same thing many monomer subunits joined together form the molecules of life so if we see this diagram here on to the to your left you can see a series of monomers making polymers

00:05:30 so methane at the top here is a monomer it's a carbon with four hydrogens so it's an organic molecule so methane is the monomer and we know methane is a gas produced by living things usually find a lot in the gas of the digestive system now we take two methane and put them together and it makes a substance called ethane you take three of them put them together it makes propane well you all recognize propane from the stuff you put in tanks to power your barbecue and then you put four of them together

00:06:06 and it makes a compound called butane so this one monomer here makes many different polymers by linking them all together so that's what we mean when we say that monomers are the building blocks methane is that little piece of lego that gets linked together to make other products or polymers now an isomer is a little bit different than a polymer so an isomer is a compound with the same chemical formula but a different arrangement of those atoms within the compound so if you look at these three compounds here on this page we

00:06:52 have glucose we have fructose and we have galactose now the chemical formula for glucose is c six h i'm trying this to write this down here 12 0 6. that's an ugly six but that's the chemical formula for glucose so if we count them one two three four five six carbons 12 hydrogens there's one two three four five six 7 8 9 10 11 12 and six oxygens so there's one two three four five and six so c6 h12o6 that's our chemical formula for glucose now if you look at fructose count the number of carbons hydrogens

00:07:57 and oxygens on fructose it's exactly the same there are six carbons 12 hydrogens and six oxygens the exact same chemical formula but a different arrangement so you see up here at the top the top of this fructose looks different than the top of this glucose molecule where the rest of it from that point down is pretty close to the same and then same with this molecule here kind of right above my head okay that's galactose and it also has the chemical formula c6h12o6 so these three molecules are all isomers of each other

00:08:45 so pause the video now on this slide and fill out your notes so now we've introduced you to organic compounds let's introduce you to inorganic compounds because after this little introduction we're going to spend our entire time looking at organic molecules now if a compound is not an organic compound it is automatically an inorganic compound so inorganic compounds generally do not contain carbon so if it automatically if it doesn't have carbon in it it's an inorganic compound and so these are often what we will call

00:09:23 in your diet minerals or metals in your diet now there are some carbon containing compounds that are inorganic like carbon dioxide calcium carbonate and those types of compounds even though they're made by living systems like carbon dioxide we breathe it out as a byproduct of our body's metabolism using up the energy and part of our digestive system okay those are carbon-containing compounds that are not organic and they're generally very easy to recognize because they're very small very simple

00:09:56 okay and unlike methane for example with ch4 that's an organic compound whereas calcium carbonate carbon dioxide are inorganic ammonia which is produced by living systems nh3 is an inorganic compound because it doesn't contain carbon so the even though that our living system produces it by breaking down proteins it is still an inorganic compound so inorganic compounds even though they're not as complex as organic compounds a lot of them are very vital in the survival of living systems because a lot of them are vitamins

00:10:37 or enzymes in living systems so they are very still vital and important for living systems now probably the most important inorganic compound in living systems is water you know you can't survive without water okay a human can't survive more than three days without water so it's a really important inorganic compound it permeates all living systems now water is what we refer to as a universal solvent which means that it can dissolve just about anything given enough time it might take several days it might take several years

00:11:23 it might take hundreds or thousands of years but water can dissolve just about anything now water acts as a solvent in living systems so what that means is that a solvent is a substance that does the dissolving okay it usually is in larger amount when substances are dissolved so if you if for example you have a glass of water and you have some sugar you pour the sugar into the water and stir it up and the sugar disappears right the water has dissolved that sugar into it so the sugar is still there

00:12:11 it's just in a different state okay it's being suspended still in a in a small solid form because we can get the sugar back out of it by evaporating the water the solute is the substance that is dissolved so my previous example of the water and the sugar the water is the solvent the sugar is the solute so living systems need this relationship because in order for nutrients to be transported and get into cells and transport around the body they have to be dissolved in water so that sugar for example

00:12:49 has to be dissolved in water to get into the cell a solid grain of sugar can't get through the cell membrane of a cell it has to be dissolved in water so living cells would not be able to carry any nutrients into their tissues and stuff if they were not dissolved in water so water is essential for the survivability of living systems now pause the video here and complete your notes on inorganic compounds all right so let's get back to organic compounds that's the important part of this whole thing on biomolecules is looking

00:13:29 at organic compounds different kinds of organic compounds okay we've already said that organic compounds are essential to life and organic compounds are often very recognizable because they tend to get a lot larger than inorganic compounds they like carbon dioxide very small compound it's only three atoms whereas things like glucose and lipids and the other organic compounds gender get really large because we can take many monomers and piece them together to become those big polymers so what are organic compounds in the

00:14:03 groups of organic compounds well carbohydrates okay carbohydrates are what we typically call sugars and starches okay there are lipids which are fats oils and waxes there are proteins which are made up of amino acids so things like meat and muscles and those sort of things are made are protein made up of proteins and nucleic acids so this is the genetic material of the cell so they come in basically two varieties there's rna and dna and there are different kinds of rna and these are the ones that carry the

00:14:37 genetic information for a cell so pause the video here and write this down complete your notes so the first type of organic molecules we're going to talk about are carbohydrates now carbohydrates are short-term energy storage okay sugars for example okay like glucose like sucrose fructose galactose all those different carbohydrates so in the short term an organism will use sugars or straight carbohydrates now if you have enough carbohydrates in your bloodstream or in the organism the organism will put it into an

00:15:26 intermediate term storage molecule and that's starch for plants or glycogen for animals it's still a carbohydrate okay but it's a storage form of the carbohydrate now if it turns into long-term storage then that energy gets converted into long-term storage molecules which we typically refer to as fats so some carbohydrates along with energy also forms structural components within organisms so cellulose in the cell walls of plants is a carbohydrate chitin which is another carbohydrate that has found the

00:16:06 exoskeleton of insects and other arthropods what gives a beetle it's crunch when you step on it that is a carbohydrate as well now pause the video here and complete filling in your notes on carbohydrates now the next type of organic mole you're going to look at are lipids now we often refer to lipids as fats but fats are just one type of lipid there's lots of other types of lipids out there and a lot of people will interchange the two words as fats and lipids okay lipids are more than just fats okay now lipids in most organisms

00:16:51 are primarily long-term energy storage molecules that are not soluble in water so they typically like the old saying goes oil and water don't mix well they don't look at a bottle of italian salad dressing and you can see that oil and water don't mix the water sits on top or the oil sits on top and the water and the spices float to the bottom and you have to shake it up to mix them up to pour it on your salad and then shortly after they separate out again okay so lipids for most part in most organisms

00:17:23 is long-term energy storage right you've seen me right i've got lots of long-term energy storage okay now lipids store a lot more energy than the equivalent amount of carbohydrates so if you had a kilogram of fat and a kilogram of sugar and you burned them you get a lot more energy from that kilogram of lipids than you would that kilogram of sugar of carbohydrates and that's why your body stores excess energy as fat as lipids so that it's more it's a higher more dense form of energy storage so the the plants will also

00:18:13 store those sugars as or that excess energy as oils so plants store those excess energy and excess sugars as starch and then if it builds up more enough starch it'll start to produce oils so just think about some of the products that you use at home corn oil peanut oil canola oil sunflower oil all those different oils are lipids produced by plants now fats in law in addition to long-term energy storage also can act as insulators and cushioning agents so as a cushioning agent you naturally store fat into high

00:19:00 impact areas of your body like the palms of your hands all these little little pads on your hands okay are all lined with fat or your elbows or your buttocks okay ladies on your hips because your pelvis is turned since your pelvis is turned outwards okay your ends of your femurs and your hips are exposed so your body naturally puts fat on the outside of it to protect it okay and the bottoms your feet are another place so in high impact areas your body naturally puts fats okay like i said your buttocks in

00:19:40 other areas as well as your insulating capacity if you think of a lot of animals like arctic animals like whales and polar bears they and seals and walrus they have blubber blubber is fat and they put on that fat to keep warm so people who have more fat like myself for example i have a fairly healthy layer of insulation i'll stay warmer than some skinny little supermodel right because i have more insulation to keep myself warm now lipids are composed have a structure a little bit different than

00:20:20 other organic molecules okay they're composed of their monomer is a [Music] is a chain of three fatty acid molecules bound to one glycerol molecule and a glycerol is a derivative of a carbohydrate so we have that glycerol molecule with three fatty acid chains hanging off of it so here's a picture here we can see of this is a lipid molecule okay there's our glycerol molecule at the top and there's our one two three fatty acid chains that are often that's the monomer of a lipid and then these these molecules get

00:21:05 linked together to form the larger lipids and we see that fats do not are not soluble water lipids are not soluble in water so this picture on the right here is fat droplets inside the adipose tissue so just underneath your skin between your skin and your muscles so that would be where your fat collects and it collects in droplets because it's not soluble in water this is another picture of what a what a lipid would look like so you see here's the glycerol molecule and it looks like half of a glucose molecule

00:21:42 and then you have your three fatty acid chains coming off of that one glycerol molecule now when we talk a lot about lipids and fats you've probably heard the terms saturated and unsaturated fats but do you really know what it means what's the difference between a saturated fat and an unsaturated fat now i'm sure you've seen those types of terms on food packaging before okay a lot of potato chip manufacturers advertise zero trans fat on their packaging so what what does that mean does that mean it's healthier does that

00:22:33 mean it's unhealthy what does what are trans fats is that to mean that all fat is bad for you what do you think well let's go get the skinny on fat no you can't get away from mills as bad jokes in a video presentation ah so pause the video here fill in the blanks in your notes and then restart the video and can let's continue so what is the difference between a saturated fat and an unsaturated fat well here's the basics of it a fatty acid that does not contain any carbon-carbon double bonds is a saturated fatty acid

00:23:32 if the chain of carbons in that fatty acid has double bonds in it it's an unsaturated fatty acid well mills so what a difference between a double bond and a single bond in a molecule makes a huge difference well let's figure out and show you why now saturated fatty acids saturated fats pardon me are generally solid at room temperature so like butter okay you leave butter sitting on the counter it stays a solid saturated fats generally come from animal sources so think of like the fat on the outside

00:24:17 of a steak or a pork chop that stays stays solid at room temperature and then when you heat it up then it melts away okay so that's two characteristics of a other characteristics of a saturated fat now consumption of saturated fats is linked to heart disease so having an overabundance of saturated fat is often a bigger concern than your cholesterol and cholesterol we'll talk about that a little bit later as well but that comes a lot from animal sources as well now unsaturated fats typically aren't

00:24:53 liquid at room temperature so you think of some lipids that are liquid at room temperature well they often come from plant sources like canola oil or olive oil okay those are generally filled with unsaturated fats so we look at this this slide here it's showing you the difference in the structure of a saturated fat and unsaturated fat so this saturated fat you can see in this long chain of this lipid there are no carbon-carbon double bonds they're all singles we're in an unsaturated fat which has the same ending on it here and

00:25:36 here we look here there's a double bond in that fatty acid chain now the way it's drawn there is not a mistake there is a slight bend or a kink in that fatty acid so you see it bends and these hydrogens are both on the same side which creates that kink this allows enzymes easy access in to break down this fatty acid so actually that's why unsaturated fats are more healthy for you because your digestive system can more easily break them down and turn them into useful components for your body systems

00:26:24 now unsaturated fats we know are healthier for us they're generally liquid at room temperature well in the course of food production those unsaturated fats you know want to incorporate them into products with them in their liquid form can be a problem so typically unsaturated fats when used in commercial operations can be hydrogenated now what hydrogenation means is that they bombard those unsaturated fats with hydrogen molecules which kind of changes them into temporary saturated fats now they're not completely saturated

00:27:05 they still have the double bonds in them by bombarding the hydrogen they take on more characteristics of a saturated fat and stay solid at room temperature like margarine for example when you leave margarine on the counter it's generally solid right it's soft you can spread it but if it gets on a hot day outside or you leave it on the counter it can start to melt okay so that's a hydrogenated unsaturated fat now hydrogenation of oils makes your french fries taste good but there's a problem is that if those on those hydrogenated

00:27:44 unsaturated fats are constantly reused like in deep fryers okay what can happen is is the bonds on that on that unsaturated fat can change and if those bonds change it's what's called a trans fat so i'll show you the difference in a minute the bonds i showed you in the earlier on the unsatisfied you saw that kink in it right that little bend in it there that because the two hydrogens were on one side that's what's called a cis bond of an unsaturated fat but if that bond changes and the arrangement of those hydrogens

00:28:26 changes it forms a transbond and trans fats with trans bonds are carcinogenic which means they can cause cancer so we look at this diagram here you can see on the bottom here is a typical cis bond in a normal unsaturated fat it creates that kink the two hydrogens are on the same side of the chain whereas if you look at the trans fat at the top that extra heating and using it completely has caused the hydrogen from up here on top to switch over to the other side and it takes that kink out of the fatty acid chain and

00:29:10 prevents enzymes from breaking it down properly so therefore it builds up in your in your body and can cause cancer so that's it that's the difference between a a regular healthy unsaturated fat and an unhealthy trans fat so it's a good thing that that companies have changed their practices to help reduce and eliminate trans fats in their product so now when you see that label on a on a packaging say no trans fat you know why it's important to not have those substances in that product so now pause the video here and complete

00:29:54 your notes on saturated and unsaturated and trans fats once you're done start the video up again and we will continue now one of the huge things in diets today and everybody's panicking about the amount of fat in your diet you know there's all these diet fads and stuff and that's we've addressed this before but believe it or not fat is actually good for you and approximately 30 percent of your daily energy intake should be fat the problem is we're not gained a lot of people aren't gaining weight and we and like

00:30:29 the united states one of the fattest nations in the world and canada we've got our fair share of of overweight people as well it's not the amount of what we're eating or it's not the amount of fat or diet it's actually how much we're eating north americans eat like there's a shortage of food in the world right and if you actually look at at historically the size of dinner plates have increased by over 20 percent over the last 30 years if you're to look at some of your grandparents dinner plates

00:31:00 you'll notice that they look small well and you look at the dinner plates we have now they're a lot bigger so just by having bigger plates we tend to take more food and eat more food okay so it's more important to be careful about the amount of calories that you're in taking and that you're utilizing and burning than worrying about what's in that how much you're taking in fat and carbohydrates and so on so no matter how much you eat or what you eat if you're in taking more calories than what you're burning you

00:31:35 are going to gain weight so now let's talk about another couple elephants in the room when you look at lipids and that's cholesterol and steroids hey whenever you hear these two words often people think oh they're bad cholesterol oh steroids bad but you know what they are important in living systems you can't cut all the cholesterol out of your diet okay you need it in your diet okay and steroids are a normal part of cell function cholesterol is important because it strengthens the fluid-like cell membrane and stiffing it

00:32:18 for support and just like anything else the problems occur when you have too much of it okay excess cholesterol can stiffen the cell membrane too much leading to health problems like arthrosclerosis the hardening of the arteries okay we we visited that really shortly at the end when we talked about our terminology and stuff like that right the build up of cholesterol plaque inside the arteries which can cause a heart attack human steroids are naturally occurring part in your body estrogen and testosterone are sexual

00:32:54 hormones in your body they are steroid hormones again the problem occurs when you have too much of those in your body so we look at this diagram these are three normal hormones in the body okay progesterone which is the female hormone of pregnancy testosterone the male hormone sex hormone and estradiol which is estrogen and we see they're all very similar to each other in their structure and function and when somebody is in taking steroids okay so using anabolic steroids to build muscle and they often create have many

00:33:36 different side effects to it that's because when they have excess testosterone in their system the body's what it does is it takes some of that excess testosterone and will convert it into estrogen and that's what creates some of the side effects of steroid abuse so if we look at this who yeah way too many steroids i know this is a doctored picture but i'm using it to make a point right who thinks that would be attractive and all those great big hulking muscles okay that a lot of bodybuilders have

00:34:14 there are a lot of potential negative side effects and we'll see some of those side effects and what you'll see a video later on we did deal with the muscles unit about steroids okay and i want to address it because it's actually a huge problem with teenage boys in that they start taking steroids because they they think they need to have that perfect body that muscular body to attract the girls right and so they resort to steroids to speed up that process okay now negative side effects are aplenty

00:34:47 for both males and females for steroid use okay so for example baldness oh yeah that's my problem [Music] okay but yeah excess steroid use will cause your hair to fall out that's what excess testosterone in the body do it does so i'll say i got extra testosterone my body i'm a manly man right okay it can cause a myriad of different health reasons so you see some the white ones are problems in men and women strokes and blood clots high blood pressure and heart disease okay that's just because of the extra

00:35:21 stress that your body's put through and the extra stress your heart is to keep up with the demands of the muscles that are trying to grow very fast okay nausea bloating impotence so impotence the the um inability to uh to perform sexually okay yes there are little blue pills for that but that's not gonna help a lot of people who are abusing steroids a reduced sperm count and that's because of a shrinkage of the testicles you're overloading your body with testosterone so your body's re resorts to well i

00:35:56 guess we don't really need the testicles to produce it because there's lots here so they so the testos begin to shrink okay which reduces sperm count you get aching joints because of the excess stress when the big growing muscles grow faster than that than the tendons that are holding the muscles to the joints so it's creating excess stress across those joints because the excess tension on your tendons which can cause also increased risk of tendon injuries it also causes aggressive behavior we've

00:36:28 all heard of roid rage right well that's a generally you have excess testosterone testosterone is what makes males aggressive so it creates excess problems there an enlarged prostate gland urinary and bowel problems mood swings a real huge chance for depression okay liver damage from trying to to your body's trying to get rid of all the extra things that are are created by the excess steroid use in your body severe acne on the face and back development of breasts in men yes you can develop breasts and

00:37:06 small adipose tissue under the nipples because you're getting that testosterone being converted into estrogen and then women get reduced breast size an enlarged clitoris okay a increase in facial and body hair a deep in the voice so they get the men get some female characteristics and the women start to develop more male characteristics because of the testosterone and in the men the excess a little bit of estrogen so there's a lot of major negative side effects between steroid abuse now using it

00:37:38 under a doctor supervision for re recovering from an accident or something like that is a completely different story we're talking those people that abuse steroids so pause the video here complete your notes on cholesterol and steroids and then let's continue now the the next type of of organic molecules we'll look at are nucleic acids now there are two different types of nucleic acids there's rna and dna now rna is a single stranded nucleic acid that plays a role in coding information for building of proteins within the cell

00:38:24 dna is double stranded so rna has one strand dna has two strands okay and it's the one and the dna is what carries the blueprint or the information to make another complete one of you so the dna is what carry what what carries your genes so it carries that code that instruction manual that blueprint to build another one of that organism so the dna in your body you have 23 paired chapters there are 23 pairs of chromosomes in your body so you have 46 chromosomes in total you get 23 from your father and 23

00:39:11 from your mother so at conception when you're conceived so when sperm meets egg and they combine you get your full 46 chromosomes now genes on the chromosomes are sequences on that dna excuse me dna strand they are the codes for specific functions specific structures or traits like brown eyes blue eyes brown hair blonde hair okay those are all contained on the genes that are on your chromosomes now the dna has two complementary strands okay which means they're mirror images from each other so think of your hands

00:39:54 right your hands are exact mirror image opposites so are the strands of dna they're exact opposites they're actually run in opposite directions and we'll learn more about that when we get in biology 30. okay now the bonds that hold those strands together are hydrogen bonds they're not overly strong bonds but enough to hold it together so if you think of the in the dna strand like a zipper right it's held together it could be unzipped and it can be zipped back up again which is important for the

00:40:26 copying of that and we talked a little bit about that in mitosis when we are in grade nine now the monomers of nucleic acids are what are called nucleotides so your dna and rna strands are long repeating monomer subunits okay so the whole dna polymer is made up of many many nucleotides all connected together so the main function that long sequence is information storage that's what a dna does it stores information and rna the information on that single rna strand is used to make proteins now the nucleotides are made up of three

00:41:13 components a sugar a nitrogenous base and a phosphate group and those three things make up the nucleotide and we'll see some structure of that in a minute now the sugars come in two flavors depending on what type of nucle which type of nucleic acid it is if it's dna deoxyribose so deoxyribonucleic acid and if it's rna it has ribose so ribonucleic acid so this is a picture of or a drawing of a nucleotide we have our five carbon sugar connected to that is a phosphate group and then your nitrogenous base and your

00:42:00 nitrogenous base also comes in four flavors depending on the nucleotide and that's what makes up the dna strand so we take all those nucleotides and we connect them together to make one side of the dna strand and then we take those strands and they go in the opposite direction because notice in that they're both running in opposite directions these two look at the red sugars on this on the right side here they're pointing downward and on the left side it's pointing upward they're running in opposite

00:42:34 directions okay and we piece all those monomers together to make the dna polymer so we see there's one nucleotide there there's another nucleotide there there's another nucleotide there and it get pairs up by another nucleotide on the other side and it's held together by these hydrogen bonds in the middle and that's what holds that whole dna strand together so you can see the repeating monomer subunits to make the the the whole polymer the dna polymer so now pause the video here complete your notes

00:43:16 and then restart the video and we'll continue now the last organic molecule we need to talk about are proteins now proteins we often refer to them as polypeptides because they're made up of many peptide bonds they are extremely important in living systems because they control a lot of the bodily functions things like enzymes and hormones or there are a lot of structural elements so things like muscles ligaments tendons they're all made up of proteins now enzymes and hormones are two of the most common proteins

00:44:02 in the human body enzymes are important because they act as catalysts so which means they control chemical reactions so they can either be used to break apart bigger they'll break apart the polymers into their monomers or they can be used to put them together so all chemical reactions in a living organism are catalyzed by enzymes now proteins they are compounds that are made up of carbon hydrogen oxygen just like carbohydrates but they also always contain nitrogen and that's the amino group of an

00:44:44 amino acid so carbon hydrogen oxygen along with nitrogen so pro proteins always always always contain nitrogen now some of those amino acids and proteins can also contain sulfur and phosphorus depending on what amino acid is making up that protein now like i said the building blocks of proteins are amino acids so amino acids are the monomers of proteins now proteins are just basically long chains of amino acids linked together by what are called peptide bonds and that's why they're called polypeptides they're many peptide bonds

00:45:29 so those long chains amino acids then are converted by the body and turned and folded to make the globular protein structure now there's only about 20 different amino acids in the world actually there are only 20 amino acids in nature and it is the combinations of those proteins put together that make the protein so it's the types of amino acids and in the combinations and then the length of that that amino acid chain that determines the proteins whether it's a really big protein or whether it's a really small

00:46:06 protein so a little pet peeve from a science teacher we often have heard and seen protein shakes well something that that bugs you know protein shakes on oh yeah i'm drinking protein no you're not it's actually protein shakes are actually amino acids you're not drinking protein you're drinking amino acids so when you have that protein shake you have it's a concoction of all 20 of these amino acids and you can see them here in that chart below and no you're not going to have to memorize these amino

00:46:52 acids okay so really when you're drinking a protein shake you're technically drinking an amino acid shake but i know amino acid shake is a marketing ploy doesn't sound very appetizing so that's why they call it a protein shake so don't get the misnomer okay you now know the truth about a protein shake so pause the video here complete your notes on proteins and then restart the video and we'll continue so let's wrap up our talk here of organic molecules looking at some very important proteins in the body

00:47:34 enzymes okay like i said earlier enzymes are necessary for most of the chemical reactions that take place in a cell they're catalysts right they control the reactions in the cell and they allow for us to to harness the energy that are tied up in a lot of those organic molecules and utilize them for useful purposes for a living cell and for your body okay the burning of glucose is controlled by enzymes your body's metabolism okay when you eat that sugar how your body breaks that sugar down and into usable energy for your body is

00:48:15 all done by enzymes which is really important because there's a lot energy tied up there and if we just allowed all that energy to escape all at once it could actually damage the cells of your body right enzymes act upon what's called a substrate so the substance that an enzyme works on to break down or to build is called a substrate the substrate can be a foreign protein like an antigen in your body some kind of foreign invader or it could be a nutrient in digestion that needs to be broken down to be useful in the cell so

00:48:53 substrates can really vary now the key thing there is on the enzyme can recognize that substrate the enzyme has what's called an active site on it which is very very very specific enzymes are specific to only one kind of substrate so one enzyme or works only on one chemical compound and that's it now we can recognize enzymes in scientific literature and in your notes and so on as we get through into nutrition because most enzymes end in the suffix a s e so if you hear the see the suffix ase it generally means

00:49:40 it's an enzyme so for example sucrase is an enzyme that breaks down sucrose lipase is an enzyme that breaks down lipids lactase is an enzyme that breaks down lactose the milk and sugar or the sugars in milk okay so you can often recognize what the ends what an enzyme is and also what it breaks down now that's not always the rule there are other enzymes that don't follow this rule but in general terms if it ends in ase it is an enzyme now enzymes have very very specific conditions that allow them to work

00:50:20 effectively your body has what or maintains what we call homeostasis a constant internal body environment so the ph stays the same the temperature stays relatively the same it's all very very consistent okay the ph and temperature play a huge role in the effect of a semin enzyme if that ph or temperature changes it can affect how well that enzyme can function so if the temperature and and ph are not optimal the enzyme will denature which means it will break down or change its shape which means that the active site won't

00:51:02 work anymore and the enzyme won't work anymore now we know that enzymes are proteins so let's relate to something maybe you're more familiar with let's look at ph acidity right if i were to take a glass of milk okay we know is has a lot of protein in it an hour to pour that milk into a glass of lemon juice we know a lemon juice is really acidic what happens to that milk when it pours into that glass of lemon juice well if you said it gets lumpy and it curdles you're right now why it curdles and changes all

00:51:45 lumpy is because the proteins in that milk aren't are don't handle acidity very well so those proteins denature they change their shape and get clumpy okay that's the same that happens when milk sours right the bacteria in that milk produces lactic acid which causes the milk to curdle we use that to make things like cheese and stuff like that now for temperature let's look at an egg crack an egg in a bowl in your imagination and look at that egg okay you have the egg yolk and the the albumin the egg white or on the outside

00:52:28 is kind of a clear yellowy kind of looking material the albumin has lots of protein in it now we dump that egg into a hot frying pan what happens well that egg white is no longer clear it turns pure white and that's because the proteins in that albumin denature due to the heat they change their form so they're not no longer a liquid they turn into a solid and turn into a bit of a different protein so if an enzyme happens to that it changes its shape it'll no longer be able to act on the substrate that it's meant for

00:53:06 and that's why your body works really hard at maintaining a stable internal environment homeostasis so pause the video here and complete your notes on enzymes and then restart the video and we'll wrap this up so that's it that's biomolecules and biochemistry you now have a foundation to understand what we're going to continue to work on throughout this course when we look at nutrition digestion cardiovascular system respiratory system and all this other stuff that has to deal with regulation of body systems okay

00:53:53 so go back and review these as you need to and from now continue on and start working on your assignments for this biochemistry unit either the handouts you've been given in class or things assigned through the google classroom good luck see you soon