so this video is for those of you who need to review the macro molecules their structure function subunits and things like that so for each of these questions feel free to pause the video and try it yourself once you have the answer play the video to see if it's correct so let's start with this one number one name the four types of macromolecules so the first one are carbohydrates these macromolecules have the empirical formula ch2o the second type are lipids these include your triglycerides your fatty acids your steroids phospholipids and things like that the third type are the proteins and the fourth type of macromolecules they need to be aware of are nucleic acids so those are the four main biological molecules that you need to know for the test you're studying for number two which of the following carbohydrates is a monosaccharide a monosaccharide is basically a monomer of a carbohydrate it's the smallest subunit of a carbohydrate and glucose is a monosaccharide here is the structure of glucose glucose is a six carbon sugar and it forms a six membered ring so this is carbon one two three four five and six and the other atoms are hydrogen atoms glucose is an aldo hexose whenever you hear the end in ose it tells you it's a carbohydrate now when you think of hex hex means six so we're dealing with six carbon sugar and the aldo part tells us that it has an aldehyde functional group in its straight chain structure so glucose can convert into this structure this is the straight chain structure and you could see the aldehyde functional group here so that is the linear structure of glucose now let's move on to answer choice b fructose fructose and glucose are similar in some ways they're isomers of each other both glucose and fructose they have the same chemical formula c6h12o6 they both have six carbon atoms 12 hydrogen atoms and six oxygen atoms but the structure of fructose is different than glucose fructose forms a five-membered ring it still has six carbon atoms though so this is the structure of fructose so this is carbon 1 2 3 4 5 and 6. now fructose is a ketone hexose it's still a hexose because it has six carbon atoms but it's a linear structure has a ketone functional group as opposed to an aldehyde functional group so i'm going to draw that real quick so that is the linear structure of fructose and here is the ketone functional group and that's how it differs from glucose so fructose is a constitutional isomer of glucose they have the same chemical formula but as you can see the atoms are connected differently we have two different functional groups here now this is called d fructose and the reason for that is because the o h group here is on the right if we were to switch these two groups and then it would be l fructose if the o h was on the left side now let's move on to galactose both glucose and fructose are monosaccharides of carbohydrates galactose would you say this is a monosaccharide that is it contains only one sugar unit a disaccharide two sugar units or a polysaccharide where it has many sugar units galactose is a monosaccharide like glucose it's made up of one sugar unit i'm going to draw the straight chain structure of galactose and notice how it differs from glucose this is once again d galactose since the o h group here is on the right but notice that this hydroxyl group is different from this one so this is carbon one two three four five six so glucose and galactose they differ at carbon 4. everything else is the same they have the same functional group they're connected the same way but they differ in the way the elements are in range in space so these two monosaccharides glucose and galactose they're known as stereoisomers they're connected the same way they have the same chemical formula but their atoms are arranged in space differently now galactose is specifically called a c4 epimer because it's only different on the fourth carbon so it's a c4 epner so we can eliminate answer choice c because that's another monosaccharide so do you think the answer is d or e sucrose or viable so what would you say now ribose is a five carbon sugar it looks like this ribose is an aldo pentose like glucose it forms an aldehyde functional group in its straight chain form but it's a pencils because it has five carbons as opposed to six so penta means five six means hexa anytime you see oats you're dealing with a sugar now ribose is one it's a one sugar unit so it's a monosaccharide the answer is sucrose sucrose is composed of two sugar units it's composed of glucose and fructose so because sucrose has two sugar units it's not a monosaccharide but it's a disaccharide mono means one die means two so sucrose is the answer number three which of the following polysaccharides is the structural building material of insects would you say it's starch glycogen chitin cellulose or maltose well let's talk about it so we said that monosaccharides contain one sugar unit a disaccharide contains two sugar units a polysaccharide has many sugar units and the number of sugar units could be in the thousands so that's a polysaccharide starch is a type of polysaccharide it consists of glucose monomers starch is a polysaccharide found in plants and it's used to store energy a good example of starch would be potatoes now starch consists of two types of polysaccharides you have amylose and amylopectin now what you need to know about these two is that amylose tends to be straight amylopectin has branches but they both consist of the glucose monomer so a is not the answer we're looking for it's a polysaccharide but it's not the structural building material of insects glycogen is similar to starch but glycogen is found in animals it's used to store energy as well and glycogen is highly branched so this is not the answer either chitin is the answer chitin is the polysaccharide material it's the polysaccharide that is the structural building material of insects so c is the correct answer d cellulose is a polysaccharide that is found in plants but this particular polysaccharide has a structural function it's found in the cell walls of plants maltose is not a polysaccharide maltose is a disaccharide so maltose consists of two glucose units connected to each other sucrose as we mentioned before is glucose and fructose another one lactose this is a disaccharide consistent of glucose and galactose so those are the three disaccharides you need to be familiar with but chitin is the polysaccharide that is the structural building material of insects so that's it for this question number four which of the following are monomers of proteins would you say it's monosaccharides nucleotides fatty acids amino acids or nucleic acids well we know it's not monosaccharides monosaccharides are the monomers or subunits of carbohydrates it's not nucleotides nucleotides are the monomers of nucleic acids and nucleic acids those are macromolecules fatty acids fatty acids can join to form a triglyceride a triglyceride contains three fatty acids and a glycerol molecule so this is not really a monomer of proteins the answer is d amino acids when you have many amino acids joined together they will form a polypeptide and as the polypeptide chain folds you have a protein so proteins are made up of amino acids so d is the correct answer for this problem number five which of the following structures represents an amino acid well let's go through each one let's start with answer choice a so what is represented by answer choice a this is a fatty acid which is a type of lipid fatty acids they contain a carboxyl group and a nonpolar hydrophobic tail that cell consists of hydrocarbons and hydrocarbons are nonpolar they're hydrophobic they don't mix well with water the carboxylic acid functional group that's a polar functional group and that part mixes with water that's the hydrophilic part of the fatty acid so answer choice a is not what we're looking for answers excuse me answer choice c represents a triglyceride triglycerides also fall under the category of lipids a triglyceride contains three fatty acids here's the first one second and the third one and it's attached to a glycerol molecule now this particular fatty acid is a saturated fatty acid the reason why it's a saturated fatty acid is because there are no double bonds this is an unsaturated fatty acid because there is a double bond now if you have a fatty acid with multiple double bonds then you have a polyunsaturated fatty acid so that's the difference between a saturated fatty acid and an unsaturated fatty acid it's whether or not if they have double bonds anti-choice d is a steroid molecule anytime you see four fused rings together that tells you it's a steroid which falls under the category of lipids these molecules are also non-polar they don't mix well with water whenever you have a hydrocarbon whenever you have a molecule that consists of carbon and hydrogen it's going to be nonpolar so all of this is the non-polar part of the steroid molecule the only part that's polar is the alcohol functional group whenever you see an o h bond or a c o bond that's the polar region of the molecule if you see a c h bond that's not polar so i'm just going to write that down the ch bond is nonpolar let me put np for nonpolar but if you see like an o h bond a c o bond or like a c n bond those bonds are polar and also the nh bond that's a polar bond as well now for answer choice d this particular steroid molecule is known as cholesterol b is the answer we're looking for b represents an amino acid so here we have a chiral carbon that is a carbon with four different groups and a typical amino acid will have this carbon it's going to have a carboxyl group or a carboxylic acid function group and it's also going to have an amino group a hydrogen atom but the part that differs in every amino acid is the r group which is here this is the part that changes everything else every other amino acids will have these four things the cairo carbon the hydrogen the carboxyl group and amino group now when the r group is a methyl group or ch3 group we have the amino acid called alanine number six which of the following represents a nonpolar aromatic amino acid so we'll need to analyze the r groups so for answer choice a notice that the r group only contains hydrocarbons there is no o h bond or nh bond so this is a nonpolar amino acid looking at answer choice c analyzing the r group we can see that there is a carboxylic acid functional group so this is an acidic amino acid and the carboxyl group is polar so this is also a polar amino acid so we can eliminate answer choice a and c a is nonpolar but it's not aromatic anti-choice b notice that we have an oh group so that makes it a polar amino acid which we're not looking for now answer choice d is the answer we're looking for the first thing is that it only contains hydrocarbons which means it's going to be nonpolar second we have a benzene ring so that is an aromatic ring so answer choice d is a nonpolar aromatic amino acid this is called phenol aniline abbreviated phe answer choice a this is known as a valine abbreviated v a out b is called serine the abbreviation is ser and for c that is aspartic acid abbreviated asp number seven which type of reaction occurs when two amino acids join together to form a peptide bond would you say it's a dehydration synthesis reaction an oxidation reaction a hydrolysis reaction a reduction reaction or none of the above well let's talk about what each one means an oxidation reaction occurs when there's a loss of electrons a reduction reaction occurs when there's a gain of electrons for this particular situation none of those reactions will apply now let's talk about dehydration synthesis and hydrolysis so when you think of the word synthesis what do you think of you're synthesizing something you're building something so let's say if we were to take two smaller units and combine it to form a bigger unit let's say a b this would be a synthesis reaction now when you hear the word dehydration what do you think of if you drink a glass of water you're going to be hydrated you're adding water to your body but let's say if you ran a marathon and you're sweating you've lost a lot of water you're dehydrated so dehydration has to do with the loss of water in this case water is going to be on the right side so this would be a dehydration synthesis reaction you're building something by means of by losing water hydrolysis is the reverse hydro means water lysis means to split apart so here we have the molecule a b and we're going to add water to break apart a b so that bond is going to disappear we're going to break the bond using water and we're going to split apart a b into a and b so that would be a hydrolysis reaction so a dehydration synthesis reaction will form a bond by means of the loss of water whereas hydrolysis will break a bond by means of putting water into the reaction now number seven we're trying to form a peptide bond we're not trying to break one so that's going to be a dehydration synthesis reaction now i'm going to give you an example so let's say this is the first amino acid here is the carboxylic acid group here is the r group and we're going to join it to another amino acid so i'm going to put r2 for a different r group so this is a dehydration synthesis excuse me i said that wrong a dehydration synthesis reaction so first we're going to lose water we're going to take out h2o two hydrogens and one oxygen atom and then we're going to combine these two units together and so here is the water molecule that was removed by creating the covalent bond so we created a carbon nitrogen bond here so this is the amide linkage you can see that's an amide functional group and this represents the peptide bond which is a type of covalent bond so anytime two or more amino acids join together they will always form a covalent peptide bond and they will create an amide functional group so that is a dehydration synthesis reaction we took two smaller monomers and combined it into a bigger molecule and we also lost water so that's it for number seven number eight which of the following is not a protein would you say it's hemoglobin myoglobin keratin collagen or testosterone hemoglobin is a protein that carries o2 in the blood myoglobin is a protein that carries oxygen or o2 in muscle tissues keratin is a protein that is found in hair and nails it's a structural protein and collagen is also a protein that is found in cartilage tendons ligaments and skin the answer is e testosterone testosterone is not a protein rather it's a hormone it's a steroid here's the structure of testosterone like cholesterol it has four fused rings which makes it a steroid it has a hydroxyl group a ketone functional group and it has a few methyl groups as well let me add the stereochemistry as well so that's the structure of testosterone it is the primary male sex hormone so anytime you see four fuse rings know that this is a steroid so that's it for number eight number nine which of the following is not an enzyme enzymes are proteins and you could easily identify an enzyme by looking at the suffix of the word if you see a word ending in ace it tells you that you're dealing with an enzyme lactase is an enzyme that converts lactose into glucose and galactose this enzyme it breaks down lactose into those simple monosaccharides protease is an enzyme that breaks down proteins into amino acids amylase is an enzyme that catalyzes the breakdown of starch and glycogen think of starches like amylopectin and amylose amylase can break down amylose and amylopectin into its glucose units lipase think of lipids lipase is an enzyme that breaks down fats fats like triglycerides into fatty acids and glycerol myosin is the only one that is not an enzyme whenever you see the endin in it's a good indication that you're dealing with a protein think of the other proteins that we've considered like hemoglobin or myoglobin or keratin so when you see the suffix in not always but generally speaking you're dealing with a protein and ace tells you that you're dealing with an enzyme number 10 which of the following is not an amino acid is it polymerase albumin ferritin insulin or histidine well we know that polymerase is not going to be the answer we can see the suffix ace that tells us that we're dealing with an enzyme which is a type of protein now polymerase is an enzyme that synthesizes nucleic acids such as dna and rna dna stands for deoxyribonucleic acid rna stands for ribonucleic acid dna is double stranded whereas rna exists as a single strand albumin is a protein that maintains the osmotic pressure of the blood ferritin is a protein that stores iron in the body and insulin is a protein slash peptide hormone that regulates the glucose levels in the blood notice that proteins they end with the suffix in albumin ferritin insulin and the last problem we said myoglobin hemoglobin think of the proteins actin myosin these two proteins they are involved in muscle contraction but you can see they have the same suffix in so when you see that it's a good indication that you're dealing with a protein now the majority of amino acids they end with the suffix in so think of valine which we've considered earlier serine tyrosine alanine most not all but most amino acids end with the suffix in so that's a good way to determine if you're dealing with an amino acid or if you're dealing with a protein or an enzyme which is also a protein so sometimes the name gives you a clue as to what the the answer is so that's it for number 10. number 11 which of the following statements is false so let's look at answer choice a first table sugar is composed of sucrose is that a true statement or is that a false statement this is a true statement b glucose is the main source of energy for cells this is also true glycogen starch they're all composed of glucose monomers c triglycerides are used for long-term energy storage this is also true for instance let's say if a person decides to fast if they decide not to eat for a while the first source of energy that your body is going to look to are your carbohydrates your sugars like glucose your stored carbs like uh glycogen that's the first thing that's going to go now within a day your body is going to run out of glycogen now once you burn out your carbs the next thing that your body is going to look for for energy are your triglycerides your fats and if you drink plenty of water a regular person can go days without needing food triglycerides they can provide you with the energy you need for many days without having a meal and so triglycerides they're very useful for long-term energy storage especially during periods of famine so fats are not always a bad thing now what about d saturated fatty acids are liquid at room temperature is that true or false so this is the false statement that's the answer we're looking for a saturated fatty acid which as you mentioned before does not have any double bonds these tend to be solids at room temperatures not liquids a good example would be like butter now there's two types of unsaturated fatty acids that you need to be familiar with the first one are the trans fatty acids you probably heard about that in the news that these are not good if you have them in your diet the other type which includes the vegetable oils these are usually better for your health these are the cis fatty acids they have a cis double bond and because of this kink in the structure the way it bends these types of fatty acids tend to be oily they tend to be liquid at room temperature so think of like a vegetable oil or olive oil they have this unsaturated cis double bond now here's a way in which you could distinguish the cysts from the trans double bond if you were to draw the hydrogen atoms notice that the hydrogen atoms are on the same side on the double bond in the case of a trans double bond the hydrogens are on opposite sides across the double bond so that's how you could distinguish whether you have a trans fatty acid versus the regular cis fatty acid now answer choice e we know has to be a true statement but let's talk about it cell membranes let me get rid of this first cell membranes are composed of phospholipids we know that has to be true so here is a simple way of drawing a phospholipid a phospholipid has a polar head and two nonpolar tails and they are used to form the cell membrane in a cell this is known as the phospholipid bilayer you have two layers composed of phospholipids in the interior of this phospholipid bilayer this is the hydrophobic region that's the non-polar region that's where your oils will prefer to be water doesn't want to be dissolved in that area this region is the polar region that is also the hydrophilic region and so water will be outside of that area and also below it as well but water doesn't want to stay in the interior of that region so that's the phospholipid bilayer which forms the membranes of cells now a phospholipid looks like this so it consists of a glycerol molecule two fatty acids one of them is saturated and the other one is unsaturated now it also contains a phosphate group and these are three methyl groups attach to the nitrogen atom whenever nitrogen has four bonds it's going to have a positive formal charge so that's uh the structure of a typical phospholipid so this phosphate group along with the the nitrogen and the three methyl groups that is the polar head of the phospholipid so that's the hydrophobic excuse me the hydrophilic region that's the part that is water soluble the other part of this molecule this is the hydrophobic region so this represents the two tails of the phospholipid this is the part that's nonpolar it's water insoluble it doesn't mix with water so just make sure you're aware of that so to review if you have a test just remember a phospholipid is composed of the glycerol molecule the phosphate group and two fatty acid tails one of them is saturated and the other is unsaturated number 12 which of the following statements is false let's begin with answer choice a dna is the macromolecule that stores the genetic information of a cell is that true or is that false this is a true statement dna is a nucleic acid it stands for deoxyribonucleic acid and yes it definitely stores the genetic information of a cell it tells the cell what type of proteins to make when to make them and other stuff like that now answer choice b enzymes are proteins that speed up chemical reactions that is true an enzyme can catalyze a chemical reaction it can make it go faster by lowering the activation energy another way to speed up chemical reactions is to raise the temperature but the human body operates at an ideal temperature of 98.6 degrees fahrenheit so you don't want to speed up chemical reactions by increasing the temperature thus enzymes are very useful part c a nucleotide consists of a phosphate group a ribose sugar and a nitrogenous base this is also a true statement so this would be the five carbon ribose sugar this would be the phosphate group and then we would have the nitrogenous base now this is a simple representation of a nucleotide the exact molecular structure will vary now this five nitrogenous bases that you need to be familiar with these are adenine thymine guanine cytosine and uracil now what you need to know is that uracil is found in rna but not in dna whereas thymine is found in dna and not rna now let's move on to part d lipids provided thermal insulation for animals in cold weather this is a true statement lipids have many functions they can be used for long-term energy storage they can be used as hormones in the case of testosterone and estrogen they're used to make the membranes of cells in the case of phospholipids and they can also provide thermal insulation for animals so animals with a lot of body fat this will help them to stay warm in the winter time now e has to be the answer looking for this is the false statement triglycerides are not soluble in water and let's talk about that so first let's talk about fatty acids earlier in this video i mentioned that fatty acids have a polar head and a nonpolar tail now even though this part is water soluble the bulk of the molecule consists of hydrocarbons and so overall because of the size of the non-polar tail this molecule by itself has a very very low soluble in water only a very small amount of it will dissolve in water so for the most part you could say it doesn't mix well with water so it's relatively insoluble now even though we have an oh bond typically when you see an oh bond that's a special case of hydrogen bonding and oh bonds are very polar they can increase the solubility of a molecule in water but because of this huge hydrophobic region it's not enough to make the whole molecule soluble in water so the solubility of fatty acids in water is very very very low now in the case of a triglyceride keep in mind the triglycerides have a glycerol molecule and three fatty acids let's add a unsaturated fatty acid and let's add a polyunsaturated fatty acid so notice that we have no oh bonds in this region the co bond is slightly polar but it's not as polar as in the which bond because there's no hydro there's no hydrogen bonds this molecule overall is nonpolar you have three huge non-polar cells and no oh bonds in this region so triglycerides are not soluble in water number thirteen which of the following molecules is not a lipid go ahead and try this so looking at ant's choice a this is known as a terpene specifically this is called isoprene this is a type of lipid so we could eliminate answer choice a b we could see that we have the four fused rings so this is a steroid which is also a type of lipid this is specifically called estradiol one of the major components of estrogen the primary female sex hormone now anti-choice d this is known as a prostaglandin it's also another type of lipid prostaglandins typically have a 5-carbon ring and a total of 20 carbons so if we were to count it this would be let's call this 1 2 3 4 5 6 7 and then 8 9 10 11 12 13 14 15 16 17. as you can see there's a total of 20 carbons i'm not counting it in any special order i just want you to see that there's 20 carbons in total and it has a 5 carbon ring so that's another type of lipid now anti-choice c represents an amino acid here we have our chiral carbon which has a hydrogen it has a carboxylic acid functional group an amino group and this right here is the r group so let's redraw in a way that is more familiar so let's start with the chirocarbon now we have the amino acid in its zwitter ion form if i take a hydrogen and put it here it's going to look like this so here's the carboxyl group of the amino acid here is the amino group this is the hydrogen and then the r group would be here it has a total of three carbons and an amide functional group so this particular amino acid is called glutamine so anytime you see a carbon atom that is connected to a carboxylic acid functional group and an amine you're dealing with an amino acid the monomer of a protein number 14 which of the following nitrogenous bases is not a pyrimidine now you need to know that pyrimidines they contain one ring so antichoice a is a pyrimidine c is a pyrimidine d is a pyrimidine all of these are nitrogenous bases now b has two rings b is what is known as a purine antichoice a is the nitrogenous base called thymine c is uracil keep in mind your cell is found in rna and thymine is found in dna d is cytosine notice the difference between thymine and uracil thymine has the methyl group your cell does not besides that everything else is the same now cytosine differs from uracil in that instead of having this carbonyl group you have an nh2 group so that's the difference between cytosine and uracil and also the presence of this double bond here so cytosine has one oxygen atom whereas thymine uracil those are pyrimidines with two oxygen atoms so to review the pyrimidines such as thymine uracil and cytosine they have one ring the purines such as guanine and adenine they have two rings now this particular purine for answer choice b which is the answer by the way this is called guanine so that's it for this problem number fifteen which of the following statements is slash are true number one macromolecules such as proteins may contain the element sulfur is that true or is that false it turns out that this is a true statement proteins are made up of amino acids amino acids are the building blocks of proteins they're the monomers of proteins and there's one particular amino acid that contain the element sulfur there's another one too but i'm gonna draw one of them so one of the amino acids that contain sulfur is known as cysteine the r group is ch2 sh so it has a thiol functional group this amino acid is abbreviated cys so if a protein has this particular amino acid in it which many proteins do since they tend to contain thousands of amino acids then yes they may contain the element sulfur number two the element phosphorus can be found in nucleic acids is that true or false now a nucleic acid has three components it has a ribose sugar and it has a phosphate group and it has a nitrogenous base such as the purines or the pyrimidines now because of the phosphate group in the nucleotide which are monomers of nucleic acids number two is a true statement so all of the nucleotides contain phosphorus so nucleic acids such as dna and rna which are polymers of nucleotides they will all contain the element phosphorus so anything that don't have one and two we can eliminate so we can eliminate answer choice d and e now let's focus on the ribose sugar there's a hydroxyl group on carbon three this is carbon one two three four five the ribose sugar is a five carbon sugar now in rna which is known as ribonucleic acid it has an oh group on carbon two so that would be the case for rna now for dna the situation is different dna stands for deoxyribonucleic acid so we're lacking an oxygen in the ribose sugar in dna so in dna on carbon 2 you have a hydrogen instead of an oh so just keep that in mind and that's how dna differs from rna the o h group is replaced with an h now let's move on to number three lipids do not contain the element phosphorus is that true or is that false number three is true for most cases most lipids do not contain the element phosphorus for example fatty acids only contain carbon hydrogen and oxygen the same is true for triglycerides they only contain c h and o i'm not going to draw all of it but just want to help you to see that even steroids with the four fused rings they only contain carbon oxygen and hydrogen now we do have phospholipids if you recall a phospholipid has the glycerol molecule two fatty acids one of which is unsaturated and it contains a phosphate group so phospholipids are lipids that do contain the element phosphorus so based on that number three is not a true statement it's false there are some lipids that contain the element phosphorus particularly phospholipids number four nitrogen can be found in nucleic acids monosaccharides and proteins this is true for nucleic acids a nucleic acid will have a nitrogenous base and as we've considered the purines and the pyrimidines they contain nitrogen atoms so you can't find nitrogen in nucleic acids you could also find nitrogen in proteins proteins consist of amino acids and every amino acid will have an amino group which contains nitrogen however monosaccharides like glucose fructose they don't contain nitrogen glucose is c6h12o6 galactose fructose they all have that chemical formula so monosaccharides contain carbon hydrogen and oxygen not nitrogen so number four is not correct that's a false statement so the answer is a one and two those statements are true number 16 which of the following statements is false let's start with a amylose is a polysaccharide consisting of glucose monomers connected by alpha 1 4 glycosidic linkages is that true or false this is a true statement now before we go into why that's the case we need to talk about a few things in its cyclic form glucose can exist as alpha glucose or it can exist as beta glucose as you can see the hydroxyl group is pointing up in its beta form and it's pointing down in its alpha form because glucose can convert into a straight chain form it can switch between its alpha and beta form and when it does that this process is known as meter rotation the carbon atom where it can switch between its alpha and beta forms that carbon atom is known as the anomeric carbon atom now amylose is basically a straight chain polymer of glucose monomers and we said that amylopectin is branched let's talk about why that's the case so in amylose this is the type of linkage that we have this is carbon one two three four five and carbon six is up here so notice that the linkage is between carbon one and four and because the bond goes down we have an alpha linkage so we have an out excuse me an alpha 1 4 glycosidic linkage in amylose and that's why amylose is straight but now let's extend this a bit in amelopectin the situation is different it forms branches let's see if i can fit this somewhere so in amelo pectin notice that we have this is carbon 6 by the way and alpha 1 6 linkage the alpha 1 6 linkage in amylopectin explains why there's a branching so the alpha 1 4 linkage creates monomers in a straight chain you have that in amylose amylose only has the alpha 1 4 linkage amylopectin has both the alpha 1 4 linkage and the alpha 1 6 linkage just keep in mind this particular glycosidic linkage is responsible for the branching that we see in amylopectin so that's a brief review into the bonding found in amylose and amylopectin now let's talk about the bonding in cellulose so for answer choice b it says that cellulose is a polysaccharide consisting of glucose monomers connected by beta 1 4 linkages and this is true so instead of the bond going down in the case of amylose it's going to go up in the case of cellulose so this is still carbon one on the ring to the left on the right we have carbon force so it's still a 1 4 linkage but we're dealing with a beta linkage so it's going to be a beta 1 for glycosidic linkage in cellulose so those are some things that you want to commit to memory or sometimes it's just better to understand it for the test so you have a beta 1 4 linkage in cellulose and alpha one for linkage and amylose and in amylopectin it's alpha one four and alpha one six now let's move on to part c the primary structure of a protein is determined by its amino acid sequence this is a true statement that's one of those things you need to know and for d chaperonins are proteins that help new proteins to fold properly that is also true so we know that e has to be the false statement but let's talk about it the tertiary structure of a protein is characterized by formation of localized structures such as the alpha helix and the beta pleated sheet this is true for a secondary structure and not the tertiary structure so let's review this from the beginning the primary structure of a protein is determined by its amino acid sequence the secondary structure of a protein is based on the alpha helix structure that it and the beta pleated sheets now the tertiary structure of a protein is based on how the polypeptide chain folds so it has to do with the folding of the chain and its 3d structure now sometimes you may have a protein with multiple subunits multiple polypeptide chains coming together to form a functional protein so thus that would represent the coronary structure so if you have a protein with multiple polypeptide chains then that combined structure would be the coronary structure in the case of hemoglobin hemoglobin has four polypeptide chains it has two alpha subunits and two beta subunits so those four chains combined would form the quaternary structure of hemoglobin so those are the four levels of structures that you need to know as it relates to proteins so that's it for this video for those of you who like it don't forget to subscribe and thanks again for watching