got more MCAT practice questions for you guys all right I'm going to show you guys how to pick the best answer and I'm going to explain to you guys why the other answers are wrong and what you need to know when you're going to take the test okay I'm going to give you guys some background information of what you need to know all that stuff all right for those of you that don't know me my name is Eric and I'm on a mission to make sure this MCAT as easy as possible for you guys all right real quick let's do this this is question number 14 do it on your own first and then hear me break it down and see you know if you got them all right you know I hope you got them all right this is the MCAT sample test as well all right is this a spoiler yeah it is a spoiler but to be honest a sample test is nothing compared to the real test okay I've gotten plenty of students that say the same exact thing all right sample test is probably the easiest one okay not even guys you should be studying your asses off because not even like the fls are being representative of the real exam I've heard plenty of stories of students that just got like destroyed on the real test thinking that you know they're fls and where the thinking of the fl's really very similar to the real exam so you guys gotta prepare for War okay prepare for war take the MCAT once and yeah that's all you got to do guys all right so study hard so do this on your own first this is question 14. this is question 15. question 16 and question 17. all right I'm gonna do this real quick let's jump in the structure of the tri terpene squalene is shown squalene is produced in the human body as a precursor to which important class of compounds all right you should know what this is you should know what terpenes are you should know what makes terpenes okay isoprenes make terpenes terpenes make cholesterol and cholesterol can make steroids steroids and you know steroid hormones Okay so you should know that and you should know this is going to make steroid hormones okay triaso glycerol is you know the structure of that that's just a glycerol with Three fatty acids esterified to it you should know what a sterified is phospholipids um so it's a phosphate and a fatty acid okay there is no phosphate here so you should eliminate beef lemonade a prostaglandins you should know what prostaglandins are you don't have to go too much in depth that's very very low yield all right it's literally just a fatty acid it's made of them arachidinoic acid and in order to know that it's a prostag linen you should see a five carbon ring on it okay and they're long prostate glands are like 20 carbons long they're pretty long okay so the only one that makes sense here is number non number letter C okay tell me down below if you need any help on any of these questions guys I got you question 15. what is the concentration of Cl minus ions in a 0.1 molar solution of calcium chloride all right guys I always recommend you guys to actually read the words in the question all right like literally it says ions so what does that mean that means something is being broken down into its constituent ions all right calcium chloride is being broken down into its ions so as soon as I see this I'm going to think something dissolves all right so c a cl2 dissolves and is broken down to its ions like I said so you have ca2 plus what the hell is this get away and you have two CL minus ions in here okay and they told us that we had a 0.1.1 molarity solution of calcium chloride so this is going to be 0.1 molarity and this is going to be broken down and we're going to get a concentration of 0.1 molarity of calcium ions okay why is it 0.1 well it's 0.1 because there's only one of these okay there's only one mole of calcium ions here but in the chloride ions we have two and we have two CL minus ions per cacl2 that's broken down so it's not going to be 0.1 it's going to be 0.2 all right now Eric how the heck because it's a common common question that people ask me how the heck do we go from point one all right we have point one how do we go from point one to point two how does that make sense at all all right well guys it's broken down okay it's broken down so think about think about like this all right and if you understand this already in your master list then you can go ahead and skip this part all right but let's say you had a bicycle okay let's say you had a bicycle this is your bicycle here all right this is the tires this is the frame okay and let's say I put this bicycle in water and that water magically broke the bicycle apart okay when I put in water we're gonna get the frame here and we're going to get the two tires here okay these are tires all right I had one mole of bicycle in a liter of water in the beginning so I had one molarity of bicycle okay that broke down now if I ask you hey what is the concentration of tires in the solution all right well the concentration of tires in the solution is going to be to molarity right we have two tires we have two moles of tires over that same leader so we're going to have two molarity that is a concentration of tires the concentration of the frame is one molarity okay just because you know this is point one it could also become 0.2 when it's broken down all right we're not adding any water we're not getting rid of any water there's still one liter in the beginning and there's still one liter at the end the only thing that I'm asking you for the molarity of the tires the only things that I'm asking you for the molarity of Cl minus ions okay make sure you guys understand that that's pretty it's pretty high yield I'd say so 0.2 is the answer here question 16 addition of which disaccharide to a solution of ag2o and NH3 will not result in the deposition of shiny silver mirror on the walls of the reaction vessel okay low yield but you must understand this all right when you see this you should think all right if you do not know what this is you got to review your carbohydrates all right this is tolan's reagent well what the heck is tones reagent well this is told it's reagent real quick all right tones reagent what they do is they grab silver oxide that's what this is called and they put it into a solution of ammonia all right they mix this and they get a g um nh32 plus okay they get this molecule here and they use this molecule to see if there are any reducing sugars present okay so let's say we had a reducing sugar present if we had a reducing sugar present that reducing sugar will reduce this it will give an electron to this okay reduce reduction is gaining so this will get reduced all right and uh all you have to know is that when this gets reduced when it gets that electron it's gonna a silver powder will form or silver color okay if this does not get an electron no electron okay that means there's no reducing sugar present there's not going to be any silver okay so the only way we're going to get silver if is if there's a reducing sugar present okay that's how it checks now they're asking you which will not result in the deposition of shiny silver mirrors so which is not a reducing sugar because if it not a reducing sugar it will not produce the silver alright so how do I know if a sugar is of reducing sugar well if it has a Hemi acetal group on it all right so what is a hemiacetal group well this right here is a hemicidal group okay if you're looking at this carbon here a hemicidal group has that alcohol okay as an oh here it's got an o with an R Group it's got an ether okay it's got an R chain here so carbons and it's got a hydrogen here all right I'll write it out here so it's a little easier for you guys to see all right this is a Hemi acetal group you must understand this all right it's o h there's an H here all right the placement of these they don't really matter so you have an o you have an R here as well okay R Prime and then you have a different R Group here I'll make this R2 here that is your Hemi acetyl group know it so let's see here we have the oh the o the r yup this is a Hemi acetal group okay this one is the same thing as this literally the same thing so this is a hemi-acetal group this one again oh our group hydrogen this is a hemiacetal group hemiacetal group here I'm acetyl group here Mac talk group here these are all reducing sugars let's look at this guy sucrose this is not a Hemi acetyl group Eric why is it not one well we have the o we have the r chain here but we don't have an oh directly connected to this okay there's carbon and Deno weights we need a straight up straight o h okay not carbon and then a weights all right you should also memorize that sucrose is a non reducing sugar so therefore the one that's not going to make the shiny silver is d all right let's keep going what is the net charge of the peptide Arginine alanine phenomena leucine at ph8 PHA is very you can treat pH 8 as you would pH 7 okay it's a very neutral pH so once you get a pH 9 then you gotta start memorizing some side chains and start you know getting a little complicated there but ph8 very neutral treat it as these amino acids as such okay so Arginine you know it's a positive amino acid so we have a plus one here so far it's plus one alanine is neutral phenylalanine is neutral leucine is neutral the total net charge okay net meaning the total charge is plus one bamc all right and I'm gonna okay so that's it so I'm gonna comment down below if I got all these right comment down below anything you guys want me to make a video on any lessons tutorials whatever and uh yeah see you guys the next one