nemzy

Can anyone correct me if im wrong? This is basic basic basic basic basic basic biology, and i am just trying to refresh my memory and make sure that i am stating the correct facts 1) General concepts about tonicity ---- Lets say for example, we have a red blood cell exposed to solutions of different tonicity (hypo, iso, hyper) If the red blood cell was hypotonic to the solution, then the red's blood cell volume will increase, and ultimatey lysing the cell. If the red blood cell was iso to the solution, it will make no differenfce If the red blood cell was hyper to the solution, the cell would shrivel as water will leave the cell and thus losing volume in the red blood cell. 2) Lets say for example, the isotonic concentrations for the red blood cell's was exposed to different solution of increasing osmlarity but equal concnetration. If this was to happen, osmosis would be in equilibrium, since osmosis is only determnined only by a difference in total solute concentration, nut just spefically different solutions. 3) If polar molecules of increasing molecular weight was introduced to the red blood cell plasma membrane, then how would the rate of transport across the red blood cell membrane change? Well, first of all , it is very hard for a polar molecule to pass thru the membrane, let alone the size. So, the rate of transport across the red blood cell membrane would greatly be reduced. So am i stating the correct facts. Or are they any more stuff that can be added to my concepts? If im wrong anywhere, can you show me where and why? thanks

its the substitution of hydrogen on a benzene ring by molecular bromine acetanlide + Br2 ---> 4-Bormoacetanilide +HBr

If each molecule of acetanilide produces one molecule of hydroge bromide, what volume of HBr gas should be evolved from the reaction? So to solve this, ONE molecule of acetanlide will produce ONE molecule of hydrogen bromide... then, the molecular weight of hydrogen bromide produced will have a mass of 82 grams... Ok, am i doing this problem correctly so far? So what step do i have to go to next, i am confused on how to approach this problem, thanks

If you increase the substrate concetration, then the enzmatic reation will increas right? If you alter the pH affect of an enzymatic reaction,then the enzyme will denature right? are my concepts right ? also, If you pretreat an enzmye with high heat, how will it affect the rate?

how do we know if a molecule is optically active? does it have to do something about R,S configurations? I have no idea, what it is...and how to know whether a molecule is optically active or not thanks

what is a disadvantage of using diffential staining (dyes to increase the speciman's contrast) in light microscopes?

which of the following will most likely be disrupted by a change in pH? 1) hydrogen bonding 2) ionic bonding 3) hydrophobic interactions 4) disulfide bonds 5) neither -I'm pretty sure its not 1) and 2) since changing the pH won't affect the electronegativity of an atom...Pretty sure that its not disulfide bonds either, so from that im guessing that its hydrophobic interactions..am i right? or is my concept wrong? A nucleotide containing a purine, ribose, and a phosphate group could be a building block for? a) dna b) mRna c) tRna d) rRna e) b,c,d -Ok it is NOT A for sure, so im assuming that a nucleotide contaning a purine, ribose, and phosphate group could be a building block for all b,c,d....am i right ? or am i missing an important concept? A DNA molecule with 5'ATCGTAC3' = 3'TAGCATG5' right? If one thousaidn glucose molecues arrive in a cell, and the 1000 glucose molecules join together into a starch molecue, what changes occured with the synthesis of the starch molecule? -well this is an anabolic pathway since we are building something small into something bigger. So entropy decreases, since this is a non-spontaneous system. However, does the entropy of the universe decrease, or the entropy of the cell decrease? Dehydration syntehisis will decrease entropy within a system right? since its the formation of smaller molecules into bigger ones?

Why is it necessary to use a large excess of acetic adic in the prepartion of isopentyl acetate?

1) how many moles of h2 gas should be taken up by 1 octene in the courseof this reaction? CH3-(CH2)5-CH=CH2 -> (H2PtCl6) -> NaBH4, C2H5OH, HCL -> CH3-(CH2)5-CH2-CH3 Answer is 2 right??? 2) What volume does this correspond to at STP? How can i solve this part? 3) how many moles of molecular hydrogen are consumed per mole of the precatalyst (H2PtCl6) in order to convert it enterily to platinum metal? Isnt this 2 also?? what is the diff between this and the moles of H2 gas for the question #1? 4) How many moles of precataylst (H2PtCl6) are used in this reaction? Again is isn't this 2?? My answers don't seem right and i am still a little dubios before submitting them...am i misunderstanding a simple concept here? thanks

thx

ok, well here is the exact details of the problem: which fatty acid melts at the highest temperature (solid to liquid) (order from lowest to highest temp required to melt) Don't know how to draw on here, so i will just explain it to you 1) a 17 long hydrocarbon chain with a Carboxyl group attached at the end. Has no double bond 2) a 17 long hydrocarbon chain with a Carboxyl group attached at the end. Has 1 double bond 3) a 17 long hydrocarbon chain with a Carboxyl group attached at the end. Has 2 double bonds. My guess is that 1 requires least and 3 requires most temperature

how many diff polypeptides, each composed of 5 amino acids, could be synthesized using the 20 common amino acids? the answer is simply 20^5 right? if not, then can u please tell me what im doing wrong thx

okay, i understand how these reactions works and in which circumstances, but there are some general concepts that i am confused about. first of all, i know that in Sn2 reactions, generally weak bases are best as nucleophiles..but how can you know what a weak base is? for example, why is CH3CO2- a weak base (sn2 will predominate) and CH3CH2O- a strong base (E2 will predominate)? And..how can u tell what is an aprotic or protic solvent? for example, CH3OH is protic, but CH3CN is aprotic?

why is that a (Z)-2-chlorobutenedioc acid reacts MUCh faster than a (E)- configuration?

is it posssible to do a dehydrohalogenation of Cl using KOH, ethanol instead of NaNH2, NH3. for example: CH3-CH2-CL-C (double bond) CH-CH3 ----> CH3CH2C(triple Bond)CH On the midterm, i put KOH, ethanol, but i got it marked incorrect and the right answer was NaNH2, NH3...but when i read the book, it said either NaNH2, NH3 or KOH, ethanol is possible? somebody help me out here?