BCMB20002 Lecture Notes - Lecture 3: Guanidine, Histidine, Amine
6 Mar 2017
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How to memorise the structure of amino acids r-groups. Grouping the amino acids: hydrophilic (charged, polar) Basic, amine in acidic solution, pick up a proton and become positively charged. Hydropho(cid:271)i(cid:272)ity as it"s a longer hydrocarbon chain protein (hydrophobic inside compared to hydrophilic outside) Amine group gives it hydrophilic state (like carboxylate) can do work. At the end is a planar guanidinium group resonance structure. Make good hydrogen bonds between proteins and dna. Alkane chain, hydrophobic in nature hydrophobic interactions. Planar resonance structure through all 5 bonds. Pka can increase we=hen h is lost. One of the h can stabilise on one of the n. 3 tautomers, when both n is protonated, or one is protonated but the other is stably protonated. Ligates to metal ions: hydrophilic (neutral, polar) Extreme ph conditions, h can be ripped off. However, biochem (due to stable ph) says the h on the amide or hydroxyl is relatively stable.
