MCAT biochemistry Proteins / Amino Acids Flashcards
What are the functions of proteins
enzymes hormones receptors channels transporters antibodies and support structures inside and outside the cell
what is the generic amino acid structure
alpha amino group H2N »_space;alphcarbon to C(H) R»_space;»> CooH alpha carboxy group
all twenty amino acids share the same nitrogen carbon to carbon backbone
unique feature is it side chain
what are the classifcation of amino acids what shouold with be familar with the side chains for the mcat
you should be familiar with their side chain and it important to understand chemical properties shape ability to hydrogen bond and act as acid or base and physiology pH
What are the 4 basic categories of amino acids
acidic basic nonpolar and polar amino acids
each amino acid has a 3 letter abbreaviation and one letter abbrevation with are both important to know for the mcat
what are the classification the one letter and 3 letter abbrevation of each amino acid
asparatic acid =ASP=D acid
Glutamic acid GLU =E acid
Basic amino acid
Lysine =K = LYS =basic
Arginine Arg =R
Histindine =His =H
Hyrodrophpic amino acid Hyrophobic=nonpolar amino acid Glycine =Gly= G AlANINE =Ala=A Valine = Val =v Leucine =Leu=L Isoleucine =ILE I phenylalanine =Phe=F Tryptophan = trp=w
Polar amino acid Serine =s = ser Thereonine Thr=T Tyrosine =Try =y Asparagine Asn =N Glutamine Gln =Q Cysteine =Cys = C sulfur containing MEthionine =MEt=M Proline =Pro=P = important for protein folding
what are the acidic amino acids what are their function al groups
asparatic acid and glutamic acid are the only amino acids with a carboxy functional group of Pka=4
3 functional groups that may act as acids
you may hear fo term asparate and glutamte simly refered to the anionic ( deprotonated) form of each molecule
Reminder
Asparactic Acid Asp =D Ch2cooh
Glutamic acid =Glu=E Ch2Ch2CooH
asparate and glutamate simply refer to anionic deprotnated form of a molecule in its physology ph
what are the basic amino acids TEST Question ON MCAT 1
; Lysine arginine and histidine have a basic R group
pka side chains
LYS 10, Arg 12 and 6.5 For His
Both Lys and Arg are catonic ( Protonated ) at physiology pH 7.4 Histidine may be either protonated or deprotonated- we put basic category
- COOH or NH2- are side chains , always anionic ( RCOO-) or catonic (RNH3+) at physiology ph
Lysine LYS =K Ch2Ch2Ch2Ch2Nh2
ArGinine Arg=R= CH2Ch2 Ch2 NH(N2H)2
Histidine Naromatic N H ring penta ring with 2 nitrogen with H
Hydrophobic (Nopolar ) Amino acids TEST QUESTION IN MCAT 2
aliphatic akyl or aromatic side chain amino acids with aliphatic side chains include glycine, alanine , valine leucine and isoleucine phenylalanine tryptophan and tyrosine
hydrophibic residue tend to associate with each other rather than with water on the interior of folded globular proteins away from water
The larger the hydrophobic group the greater the hydrophobic force repelling it from water .
Gycine G -Gly=H Alanine A Ala= Ch3 Valine val =V= Ch3 Ch3 Ch3 Leucine =L =leu Ch3 Ch3 Ch3 Ch3 Isoleucine ILE ICh Ch3 Ch2 Ch2 Phenealin Phe =F Ch3 Benzene Tryptophan Trp=W ch3 benzene and pen nitrogen ring
what is isoelectric
The isoelectric point (pI, pH(I), IEP), is the pH at which a particular molecule carries no net electrical charge in the statistical mean. The standard nomenclature to represent the isoelectric point is pH(I),[1] although pI is also commonly seen,[2] and is used in this article for brevity. The net charge on the molecule is affected by pH of its surrounding environment and can become more positively or negatively charged due to the gain or loss, respectively, of protons (H+).
What are Polar Amino acid ? TEST QUESTIOn MCAT3
Polar enough to form hydrogen bonds with water but does not act as a acid or base
hyrophilic whenever possible
Hydroxy group of serine (Ser=S Ch2OH) (theronine= Thr =T Ch3ChOH )and( tyrosine = Tyr= Y aromatic benzine Ch3 with OH group ) Ch3 benzine ring with oh residues are often modified by the attachment of a phosphate group by a regulatory enzyme called kinase the result is due to the very hydrophillic phosphate group.
the other include amide dervatives of asparatic and glutamic
you have sulfur containing amino acids cysteine and Met=M methione ch2ch2SCH3 cystheine Cys =C contains CH2SH
Proline =P=Pro unique feature
What are the essential amino acids
Lysine Histidine , Threonine, Valine , Leucine, Isoleucine, Phenylalinine Trypptophan and Methionine
what is the amino acid reactivy the result of
amino acids are reactive from their carboxylic acid groupd and thaeir amine group
What is the reactive chacteristic of proteins?
Proteins are amphoteric ( act as acid or base) bc their carboxylic acid group and amino grop
carboxyl group of amino acid is about a 2 while while the amino acid is have the pka of 9 or 10
NH3»»»> ««< NH2 + H pKa=9
-COOH»_space;»>««_space;COO- +H PKa=2
