Amino acids, proteins Flashcards
L amino acid correspond to
S configuration (except cysteine)
what side is amino group on for an L amino acid
Left
nonpoar
glycine, alanine, isoleucine, leucine, methionine, vaine and proline
tryptophan and phenylalanine
what is the nonpolar aa that i always forget
proline ( structurally nonpolar)
aromatic amino acids
tryptophan (2 ring- typically non-polar), phenylalanine, and tyrosine (polar)
polar side chains
serine, threonine, glutamine, asparagine, cysteine
asparagine or glutamine longer
glutamine ( later in the alphabet)
they are both amides
whats unique about the amide groups of glutamine and asparagine
they do not gain or lose a proton with changes in ph
histidine at physiological ph
its side chain has pka of 6 so at physiological pH it is neutral, need to be in more acidic enviroment and second
at pH 0 = +2 ph 4= +1, ph 6= 0 ph 10= -1
strongly hydrophobic
A, I, L, V, F (FAIL V) found in inside
hydrophilic
charged - H, R (arginine), K (lysine)
glutamate (E), and aspartate (D)
glutamine (Q) and asparagine (N)
glutamate
E
aspartate
D
Q
glutamine
N
asparagine
K
lysine
W
tryptophan
Y
tyrosine
peptide bond
amide bond- condensation or acyl subsitution rxn
amino is Nu and attaches tha carbonyl carbon, then hydroxy group is kicked off = amide bond
cystine
has a sulfur bone
high electron affinity means
large amount of heat released when an atom gains an electron - means large delta G (halogens are the most)
hesses law
energy is a state variable
energy change is independent of path
so use this is you know the delta H of formations of all reactants and products
delta H of rnx= sum of delta Hf of produucts - sum of delta H reactants
what do i have to remeber to do when using hesses law
that the delta H f is given per mol of substance so need to multiple by the mols in reaction - make sure balanced
in a concentration cell, where is the concentration greater at the beggining? example Ni 2+
since electrons travel anode to cathode
there would have to be more cations at the cathode bc electrons will run unitil in equilibrium
do bacteria and aercha have nucleus?
no
they have no nucleus or membrane-bound organeles - they have circular DNA
bacteria has peptidlglycan cell wall aercha does not!
desmosomes vs tight junctions vs gap junctions
desomsomes- tensile strength by anchoring cytoskeleton -specifically the intermediate filaments together (found in skin with high levels of mechanical stress)
tight= prevent water and solutes from dissolving through- serve as a barrier
gap= mediate communication
reducing and non-reducing SDS-page
reducing means that a reducing agent is added - this can break disulfide bonds- so peptides will seperate into individual peptides
if compare reducing and nonreducing sds-page can see if a protein had covalent bond (disulfide bonds)
when does ATP come to muscle contraction
right after power stoke ( ATP binds after release the myosin head)
ATP hydrolysis for the energy needed to pull myosin back to high energy position ( so it is ready for another stroke)
when Ca enters myosin can bind
ADP +P is released and power stoke happens
