1.4&1.5-AminoAcids&Proteins Flashcards
What are the 3 positive AA’s?
HAL! Histidine, Arginine, Lysine
What are the 2 Negative AA’s?
GA! Glutamate, Aspartate
How large of a change in scale for changing 1 full unit of pH? Ex. pH7 to pH6…
10x differnce. (pH=7 = .0000001mol/L to pH=6 = .000001mol/L)
High Ka=?pKa?
High Ka=Low pKa (logarithmic relationship)
Low pKa=?pH?
Low pKa=Low pH (strong acid)
What is the Henderson-Hasselbalch Equation?
pH= pKa + log [ConjBase] / [Acid]
Concerning the HH Eq relationships: what happens to the relationship of pH to pKa if we add base to the solution?
pH > pKa (adding numerator log [A-] / [HA]
Concerning the HH Eq relationships: what happens to the relationship of pH to pKa if we add acid to the solution?
pH < pKa (adding to the denominator log [A-] / [HA])
What does pKa tell me about how much dissociation has occurred?
pKa = 50% dissociation
Where does aspirin (pKa=3.5) get absorbed? Stomach (pH=1.5) or S.I. (pH=6.5)
Stomach (pH 1.5). Here, the aspirin is very associated, so it is not charged, so it can pass the membrane.
What % dissociation occurs when you have a 1 pH unit above the pKa?
91% dissociation
What % dissociation occurs when you have a 1 pH unit below the pKa?
9.1% dissociation
What is the average of the pKa surrounding the zero charge point?
pI-isoelectric point
What are the polar and charged (+&-) AAs?
HAL (+) (Histidine, Arginine, Lysine), GA! (-) (Glutamate, Aspartate), and (Polar) St. AG Cystine chapel (Serine, Threonine, Asparagine Glutamine, Cystine)
How are amino acids typically read?
N to C
What secondary structure is silk an example of?
Beta sheet
What category of protein structure incorporates “bends” when a backbone can fold on itself?
Secondary Structure
Which protein structure category deals with folding and 3D structure via hydrophobic/plolar/hbonding type interactions?
Tertiary
Which structure is defined by having multiple subunits?
Quaternary
Fibrous VS Globular: Which is water soluble? Which lacks tertiary structure?
Globular is water soluble. Fibrous is water insoluble and lacks tertiary structure
What is the pH of the carboxyl portion of an AA?
2
What is the pH of the Amino portion of an AA?
9
