eLa Online Assignments Flashcards
What is roughly the pKa of Asp/Glu sidechain residues?
They are roughly 3.5-4.0
What is roughly the pKa of Lys/Arg residues
10.5-12.5
What is the pKa of histidine?
pKa - 6.1
What is unique about glycine in regards to proteins?
Glycine has a small sidechain so proteins can adopt a wide array of conformations and are considered flexible
What is unique about proline in regards to proteins?
Very rigid and tends to form kinks in the protein
Not often found in alpha helicies and B-sheets
What are unique about cysteine residues in regards to proteins?
Cys residues can form disulfide bonds with each other
This is the only common covalent bond that is formed between sidechains
What are the non covalent interactions of amino acids
Ionic Interaction, hydrophobic interactions, hydrogen bonds
What is an noncovalent ionic interaction?
Charged molecules may be interacting with other opposite charged molecules
Aspartic acid interacting with lysine
What are noncovalent hydrophobic interactions?
Hydrophobic side chains that group together. Usually toward the center of the protein
What are noncovalent hydrogen bonding?
H-bonds can form whenever a strongly electronegative atom approaches a hydrogen atom
What is a strong acid?
An acid that completely dissociates in water
What is a weak acid or base?
Weak acids or bases do not completely dissociate in water, thus they are give characteristic dissociation constants to describe their behavior
What is the definition of pH?
pH is defined as the negative logarithm of the concentration of H+ in solution
What is the Ka of a solution?
Ka is the acid dissociation constant of a weak acid
What is pKa?
-logKa
What is a buffer?
Buffer is a solution containing and acid and its conjugate base that is resistant to large changes in pH
What is buffer capacity?
A quantitative measure of the resistance of a buffer solution to pH change
What does the henderson-Hasselbalch equation describe?
The equation describes the relationship between the pH of a solution and the relative amounts of a conjugate pair in that solution
How does the body compensate for changes in acid-base status?
Weak inorganic acids are especially critical for buffering biological fluids. The phosphate system helps buffer the cytoplasm
At what pH would serine have a fully pronated side chain?
At pH of 2.0, the lower the pH the more H+ ions present that will attach itself to the side chain
Why is SDS-PAGE more appropriate for electrophoresis of integral membrane proteins than native gel electrophoresis?
The detergent nature of SDS prevents aggregation of the membrane proteins that might occur in a native gel
What does having a high membrane:volume ratio and biconcave shape allow the erythrocyte to do? Where does this shape come from?
The biconcave shape allows for the erythrocyte to be flexible. The extra membrane allow them to squeeze into small capillaries. The shape comes from the attachment of the plasma membrane to the cytoskeleton.
What type of filament does actin form?
microfilament
Sphingomyelin is what type of membrane lipid?
Phospholipid
What important distinguishing feature are on the outside of the RBC?
ABO an Rh systems
How could you describe the permeability of a RBC to water? How must this be taken into account when formulating IV mixtures?
An RBC is highly permeable to H2O due to the presence of aquaporins. When formulating IVs they must contain the same level of solutes as inside the cell.
What would comprise a hypotonic IV solution?
More water and less salt than the cytoplasm of a normal erythrocyte
What would comprise a hypertonic IV solution?
More salt and less water than the cytoplasm of a normal erythrocyte
What are characteristics of hereditary spherocytosis?
Improper sodium transport and decreased membrane to cell volume ratio. Defects in the proteins that connect the membrane to the cytoskeleton