Exam 1 Flashcards
Which bonding forces involves the electrostatic attraction between two molecules with partial charges created by induced dipoles along bond axes? Or molecules in close proximity?
LDF
Which of the sets of two amino acids below would represent a conservative
substitution if one were to replace another in a protein?
Find the amino acid pair that are both nonpolar, polar, or ionizable
What is a common property of the side chains of the amino acids shown above?
Classify if they are all nonpolar, polar, or ionizable. If they’re all nonpolar, they can be buried inside of a protein structure
What type of bond is formed between the side chains of two cysteine residues?
Covalent bond
Micelle
Hydrophobic interior and hydrophilic exterior
Which bonding force is most important for the localization of hydrocarbon side
chains when fatty acids are forming a micelle structure?
Hydrophobic interactions
Which of the molecules below form bilayer structures when dispersed in water?
Phospholipids
If temperature drops, a phospholipid membrane becomes too rigid. How can fluidity be achieved again?
Either decrease the amount of carbons or increase the amount of double bonds
If temperature raises, a phospholipid becomes too fluid. How can rigidity be achieved again?
Either increase the amount of carbons or decrease the amount of double bonds
Which amino acid when substituted for another amino acid in a reverse
turn would be most likely to result in a pathogenic mutation?
Tryptophan. Typically you want small side chain amino acids for reverse turns, such as glycine, alanine, and serine
Which of the peptides below would segregate hydrophobic residues to a
single surface of an beta helical structure?
Find the amino acids that are NP, P, NP, P, NP, P this will create beta pleated sheets
Which bonding force would form between the side chains of arginine and glutamic acid at pH 7?
Ionic bonds- the N+ from R and O- from Q will ionically bond
Which amino acid begins the synthesis of proteins specified by the genetic code?
Met- codes for AUG which is the start codon
Which amino acid replaces glutamic acid at position 6 of beta chains in sickle cell
disease?
Valine
Which amino acid has an isoelectric point of 10?
Lysine. Must find an amino acid that has a pKa similar to the isoelectric point
pKa of Histidine (His, H):
6
pKa of Lysine (Lys, K):
10
pKa of Tyrosine (Tyr, Y):
10
Which interaction between functional groups of the polypeptide backbone plays a critical role in stabilizing alpha helices?
N-H and C=O
Anfinsen’s experiment involving ribonuclease denatured with urea showed that…
Proteins are capable of folding into complex three-dimensional structures capable
of functioning properly solely through the interactions of a polypeptide chain with the
aqueous environment. Proteins, once denatured, are able to refold back into their original form.
What is needed for a polypeptide chain to fold into its native three-dimensional structure?
Interaction with an aqueous environment
What is inhibited by 5’-fluoracil?
Synthesis of dTMP
What would be prevented by inhibiting the
the activity of tRNA synthetases?
Addition of amino acids to tRNA’s
Translation is the biochemical process that results in the synthesis of?
Proteins, polypeptides, ubiquitin, etc
