AAMC FL 5 B/BC QUESTIONS AND ANSWERS

Adaptive immunity - Answer- specific Two types of adaptive immunity - Answer- Humoral immunity- B cells regulating antibodies Cell Mediated Immunity- T cells regulating innate immunity - Answer- non-specific phosphodiester linkage - Answer- covalent bonds that join adjacent nucleotides between the -OH group of the 3' carbon of one nucleotide and the phosphate on the 5' carbon of the next disulfide bonds - Answer- 2 cysteine residues can covalently bond to form disulfide bonds which hold together tertiary structures if sufficient cysteine residues are available. Heat can disrupt these bonds Hydrogen bonds - Answer- hold base-pairing nucleotides together, not nucleotides within a backbone. Glycosidic linkages - Answer- bind carbohydrates together pI - Answer- pI is the pH at which the overall charge is neutral - A matches this definition for NqrD, since equal cationic and anionic functional groups would cancel out to 0 net charge. At a pH greater than the pI, you can think of it as there being relatively low proton concentrations in the environment, so the molecule is deprotonated (more negative). Conversely, at a pH lower than the pI, you can think of the environment as being relatively highly concentrated in protons, so the molecule is more protonated (more positive). Ionophores - Answer- Ionophores are compounds that bind to ions and facilitate their movements across membranes. succinate dehydrogenase - Answer- succinate to fumarate FAD to FADH2 Isoelectric focusing - Answer- separates proteins based on their pIs. The technique uses an electric field and a pH gradient which causes proteins to stop moving at a pH equal to their pI. Southern blotting - Answer- Southern blotting is a technique to identify specific DNA fragments and does not require a pH gradient. Proteo