Midterm one - to remember

Question 1

w methods for separation based on size

Answer 1

gel filtration
centrifugatin
dialysis
ultrafiltration

Question 2

what gets eluted in gel filtration?

Answer 2

larger molecules first

Question 3

compare and contrast epimerases and racemases?

Answer 3

they both catalyze the steorochemical inversion of substrates

• racemases act on substrates with ONE chiral center
• epimerases act on substrates with more than one chirla center

Question 4

principle effect of adding organic solvent to precipitate enzymes?

Answer 4

reducing water activity
reduces the solubility, by decreasing the dielectric constant of water, making the protein less soluble in water–> the thin film around the protein is disrupted and the protein precipitates

Question 5

at low salt concentrations what happens to protein solubility?

Answer 5

increased bc the salt stabilizes the protein structure–> keeps/pulls the hydrophilic aa’s on the outside, which promotes their interaction with water molecules

Question 6

what happens at high salt concentrations

Answer 6

less soluble bc water now wants to interact with salt instead of protein, the protein structure is destabilized and interacts with itself through hydrophobic intereactions

Question 7

lyases

Answer 7

break one molecule into two with formation of a double bond