EXAM REVIEW 1 - Spring 10 25. (4) Glutamine in its fully...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Spring ‘10 25. (4) Glutamine in its fully protonated form is placed into solution and titrated to its isoelectric point with NaOH (a) How many moles of base is(are) required for this titration starting with one mole of glutamine?. 25. a) 1; b) α carboxyl 27. (4) What is the driving force for the formation of hydrophibic interactions? 27. Water can no longer form an iceberg-like cage around the hydrocarbon tail. Rather the water is randomized. The driving force for hydrophobic bond formation is entropic. 29. (6) Outline the general strategy for gene cloning. Why are two selectable markers typically used. 29. A plasmid is opened by a restriction endonuclease into a rod with sticky ends. The foreign DNA is cleaved with the same restriction enzyme, giving another rod with complementary, sticky ends. By chance, some plasmids will circularize into plasmids once some, some of which will contain insertion of the foreign DNA. Bacterial cells are then transfected by the plasmids, and the colonies grown. Genes for two antibiotic resistance conferring genes are used, because the plasmid is typically opened with one resistance-conferring gene. If foreign DNA is inserted into that gene, progeny colonies will lose their resistance to that antibiotic. The other gene is used to determine whether bacteria carry the plasmids at all, whether or not they contain DNA for the foreign gene. Use of the two markers will allow colonies to be selected that carry the recombinant plasmid. Spring ‘09 24. Facilitated diffusion shows saturation when rate of transport is plotted as a function of concentration. Rate of passive diffusion is a linear function of concentration of the compound transported. 26. (a) H-BOND: A weak polar interaction between a hydrogen attached to an element with an unshared electron pair and anyther element with an unshared electron pair. (b) Parallel b-sheet: Polypeptide chain in fully-extended conformation having regular hydrogen bonds between peptide hydrogens and carbonyl oxygens. Regular secondary structure. Chains are oriented in the same directions. (c) Sucrose: A disaccharide consisting of a fructose joined to a glucose by a β 1->2 glycoside link. (d)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 11

EXAM REVIEW 1 - Spring 10 25. (4) Glutamine in its fully...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online