1) Describe the alternative fates of pyruvate in cellular respiration.
2) Write notes on the structure and significance of α and β glycosidic bonds.
3) Describe the mechanism of DNA duplication. Include a brief account of the types of proteins, cofactors and enzymes involved.
4) Write an account of two of the key historical experiments that identified DNA as the carrier of the genetic code.
5) Describe the “central dogma” for the genetic code and the basis by which genetic information in a chromosomal gene is converted into a globular protein.
6) Describe, using specific examples where appropriate, the four different levels of protein structure, describing the roles of amino acids in determining these structures.
7) The glycolytic intermediate, Fructose 1,6, Bisphosphate (FBP) can be assayed by a series of coupled enzymic reactions;
FBP —> GAP + DHAP (aldolase)
GAP —> DHAP (Triose phosphate isomerise)
2DHAP + 2NADH + 2H+ —> 2 G-3-P + 2NAD+ (glycerophosphate dehydrogenase)
When 20μl of a solution containing FBP was added to a cuvette, containing the required substrates and enzymes in excess, to give a total volume of 1ml., the absorbance at 340nm dropped from 2.5 to 0.6 absorbance units. You can assume all reactions proceed to completion.
Given that the molar absorptivity constant at 340nm for NADH is 6220 L.mol-1, calculate the millimolar concentration of the original FBP solution.
Note. you will be given credit for partially correct calculations.
8) Write notes on substrate level and oxidative phosphorylation, giving suitable examples.
9) Write notes on the relationship between the structure, properties and functions of glycogen and cellulose.
10) Write notes on the 3 main types of column chromatography (not HPLC), explaining their mode of action and principal uses.
11) Write notes on TWO of the following chromatographic techniques: Thin layer chromatography, gel (size exclusion) chromatography, ion exchange