GRE Subject Question

Matching Nightmare Questions A) Secondary B) Tertiary C) Super-secondary D) Domain I) Final three-dimensional packaging of all three regions of a single polypeptide chain II) Packing together of two or more adjacent folded sections within a contiguous piece of polypeptidechain (found to occur in many unrela ...continues

interpreting helical wheel projections (alpha helices)

Shows how to interperet a helical projection of an alpha helix: predicting external vs internal side, and determining the amino acid sequence

peptide sequencing

Deducing a peptide sequence from enzymatic and chemical cleavage

re-folding experiments on insulin and pro-insulin

Explains why pro-insulin can be refolded but not insulin (following Anifansen's experiments with ribonuclease)

GRE (Biochem) Subject Question

A major difficulty in investigating the properties of pancreatic serine proteases is that these enzymes, being proteins, are self digesting. The problem however , is less severe for solutions of chymotrypsinthan for solutions of elastase or trypsin. Suggest an explantion for this observation? (Do not consider the zymogen ...continues

GRE (Biochem) Subject Question

When quantifying the activity of an enzyme, does it matter wheter you measure the appearence of a product or the dissapearence of a reactant? Please explain this to me. . . .

GRE Biochem Subject

It is possible to distinguish between irreversible inhibitor and a classical mixed type reversible inhibitor by measuring Vmax of the enzymatic reaction as a function of [E]total in the absence and presence of the inhibitor. What does the slope represent in each case? What does the X-axis intercept represent in each case? ...continues

GRE subject Biochem

How many different possible disaccharides can be formed between the pyranose forms od D-galactose and D-glucose? How many are nonreducing? Please explain or show the reasoning on this question .. .. .

GRE subject Biochem

Discuss the feasibility of using methylation analysis to distinguish between each of the following pairs of carbohydrates: A) Maltose and Trehalose B) Maltose and Amylose C) Amylose and Cellulose Please explain this . . .

Changes in pyridoxal phosphate structure on catalysis

2. Pyridoxal phosphate is required for transamination reactions. The mechanism of catalysis by pyridoxal phosphate can be studied free of enzyme, since pyridoxal itself (shown in attachment) is active towards substrates in the presence of a metal ion (the rate is significantly reduced, but can be measured). Consequently, one ...continues