Describe what information can be inferred from the positive-inside rule. (5 Marks) 3.2 Describe how the hydropathy index is calculated and how it is used to infer the structure of membrane proteins. (5 Marks) 3.3 Discuss what is the likely three dimensional structure of the protein analyzed in the hydropathy index graph shown in Figure 1. (7.5 Marks) 1.2 0.8 0.4 Hydropathy Index 0.0 -0.4 -0.8 1 100 200 300 400 500 600 Residue Figure 1 adapted from FEMS Microbiology Reviews, Volume 22, Issue 4, October 1998, Pages 305-322 Explain the general mechanism that allows enzymes to accelerate the rate of reactions. (5 Marks) 4.2 What equation describes the velocity of a zero order enzymatic reaction? (2.5 Marks) Provide the units of the rate constant. (2.5 Marks) 4.3 Discuss, including the mathematical description, when the Km of an enzyme approximates to the affinity constant of its substrate. (5 Marks) 4.4 How can you assess experimentally whether an enzymatic reaction has reached the steady-state? (2.5 Marks) Question 5 5.1 Describe in detail the full process of activation of chymotrypsin zymogen. (10 Marks) 5.2 Suggest with rationale two different mutations that would render chymotrypsinogen non-activable. Each proposed mutation should underpin a different means of inactivation. (7.5 Marks) Question 6 6.1 Describe the mechanism by which ATP synthases convert into a mechanical force via the electrochemical gradient generated by the electron transport chain. (5 Marks) 6.2 Describe the mechanism by which complex IV of the electron transport chain contributes to the formation of an electrochemical gradient. (7.5 Marks) 6.3 Describe the function of the heme groups in the electron transport chain and how they contribute to the activity of the electron transport chain. (5 Marks) Question 7 7.1 What are analogues according to the evolution of proteins? How do analogues differentiate from a protein that functions as a molecular mimicry? (7 Marks) 7.2 What are the two main evidence that may support the notion that homology among proteins may indicate an ancestral relationship. (3.5 Marks) 7.3 Describe protein evolutionary divergence with an example.
