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In the citric acid cycle, citrate is formed with six carbon atoms: four from oxaloacetate (from the citric acid cycle) and two from acetyl CoA.  At the end of this cycle (just before citrate synthase), oxaloacetate is formed again.  Of the four carbon atoms in oxaloacetate, are from acetyl CoA and are from the original oxaloacetate atom.  The rest of the carbon atoms are transferred into .

What type of enzyme catalyzes the first step of the citric acid cycle (citrate synthase)?

The biochemistry lab class was given some trypsinogen that is synthesized in vitro using cell lysates containing all components necessary for transcription and translation. When they ran the enzyme activity assay, they found the enzyme does not exhibit any protease activity.  Why?

Consider the structure of ATP synthase:

In a few sentences, describe what you have learned about protein folding in this course. Questions to address in your response (address at least 3-4): How does protein folding occur? What determines the shape of a protein? How many folded shapes do most proteins form? What is the relationship between protein folding and activity? What happens to mis-folded proteins?

Control of pyruvate oxidation: The pyruvate dehydrogenase complex is regulated in more than one way. Describe two different ways (mechanisms) by which this complex can be regulated. For each one, name the type of regulation/control, describe how the regulation is mediated, and include a brief rationale.

This question is about the specificity of serine proteases such as chymotrypsin.  I want to design a mutant so that it would selectively cleave a protein at the peptide bond right after glycine.  Explain how you would alter the protein and justify your answer.  In your answer, (a) specify the part of the protein that you would modify and (b) what type of residue(s) you would put there (description is required; specific design is not). Then, justify your answer by describing how that will accomplish the desired goal.

General Chemistry Lab II – Level 2 Which of the following statements is false?

General Chemistry Lab II – Level 1 Which equation would be most helpful for determining the heat released when a metal sample is placed in a calorimeter?

Level 1 – K and ΔG Which of the following is correct regarding Gibbs Free Energy (Δ G) and Equilibira (K)?