Explain why they change shape, the effect this has on the reaction they catalyze, and why the change in shape causes this effect.

In very high pH, enzymes (which are proteins) often unfold and change their shape. Explain why they change shape, the effect this has on the reaction they catalyze, and why the change in shape causes this effect.
You are taking an in-class exam. The professor knocks over their chair during the exam, startling you. You look up and realize what happened, but it takes a little while before you can fully return to focusing on the exam after the scare. Explain what happened in your body immediately, and why it took you a while to calm down. Include the hormones involved and where they came from. What was going on in your endocrine system before the chair dropped, due to longer term stress about your exam? Do you think this affected your response to the chair?