5. a. In the process of converting ADP to ATP, water is circle one: (REQUIRED / RELEASED) and therefore this is called a reaction type. Does this type of reaction require an enzyme? circle one: (NO/YES / sometimes) This reaction circle one: (REQUIRES / RELEASES) energy! b. In the process of converting ATP to ADP, water is circle one: (REQUIRED / RELEASED) and therefore this is called a reaction type. Does this type of reaction require an enzyme? circle one: (NO/YES / sometimes) This reaction circle one: (REQUIRES / RELEASES) energy! c. A given molecule of ATP can be broken down to ADP + P close to 1500 times in a day ("ATP cycle"). This is occurring in order to for cellular work. List a few examples of cellular work. d. Where does the energy to make ATP come from? It doesn't make sense to use ATP to make ATP. The energy to make ATP comes from specifically these types of macromolecules: and

1. A substrate is converted to product using an enzyme that follows the mechanism below when an inhibitor (1) and an activator (A) are both present in the reaction mixture. ES (2)→→ E + P E+S (1) E +1 < (3) → EI E+A← (4)→ EA {the inhibitor and activator do not bind simultaneously} EI + S EA+S (5) → EIS -(6)→ EI + P (7)→ EAS-(8)→ EA + P with reaction rate constants of k₁ and k.₁ (and so on) for each of the reactions: A. Although this mechanism does not match exactly any of the inhibitor mechanisms discussed in class, which type of inhibitor is this most like (competitive, uncompetitive or non-competitive)? B. Write the enzyme balance equation. C. Write the total rate of product, P, formation based on the kinetic rate constants and concentrations of intermediate species. D. Write each of the equations that result from applying the rapid equilibrium and quasi steady state assumptions. E. Knowing that I is an inhibitor and A is an activator, discuss the relative values of k₂, k6 and kg.

11. (ME.23) Given the pathway below, steps catalyzed by enzymes, are good candidates for regulation and compound negatively regulate enzyme 5. A. All steps with -AG; compound H B. Steps catalyzed by enzymes 2 and 5 only; compound C C. Steps catalyzed by enzymes 4 and 5 only; compound H D. Steps catalyzed by enzymes 2, 4, 5, 6 & 8; compound C E. Steps catalyzed by enzymes 2, 4, 5, & 8; compound H A is a good candidate to AG +0.1 enz7 AG AG AG H AG AG +1.1 -23.3 -0.7 -1.4 -16.7 enz1 enz2 enz3 AG enz4 enz5 -

Hydrogen peroxide (H2O2) is a toxic chemical (waste product) that is produced when our bodies break down amino acids and complete other important metabolic reactions. Catalase is an enzyme found in our livers that is responsible for the decomposition (break down) of hydrogen peroxide into the harmless compounds of water and oxygen. Due to the enzyme's action, the cells in our bodies are able to rid themselves of the harmful H2O2 waste product. Without the catalase enzyme, many of our cells would be damaged by the increased amount of H2O2. When the enzyme is working, oxygen gas bubbles will be released. The chemical reaction that occurs is the following: catalase 2H2O2 → 2H,O + O2 Students in biology class performed an experiment to test the activity of catalase at different pH levels. The diagram below represents the students’ results. I II III IV V bubbles of. oxygen gas piece of liver containing catalase Strongly Acidic Solution Weakly Acidic Solution Strongly Basic Solution Weakly…