Addition of electron(s) to a substance is the process of (1). Removal of electron(s) from a substance is the process of (2). In terms of moving the electrons from one substance to another, electron carriers that are (3) or are (4) can be employed. Bacteria can have electrons move along the (5) membrane. (6) move each electron to stronger and stronger electron acceptors in the membrane. Ultimately, the electron will be added to (7) to generate water. Meanwhile, the protons generated during all this electron transfer are transported back across the membrane to form (8).

Describe how cells obtain their energy to do work via ATP. Start with the carbohydrates eaten in a meal and has 3 major steps. For each step write where the step occurs, what molecules go in to each step, what molecules come out of each step, and if each step is areobic or anaerobic?

Set-up: A cell is able to extract energy from the molecule glucose after it breaks it's C-C and C-H bonds and replaces them with C=O and O-H bonds in CO2 and H20 in order to power unfavorable reactions. Questions: In a few brief sentences describe why cells can gain energy from this process. A successful answer should include the following: 1. How the action of breaking bonds relates to energy 2. How forming bonds relates to energy 3. Why some of these bonds store more energy to others

Drugs are small molecules that often occur in either a neutral or a charged form, depending on pH. For example, aspirin can be either neutral or lose a proton to be negatively charged. When aspirin is charged, it does not diffuse well into the body. pH varies in the gastrointestinal track. Since the stomach has a low pH (pH=3), it has a larger concentration of neutral aspirin (10-3 M), while the small intestine (pH=6) has a smaller neutral aspirin concentration (10-6 M). For the following, assume that the neutrally charged aspirin molecule has a diffusion coefficient through the cell of 1 x 10-6 cm2/s.  C) We’d like to figure out where in the body aspirin is absorbed as determined by its diffusion rate. If the small intestine has a surface area 50 times that of the stomach, what is the ratio of the diffusion rates in the stomach compared to the small intestine?   D) In which part of the GI tract is most of the aspirin absorbed?