3. Energy & Cell Processes

Most of the CO2 from cellular respiration is released duringa. stage 1: glycolysis.b. stage 2: pyruvate oxidation.c. stage 2: the citric acid cycle.d. stage 3: oxidative phosphorylation.

Which of the following is the most immediate source of energy for making most of the ATP in your cells?a. the transfer of from intermediate substrates to ADPb. the movement of H+ across a membrane down its concentration gradientc. the splitting of glucose into two molecules of pyruvated. electrons moving through the electron transport chain

Most CO2 from catabolism is released duringa. glycolysis.b. the citric acid cycle.c. lactate fermentation.d. electron transport.

Most of the energy in an ATP molecule is released .a. during cellular respiration;b.when the terminal phosphate group is hydrolyzed;c. in the form of new nucleotides;d. when it is transferred to NADH

Which of the three stages of cellular respiration is considered the most ancient? Explain your answer.

Early estimates suggested that the oxidation of glucose via aerobic respiration would produce 38 ATP. Based on what you know of the theoretical yields of ATP from cellular respiration, show how this total was determined. Why do biologists now think this amount of ATP per molecule of glucose is not achieved in cells?

VISUAL SKILLS This computer model shows the four parts of ATP synthase, each part consisting of a number of polypeptide subunits (the structure in gray is still an area of active research). Using Figure 9.14 as a guide, label the rotor, stator, internal rod, and catalytic knob of this molecular motor.