During this procedure, we will run three types of trials: room temperature enzyme, heated enzyme, and frozen enzyme. Based on what you know about enzymes which of the following
possible hypothesis statements makes the most sense?
If room temperature is the enzyme's optimum, then we should expect less oxygen bubbles in the heated and
frozen enzymes.
If we observe the most oxygen bubbles coming from the frozen enzyme, then its optimum temperature is
when it is heated.
If we apply oxygen to the enzyme at all three temperatures, then we should expect hydrogen peroxide to be
produced in each trial.

On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.