Question

1. brenda ran a 5 km race. during the race, she began to breathe heavily, and some of her muscles began to burn. which of these explains why brenda felt a burning in her muscles during the race? a) the cells did not have enough oxygen, so they used fermentation as a source of energy. b) the cells did not have enough glucose, so they used fermentation as a source of energy. c) the cells had too much glucose, so they used aerobic respiration as a source of energy. d) the cells had too much carbon dioxide, so they used aerobic respiration as a source of energy. 4) the diagram shows a model of the conversion between atp and adp. which statement is supported by the model?

Explanation:

1. During intense exercise like a 5 - km race, the body's oxygen demand exceeds supply. Cells switch to fermentation. Lactic - acid fermentation in muscle cells produces lactic acid, causing the burning sensation.
2. For the ATP - ADP model, ATP has three phosphate groups and ADP has two. When energy is released, a phosphate group is removed from ATP to form ADP. When energy is added, a phosphate group is attached to ADP to form ATP.

Answer:

1. A. The cells did not have enough oxygen, so they used fermentation as a source of energy.
2. When energy is released, ATP is converted to ADP; when energy is added, ADP is converted to ATP.