Question

1. explain how a sprinter gets energy during a 30 second race. is the process aerobic or anaerobic? how does it compare to a long distance runner getting energy during a 5 - kilometer race?

1. how is a glucose changed during glycolysis?

1. how can mistakes made in this experiment be improved?

1. briefly compare the processes of cellular respiration in aerobic and anaerobic organisms. include the following: function of oxygen and the net gain of atp molecules.

Explanation:

Question 3

1. Sprinter (30 - second race):

• Energy source: The sprinter primarily uses stored ATP (adenosine triphosphate) and creatine phosphate initially. When these are depleted, anaerobic glycolysis (fermentation) occurs, breaking down glucose (from glycogen stores) without oxygen to produce ATP quickly. This process is anaerobic because the intense, short - duration effort outpaces oxygen delivery to muscles.
• By - product: Lactic acid is produced, which causes muscle fatigue.

1. Long - distance runner (5 - kilometer race):

• Energy source: For a 5 - km race (longer duration, lower intensity), the runner relies on aerobic respiration. Oxygen is available to muscle cells, so glucose (and fat) is broken down completely in the presence of oxygen (via glycolysis, Krebs cycle, and electron transport chain) to produce large amounts of ATP. This process is aerobic.
• Comparison: The sprinter’s energy is anaerobic (fast, limited ATP, lactic acid), while the long - distance runner’s is aerobic (slower, more ATP, no lactic acid buildup in the short term).

During glycolysis, a molecule of glucose (a 6 - carbon sugar, \(C_6H_{12}O_6\)) undergoes the following changes:

1. Phosphorylation: Glucose is phosphorylated (gains phosphate groups) using ATP, forming fructose - 1, 6 - bisphosphate.
2. Splitting: Fructose - 1, 6 - bisphosphate splits into two 3 - carbon molecules (glyceraldehyde - 3 - phosphate, or G3P).
3. Oxidation & ATP Production: G3P is oxidized (loses electrons), and phosphate groups are added. Eventually, each G3P is converted to pyruvate (a 3 - carbon molecule). In the process, a net of 2 ATP molecules are produced (2 ATP are used initially, 4 are generated) and 2 NADH (electron carriers) are formed.

In summary, glucose (6C) is split into two pyruvate (3C each) molecules, with a net gain of 2 ATP and 2 NADH.

Since the specific experiment is not provided, here are general strategies to improve experimental mistakes:

1. Replication: Repeat the experiment multiple times to reduce random error.
2. Control Variables: Ensure all variables (except the independent variable) are controlled (e.g., temperature, concentration, time).
3. Calibration: Calibrate equipment (e.g., pH meters, pipettes) to ensure accurate measurements.
4. Sample Size: Increase sample size to improve the reliability of results (e.g., test more organisms, use more trials).
5. Procedure Clarity: Refine the experimental procedure to eliminate ambiguity (e.g., precise timing, clear mixing instructions).

If the experiment involved cellular respiration (e.g., measuring gas exchange, enzyme activity), specific improvements could include:

• Ensuring airtight containers for gas measurements.
• Using fresh reagents (e.g., glucose, enzymes) to avoid degradation.

Answer:

• Sprinter (30s race): Uses stored ATP/CP first, then anaerobic glycolysis (anaerobic) to break down glucose for quick ATP (lactic acid by - product).
• Long - distance runner (5km race): Uses aerobic respiration (aerobic) to break down glucose/fat with oxygen for sustained, large - scale ATP production.

Question 4