Food and Nutrients Worksheet for 14-Year-Olds | English, PE & Science Comprehension and Q&A

Instructions

1. Read the informational text "Fueling the Human Engine" carefully.
2. Complete Section 1: Reading & Text Analysis using complete sentences and evidence from the text.
3. Complete Section 2: The Science of Digestion and Metabolism by analyzing how nutrients interact with body systems.
4. Complete Section 3: PE & Real-World Application to design an optimal nutritional plan for athletic performance.
5. Tackle the optional Challenge Level for advanced credit.
6. Check your work against the Answer Key provided at the back when finished.

Informational Reading Passage: Fueling the Human Engine

Imagine your body as a high-performance sports car. To keep it running efficiently, you cannot simply pour any fluid into the fuel tank. The human body requires a precise mixture of organic compounds to fuel physical movement, build tissue, and maintain metabolic equilibrium. Nutrition is not merely about satisfying hunger; it is the biochemical process by which an organism ingests, digests, absorbs, transports, and utilizes nutrients for cellular survival.

Nutrients are categorized into two major classes: macronutrients (required in large amounts) and micronutrients (required in trace amounts).

1. The Energy Providers: Carbohydrates, Lipids, and Proteins

• Carbohydrates are the body’s primary energy source. During digestion, complex carbohydrates (starches and fibers) are broken down into simple sugars, predominantly glucose. Glucose enters the bloodstream and travels to cells, where it undergoes cellular respiration—a metabolic process inside the mitochondria that converts glucose and oxygen into Adenosine Triphosphate (ATP), the fundamental energy currency of life. Excess glucose is stored in the liver and skeletal muscles as glycogen for rapid conversion during intense physical exercise.
• Lipids (Fats) provide long-term energy storage, protect vital organs, insulate the body, and form cell membranes. While carbohydrates power short-burst, high-intensity exertion, fats are oxidized to sustain low-to-moderate physical activity over extended durations.
• Proteins consist of long chains of amino acids. While they can be broken down for energy as a last resort, their vital role lies in tissue repair, enzyme production, and muscle synthesis. Following physical exercise, micro-tears in muscle fibers require amino acids to repair and strengthen the muscle tissue—a process known as hypertrophy.

2. The System Regulators: Micronutrients and Water

• Vitamins (organic compounds) and Minerals (inorganic elements) do not yield direct energy, but they act as essential catalysts. For instance, Iron is a critical component of hemoglobin, the protein in red blood cells that transports oxygen from the lungs to working muscles. A deficiency in iron leads to fatigue and impaired aerobic performance. Calcium and Vitamin D work synergistically to maintain bone density and regulate muscle contractions.
• Water accounts for roughly 60% of total body mass. It is the solvent for chemical reactions, regulates body temperature through sweat evaporation, and maintains blood volume required for cardiovascular efficiency during activity.

When food is consumed, mechanical digestion (chewing) and chemical digestion (enzymatic breakdown) reduce complex matrices into molecular units. These units pass through the microvilli of the small intestine into the circulatory system, delivering metabolic fuel directly to hardworking cells. Understanding this biochemical partnership between nutrition, physiology, and physical output allows individuals to optimize both daily health and athletic performance.

Section 1: English & Reading Comprehension

A. Vocabulary in Context
Define each term based on how it is used in the text, then write a original sentence applying the word to a physical education context.

1. Metabolic Equilibrium

   • Definition: ____
   • Original Sentence: ____

2. Cellular Respiration

   • Definition: ____
   • Original Sentence: ____

3. Synergistically

   • Definition: ____
   • Original Sentence: ____

B. Text-Based Short Answer Questions
Answer using complete sentences and specific textual evidence.

1. Explain the specific biological difference between how the body utilizes carbohydrates versus fats during physical activity.

   ---

   ---

2. According to the passage, why is protein not considered the body's primary energy choice, and what is its main function after physical exertion?

   ---

   ---

3. What central analogy does the author use in the introductory paragraph, and how effective is it in framing the topic of human nutrition?

   ---

   ---

Section 2: Science Focus - How Nutrients Work in the Body

Complete the graphic organizer below. Identify the main biological function of each nutrient, state a real-world food source, and explain how the body uses it during physical activity.

Section 3: Physical Education & Practical Application

Scenario: Maya is a 14-year-old high school track athlete who runs the 800-meter race. Recently, she has felt extremely exhausted halfway through her daily 2-hour practices, experiences muscle soreness that takes days to recover from, and occasionally feels dizzy in warm weather.

Analyze Maya's situation using your understanding of human nutrition and physiology. Answer the following diagnostic questions:

1. Energy Breakdown: Maya ate only a plain green salad with no dressing before practice. Explain biologically why she ran out of energy halfway through her training.

   ---

   ---

2. Recovery & Repair: Which nutrient is missing from Maya's post-workout routine that is causing prolonged muscle soreness? What specific physiological process is lacking?

   ---

   ---

3. Performance Meal Plan: Design a balanced Pre-Workout Meal (2-3 hours before practice) and a Post-Workout Recovery Snack (within 45 minutes after practice) for Maya.

   • Pre-Workout Meal:

     • Food Items: _____
     • Targeted Nutrient(s): ____
     • Biological Purpose: __

   • Post-Workout Recovery Snack:

     • Food Items: _____
     • Targeted Nutrient(s): ____
     • Biological Purpose: __

Section 4: Challenge / Extension (Optional)

Biochemical Synthesis: Write a short paragraph (4-6 sentences) explaining how the Digestive System, Circulatory System, and Muscular System work together to convert a piece of whole-wheat toast into a sprint across a soccer field. Use the following terms in your response: enzymes, microvilli, bloodstream, glucose, mitochondria, ATP.

Answer Key

Section 1: English & Reading Comprehension

A. Vocabulary in Context

1. Metabolic Equilibrium: A balanced state of internal chemical processes in the body. (Example sentence: Proper hydration helps athletes maintain metabolic equilibrium during long races.)
2. Cellular Respiration: The biochemical process by which cells convert glucose and oxygen into ATP energy. (Example sentence: Mitochondria perform cellular respiration to fuel muscle contractions during a sprint.)
3. Synergistically: Working together to produce a combined effect greater than the sum of their separate effects. (Example sentence: Calcium and Vitamin D work synergistically to build strong bones in growing teenagers.)

B. Text-Based Short Answer Questions

1. Carbohydrates are converted into glucose/glycogen for rapid, high-intensity energy production. Fats are oxidized for sustained, low-to-moderate intensity energy over longer durations.
2. Protein is reserved primarily for tissue repair, enzyme creation, and muscle growth/hypertrophy following exertion rather than immediate energy production.
3. The author compares the human body to a high-performance sports car. It is effective because it clearly illustrates that biological systems require high-quality, specialized fuel to function at peak efficiency.

Section 2: Science Focus - Graphic Organizer

• Lipids (Fats): Long-term energy storage, insulation, cell membrane production | Avocados, nuts, olive oil, salmon | Sustained energy fuel for low-to-moderate long-duration activity.
• Proteins: Muscle repair, tissue synthesis, enzyme production | Chicken breast, eggs, beans, tofu | Rebuilds micro-tears in muscle tissue post-exercise (hypertrophy).
• Iron (Mineral): Oxygen transport in blood via hemoglobin | Spinach, red meat, lentils | Delivers oxygen to working muscles to prevent fatigue during aerobic exercise.
• Calcium (Mineral): Bone strength, cellular signaling, muscle contraction | Milk, yogurt, fortified plant milk, leafy greens | Enables proper skeletal muscle contractions and maintains structural bone density.
• Water: Temperature regulation, nutrient transport, solvent for biochemical reactions | Water, cucumbers, watermelon | Regulates body temp via sweating and maintains blood volume for heart health.

Section 3: Physical Education & Practical Application

1. A green salad lacks carbohydrates. Without complex carbs, her body had no glucose to replenish glycogen stores, leaving her mitochondria without fuel for cellular respiration.
2. Protein is missing. Post-workout muscle repair requires amino acids to repair micro-tears in muscle fibers (muscle hypertrophy).
3. Pre-Workout: Whole-grain bagel with peanut butter and banana. Nutrients: Complex carbs & healthy fats. Purpose: Sustained glucose release for practice energy.
   Post-Workout: Chocolate milk or Greek yogurt with berries. Nutrients: Fast-acting carbohydrates & high-quality protein. Purpose: Replenish glycogen and provide amino acids for muscle repair.

Section 4: Challenge / Extension

Sample Answer: When whole-wheat toast is eaten, enzymes in the Digestive System break down complex starches into simple glucose molecules. These molecules pass through the microvilli of the small intestine and enter the bloodstream of the Circulatory System. The circulatory system transports the glucose along with oxygen to active cells in the Muscular System. Inside the muscle cells' mitochondria, glucose undergoes cellular respiration to produce ATP, which supplies the direct mechanical energy required to sprint across the soccer field.