4.10: Applied Thinking Self - Assessment

Writing Guidelines

• Answer each question in your own words.
• Write 4–8 clear, complete sentences per question, organized into short paragraphs (not bullet points).
• Focus on explaining your reasoning, not just stating the answer.
• Use correct scientific vocabulary, and briefly define terms when needed.
• For questions that ask you to compare, contrast, or explain why/how:
  • Clearly state similarities or differences
  • Support your ideas with a brief explanation or example

From Digestion to ATP: Fate of a Glucose Molecule

1. Trace the path of a single glucose molecule from digestion in the GI tract to ATP production in a cell under aerobic conditions.
2. Identify where major oxidation–reduction (redox) reactions occur (glycolysis, pyruvate oxidation, citric acid cycle, electron transport chain).
3. Explain how NADH and FADH₂ are generated and how they contribute to ATP synthesis.
4. Explain why the presence of oxygen dramatically increases ATP yield compared with anaerobic glycolysis alone.

Insulin and Glucose Uptake: Maintaining a Concentration Gradient

1. Insulin is released when food is ingested and stimulates the uptake of glucose into cells.
2. Describe the mechanisms cells use to maintain a concentration gradient that allows continuous glucose uptake from the bloodstream (include glucose transporters, phosphorylation of glucose inside the cell, and how this prevents back‑diffusion).

Conversion of Carbohydrates to Fat

1. Discuss how excess dietary carbohydrates can be converted into and stored as fat.
   1. Include the major metabolic pathways (e.g., glycolysis, acetyl‑CoA formation, fatty acid and triglyceride synthesis) and where they occur in the body.

Diabetes and “Alcohol‑Smelling” Breath

1. A person with diabetes has breath that smells like alcohol or nail polish remover.
   1. Explain what this odor most likely indicates, the underlying metabolic changes, and why this situation can be dangerous.

Protection Against Self‑Digestion by Pancreatic Enzymes

1. Trypsin and chymotrypsin, if released in their active forms, could digest pancreatic or intestinal tissues. Describe the mechanisms the body uses to prevent self‑digestion (include zymogen secretion, activating enzymes, and inhibitors, and where activation occurs).

Type II Diabetes and “Starving in a Sea of Plenty”

1. In type II diabetes, insulin is produced but is ineffective at stimulating normal glucose uptake.
   1. Explain why patients are described as “starving in a sea of plenty,” even though their blood glucose levels are high.
   2. Describe how impaired cellular glucose uptake leads to malnutrition at the cellular and tissue level.

Synthesis of Ketone Bodies

1. Ketone bodies can be used as an alternative fuel during fasting or starvation.
   1. Describe where and how ketone bodies are synthesized, including the role of fatty acid oxidation and acetyl‑CoA.
   2. Briefly explain how ketones are used by other tissues.

Shivering, Non‑Shivering Thermogenesis, and Metabolism

1. On a cold day, a lightly dressed person begins to shiver.
   1. Explain how shivering and non‑shivering thermogenesis both increase metabolic rate and energy expenditure.
   2. Discuss the role of the hypothalamus in temperature regulation and the main heat‑exchange mechanisms (e.g., radiation, convection, conduction, evaporation).
2. Predict how prolonged exposure to cold might change basal metabolic rate and the types of fuels used.
   1. Explain how vasoconstriction helps increase or preserve core body temperature.

“Non‑Fat” Foods and Weight Gain

1. Many “low‑fat” or “non‑fat” products contain large amounts of added sugar.
   1. Discuss how high sugar intake from these foods can still lead to increased body fat and weight gain.
   2. Include the concepts of energy balance, insulin response, and conversion of excess carbohydrate to fat.

Vitamins and Minerals in Metabolism

1. Choose two vitamins and two minerals that play key roles in metabolic pathways (for example, B‑complex vitamins, vitamin C, iron, magnesium, iodine). For each nutrient:
   1. Describe its role as a cofactor, coenzyme, or structural component in metabolism.
   2. Explain how a deficiency would disrupt specific metabolic reactions.
   3. Provide at least one example of clinical symptoms or conditions that might result.

Designing a One‑Day Eating Pattern for Metabolic Health

1. Using your understanding of macronutrient metabolism, energy balance, and nutrient quality, design a one‑day eating pattern for a sedentary adult aimed at supporting metabolic health and preventing diet‑related disease. Include:
   1. Approximate macronutrient distribution (percent of calories from carbohydrates, fats, and proteins).
   2. Example meals and snacks (with a brief description of foods).
   3. Rationale for meal timing (e.g., spacing of meals, handling of evening eating).
   4. Justification for including or limiting certain foods or nutrients (e.g., fiber, added sugars, saturated fats, whole vs. refined grains).
2. Explain how your plan helps prevent or manage conditions such as obesity, type II diabetes, dyslipidemia, and cardiovascular disease.

Glycogen Storage and Mobilization

1. Describe how glycogen is synthesized (glycogenesis) and broken down (glycogenolysis) in liver and muscle.
   1. Explain how these processes help maintain blood glucose and provide energy during exercise.

Basal Metabolic Rate vs. Total Energy Expenditure

1. Define basal metabolic rate (BMR) and total daily energy expenditure (TDEE).
2. Identify the main factors that influence each (e.g., age, sex, body composition, hormones, activity level) and explain how they interact in weight gain or loss.

Metabolic Flexibility

1. Explain the concept of metabolic flexibility (the ability to switch between carbohydrate and fat oxidation).
2. Discuss how diet, physical activity, and insulin sensitivity affect metabolic flexibility and why it is important for long‑term health.