CDN Nutritional Science & Dietetics — Questions and Answers
Question 1: What is the primary function of carbohydrates in the human body?
- To provide essential fatty acids
- To regulate body temperature
- To provide energy (Correct answer)
- To build muscle tissue
Correct answer: To provide energy
Carbohydrates are the body's primary and most readily available source of energy. They are broken down into glucose, which cells use to produce ATP, fueling all metabolic processes and physical activities. This makes them essential for daily bodily functions.
Question 2: Which of the following is a function of proteins in the body?
- Providing energy only
- Supporting enzyme and hormone production (Correct answer)
- Only aiding in digestion
- Storing vitamins
Correct answer: Supporting enzyme and hormone production
Proteins are fundamental building blocks for a vast array of essential molecules in the body. They are crucial for synthesizing enzymes, which catalyze nearly all biochemical reactions, and many hormones, which regulate various physiological processes. Proteins also play vital roles in structural support, transport, and immune function.
Question 3: What role do vitamins play in metabolism?
- They provide energy directly
- They help enzymes perform metabolic functions (Correct answer)
- They store fat
- They only affect mood
Correct answer: They help enzymes perform metabolic functions
Vitamins do not provide energy directly but act as coenzymes or cofactors, assisting enzymes in performing their metabolic functions. They are crucial for facilitating biochemical reactions involved in energy production, nutrient utilization, and overall cellular health. Without adequate vitamins, metabolic processes would be severely impaired.
Question 4: How do lipids contribute to metabolism?
- They are only a source of energy
- They store energy, form cell membranes, and produce hormones (Correct answer)
- They produce enzymes
- They are mainly used for muscle repair
Correct answer: They store energy, form cell membranes, and produce hormones
Lipids are vital for several metabolic functions, including serving as a concentrated, long-term energy storage. They are also integral components of cell membranes, providing structural integrity and regulating substance passage. Furthermore, lipids are precursors for the synthesis of essential hormones, such as steroid hormones.
Question 5: What is the role of water in metabolism?
- It does not affect metabolism
- It regulates body temperature and aids digestion (Correct answer)
- It only hydrates the skin
- It is used for muscle growth
Correct answer: It regulates body temperature and aids digestion
Water is indispensable for countless metabolic reactions, acting as a solvent and transport medium for nutrients and waste products throughout the body. It also plays a critical role in thermoregulation, helping to maintain a stable body temperature, and is essential for the proper digestion and absorption of food.
Question 6: Which metabolic pathway produces ATP in cells?
- Fermentation
- Cellular respiration (Correct answer)
- Photosynthesis
- Lactic acid production
Correct answer: Cellular respiration
Cellular respiration is the primary metabolic pathway by which cells break down glucose and other fuel molecules to produce adenosine triphosphate (ATP). ATP is the main energy currency of the cell, powering virtually all cellular activities, from muscle contraction to active transport.
Question 7: How does the body regulate blood sugar levels?
- By increasing glucose intake only
- By secreting insulin and glucagon to regulate levels (Correct answer)
- By increasing fat storage
- By decreasing metabolism
Correct answer: By secreting insulin and glucagon to regulate levels
The body maintains blood sugar homeostasis primarily through the hormones insulin and glucagon, secreted by the pancreas. Insulin lowers high blood sugar by promoting glucose uptake into cells, while glucagon raises low blood sugar by stimulating the liver to release stored glucose, ensuring stable energy supply.
Question 8: What is the purpose of fiber in digestion?
- To slow down digestion
- To regulate digestion and prevent constipation (Correct answer)
- To absorb fats
- To increase calorie absorption
Correct answer: To regulate digestion and prevent constipation
Dietary fiber, though not digestible by human enzymes, adds bulk to stool, which helps to regulate bowel movements and prevent constipation. It facilitates the smooth passage of waste through the digestive tract, contributing to overall gut health and regularity.
Question 9: Which macronutrient is the body's primary source of quick energy?
- Proteins
- Carbohydrates (Correct answer)
- Fats
- Vitamins
Correct answer: Carbohydrates
Carbohydrates are the body's most readily available and preferred source of quick energy. They are rapidly broken down into glucose, which cells use immediately for fuel, making them ideal for meeting immediate energy demands during physical activity and daily functions.
CDN Nutritional Science & Dietetics
What is the primary function of carbohydrates in the human body?