Nutrition Chapter A&P Test 2

What is nutrition, and why is it important for the body?

Nutrition is the study of nutrients and how the body uses them. It is essential for energy production, growth, and maintenance of body functions.

What are nutrients, and how do they support metabolic processes?

Nutrients are chemicals from the environment that organisms need for survival. They provide energy, aid in growth, and support body functions.

What are the two major classes of nutrients, and how do they differ?

Macronutrients (carbohydrates, lipids, proteins) are needed in large amounts for energy, while micronutrients (vitamins, minerals) are needed in small amounts for metabolism.

What are essential nutrients, and why must they be obtained from the diet?

Essential nutrients are substances the body cannot synthesize in sufficient amounts, so they must come from food.

What are calories, and how do they measure energy in food?

Calories are units of heat that measure the amount of energy food provides.

What are carbohydrates, and what role do they play in the body?

Carbohydrates are organic compounds that provide energy for cellular processes.

What are the different sources of carbohydrates in the diet?

Sources include plant-based foods (starch, fiber), dairy (lactose), and fruits (fructose, glucose).

What are polysaccharides, and where are they found?

Polysaccharides are complex carbohydrates found in plant starch and animal glycogen.

How do disaccharides and monosaccharides differ, and what are their sources?

Disaccharides (double sugars) come from dairy and cane sugar, while monosaccharides (single sugars) come from fruits and honey.

What is cellulose, and why is it important even though it is not digested?

Cellulose is a complex carbohydrate that provides dietary fiber, aiding digestion.

How are carbohydrates broken down and absorbed in the digestive system?

Carbohydrates are broken down into monosaccharides and absorbed into the bloodstream.

Why is glucose considered the main fuel for cellular respiration?

Glucose is the primary energy source for ATP production in cells.

What happens to excess glucose in the body?

Excess glucose is stored as glycogen in the liver and muscles or converted to fat.

What is glycogenesis, and how does it function in glucose storage?

Glycogenesis is the process where excess glucose is stored as glycogen.

What is lipogenesis, and how does excess glucose contribute to fat storage?

Lipogenesis converts excess glucose into fat for long-term storage in adipose tissue.

What is gluconeogenesis, and when does the body use this process?

Gluconeogenesis is the formation of glucose from non-carbohydrate sources, used when glucose levels are low.

What is the primary function of carbohydrates in energy production?

Carbohydrates provide the main source of energy for body functions.

How does individual energy requirement affect carbohydrate intake?

People with higher energy needs require more carbohydrates.

What is the estimated daily carbohydrate intake needed for the human diet?

An intake of at least 125-175 grams per day is recommended.

How does the average carbohydrate intake in the U.S. compare to the recommended levels?

Most people consume 200-300 grams per day, which is higher than the estimated minimum requirement.

What are lipids, and what are their main functions in the body?

Lipids are organic compounds that store energy, insulate the body, and form cell membranes.

What are the different types of lipids found in food?

Lipids include triglycerides, phospholipids, and cholesterol.

What are triglycerides, and why are they the most common dietary lipid?

Triglycerides are fats and oils composed of glycerol and fatty acids; they are the main source of stored energy.

What are saturated fats, and what are their common dietary sources?

Saturated fats come from animal products like meat, eggs, and dairy.

How do unsaturated fats differ from saturated fats?

Unsaturated fats have double bonds between carbon atoms and are found in plant-based oils.

What foods contain monounsaturated fats, and why are they considered the healthiest?

Avocados, nuts, and olive oil contain monounsaturated fats, which help lower bad cholesterol.

What are the main dietary sources of cholesterol?

Cholesterol is found in animal products like eggs, liver, and dairy.

Why is cholesterol not found in plant-based foods?

Cholesterol is only produced by animals, not plants.

How do lipids provide energy compared to carbohydrates and proteins?

Lipids provide more than twice the energy per gram compared to carbohydrates and proteins.

What happens to triglycerides when they are broken down for energy?

They are broken into glycerol and fatty acids, which are used for energy.

How does the liver contribute to lipid metabolism?

The liver regulates cholesterol and produces lipoproteins for fat transport.

What are lipoproteins, and what are their functions in the body?

Lipoproteins transport fats in the bloodstream.

What are the different types of lipoproteins, and how do they differ in composition?

VLDLs (very low density) have high triglycerides, LDLs (low density) have high cholesterol, and HDLs (high density) have high protein.

How does the liver regulate cholesterol levels in the body?

It synthesizes, breaks down, and excretes cholesterol.

What role does adipose tissue play in lipid storage and release?

Adipose tissue stores excess lipids and releases them when needed for energy.

How does dietary fat intake affect health and disease risk?

Excessive fat intake increases heart disease risk.

What is the recommended percentage of dietary calories that should come from fats?

The American Heart Association recommends less than 30% of daily calories from fat.

Why is fat intake important for the absorption of fat-soluble vitamins?

Fat is required to absorb vitamins A, D, E, and K.

What are proteins, and what are their primary functions in the body?

Proteins are chains of amino acids essential for building and repairing tissues.

What happens to proteins during digestion and metabolism?

Proteins are broken down into amino acids, which are used for various functions or energy.

What is deamination, and why is it necessary for amino acid metabolism?

Deamination removes amino groups, allowing amino acids to be used for energy.

How can excess amino acids be converted into glucose or fats?

Through gluconeogenesis and lipogenesis, excess amino acids are repurposed.

What are some common dietary sources of protein?

Meats, dairy, nuts, eggs, and legumes.

How many amino acids does the body need, and how many are essential?

The body needs 20 amino acids; 8 are essential and must come from the diet.

What are complete and incomplete proteins, and how do they differ?

Complete proteins contain all essential amino acids (e.g., meat, eggs), while incomplete proteins lack some essential amino acids (e.g., plants).

What is nitrogen balance, and why is it important for protein metabolism?

Nitrogen balance reflects the balance between nitrogen intake and excretion.

What is positive nitrogen balance, and when does it occur?

It occurs when nitrogen intake exceeds excretion, such as during growth or pregnancy.

What is negative nitrogen balance, and what can cause it?

It occurs when nitrogen loss exceeds intake, often due to malnutrition or illness.

How much protein should an average person consume daily?

About 10-35% of daily calories, or 0.8 g per kg of body weight.

What are the consequences of protein deficiency in the diet?

Protein deficiency can cause muscle loss, immune dysfunction, and growth retardation.

How do carbohydrates, fats, and proteins contribute to energy production?

They provide calories that fuel metabolic processes.

What is the basal metabolic rate (BMR), and how does it relate to energy use?

BMR is the energy required to maintain basic body functions while at rest.

What factors influence a person’s BMR?

Gender, body size, body temperature, and thyroid hormone levels.

What is energy balance, and how does it affect body weight?

Energy balance occurs when calorie intake equals energy expenditure.

What is the difference between positive and negative energy balance?

Positive energy balance leads to weight gain, while negative energy balance leads to weight loss.

How is Body Mass Index (BMI) calculated, and what does it measure?

BMI is weight (kg) divided by height (m²) and assesses body fat levels.

What BMI ranges classify a person as underweight, normal weight, overweight, or obese?

Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (30+).

What are the health risks associated with obesity?

Increased risk of heart disease, diabetes, stroke, and certain cancers.

What factors regulate appetite and hunger in the body?

Hormones and neurotransmitters like leptin, ghrelin, insulin, and neuropeptide Y.

What hormones and neurotransmitters influence appetite regulation?

Leptin (decreases hunger), ghrelin (increases hunger), insulin, and neuropeptide Y.

How does leptin suppress appetite, and where is it produced?

Leptin is produced by fat cells and signals the brain to reduce food intake.

How does ghrelin stimulate hunger, and where is it produced?

Ghrelin is produced in the stomach and signals hunger to the brain.

What is the role of insulin in appetite control?

Insulin regulates blood sugar and signals satiety after eating.

What are vitamins, and why are they essential for metabolic processes?

Vitamins are organic compounds needed in small amounts for metabolism.

What is the difference between fat-soluble and water-soluble vitamins?

Fat-soluble vitamins (A, D, E, K) are stored in fat; water-soluble vitamins (B, C) are not stored and must be consumed regularly.

What are the functions of vitamin A, and what happens in case of deficiency?

Vitamin A supports vision and immune function; deficiency leads to night blindness.

How does vitamin D contribute to bone health?

Vitamin D aids calcium absorption for strong bones.

What is the role of vitamin K in blood clotting?

Vitamin K is required for the synthesis of clotting factors.

What are B vitamins, and why are they grouped as a vitamin complex?

B vitamins support energy metabolism and cell function and are often found in the same foods.

What is vitamin C's role in collagen formation and immunity?

Vitamin C helps produce collagen, supports the immune system, and enhances iron absorption.

What are minerals, and how do they differ from vitamins?

Minerals are inorganic elements needed for metabolic functions.

What are the major minerals required by the body?

Calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium.

How do calcium and phosphorus contribute to bone structure?

They are primary components of bones and teeth.

What are trace elements, and why are they needed in small amounts?

Trace elements like iron, zinc, and iodine are essential for enzyme function and health.

What is the function of iron in the body?

Iron is a key component of hemoglobin, which carries oxygen in the blood.

How does iodine contribute to thyroid hormone production?

Iodine is necessary for the synthesis of thyroid hormones that regulate metabolism.

What is the role of zinc in immune function and wound healing?

Zinc supports immune responses and cell repair.

What are the key principles of a healthy diet?

A balanced intake of macronutrients, vitamins, and minerals.

How does the MyPlate model help with balanced eating?

It provides guidelines for portion sizes of food groups.

What are the different types of vegetarian diets, and what foods do they include?

Vegan (no animal products), lacto-vegetarian (dairy allowed), ovo-vegetarian (eggs allowed), and pesco-vegetarian (fish allowed).

How can vegetarians ensure they get enough essential nutrients?

By combining plant proteins and consuming fortified foods or supplements.

What is malnutrition, and what are its main causes?

Malnutrition is poor nutrition due to insufficient or excessive intake of nutrients.

What is the difference between undernutrition and overnutrition?

Undernutrition is a deficiency of essential nutrients, while overnutrition is excessive nutrient intake leading to obesity.

What is primary malnutrition, and how does it differ from secondary malnutrition?

Primary malnutrition results from poor diet alone; secondary malnutrition occurs when the body cannot absorb or use nutrients properly.

What are common symptoms of starvation?

Low blood pressure, slow pulse, chills, dry skin, and poor immunity.

What are marasmus and kwashiorkor, and how do they differ?

Marasmus is caused by overall calorie deficiency; kwashiorkor is caused by protein deficiency.

What are the long-term effects of starvation on the body?

Muscle wasting, organ damage, immune suppression, and death.

How do nutritional needs change over a person’s lifetime?

Nutritional needs vary based on age, activity level, and health status.

What are common dietary concerns in aging adults?

Reduced appetite, difficulty chewing, and vitamin D or calcium deficiencies.

How does basal metabolic rate change with age?

BMR decreases with age, leading to lower energy needs.

How does calcium and vitamin D deficiency affect older adults?

It increases the risk of osteoporosis and bone fractures.