essay

Three eating disorders and a major characteristic of each

Anorexia nervosa: self-starvation and severe restriction of food intake driven by an intense fear of gaining weight and a distorted body image, leading to dangerously low body weight.

Bulimia nervosa: recurring cycles of binge eating followed by compensatory purging behaviors such as self-induced vomiting, laxative use, or excessive exercise. Body weight is often in the normal range, which makes it harder to detect.

Binge eating disorder: recurrent episodes of eating unusually large amounts of food with a sense of loss of control, but without the regular compensatory purging seen in bulimia. It commonly leads to overweight or obesity.

Consequences of alcoholism (three medical, two social)

Medical conditions:

• Liver disease. Chronic heavy drinking causes fatty liver, then alcoholic hepatitis, and eventually cirrhosis (irreversible scarring that impairs liver function).

• Nutrient deficiencies. Alcohol displaces nutritious food and impairs absorption and metabolism of nutrients, especially thiamin (B1). Severe thiamin deficiency can cause Wernicke-Korsakoff syndrome, a form of brain damage.

• Increased cancer risk and cardiovascular damage. Alcohol raises the risk of cancers of the mouth, esophagus, and liver, and heavy use can lead to high blood pressure and heart muscle damage (cardiomyopathy).

Social conditions:

• Damaged relationships and family breakdown. Alcoholism strains marriages, parenting, and friendships, and is associated with domestic conflict and neglect.

• Loss of employment and financial or legal trouble. Impaired performance, absenteeism, DUIs, and accidents can lead to job loss, debt, and legal consequences.

Three main factors that determine how we age (with examples)

Genetics: the traits and predispositions you inherit. Example: a family history of longevity, or an inherited tendency toward high cholesterol or certain diseases.

Environment: external exposures and living conditions. Example: sun (UV) exposure accelerating skin aging, or exposure to pollution and toxins.

Lifestyle/behavior: the daily choices within your control. Example: eating a nutrient-dense diet, exercising regularly, not smoking, and managing stress can slow aging, while poor diet and inactivity speed it up.

 Best ways of addressing overweight and obesity in children

Focus on healthy habits rather than dieting or restriction, since children are still growing and need adequate nutrients. Effective approaches include improving diet quality (more fruits, vegetables, whole grains, and water; fewer sugar-sweetened beverages and highly processed snacks), increasing physical activity and reducing sedentary screen time, and involving the whole family so healthy eating and activity become the household norm rather than singling out the child. Parents modeling good behavior, keeping healthy foods available at home, ensuring adequate sleep, and letting the child "grow into" their weight as they get taller (instead of aiming for rapid weight loss) are all emphasized. Avoiding shaming and instead building a positive relationship with food helps prevent later eating disorders.

Four minerals and a function other than acting as a cofactor

Calcium: primary structural component of bones and teeth; also required for muscle contraction and nerve transmission.

Sodium: main extracellular electrolyte that regulates fluid balance and blood pressure.

Iron: central component of hemoglobin, which transports oxygen in the blood.

Iodine: essential for the synthesis of thyroid hormones, which regulate metabolic rate.

Five categories of protein functions with examples

Structure: proteins form the framework of tissues. Example: collagen in skin, tendons, and bone; keratin in hair and nails.

Enzymes: proteins that speed up chemical reactions without being consumed. Example: salivary amylase breaking down carbohydrates, or pepsin digesting protein.

Transport: proteins that carry substances through the blood or across membranes. Example: hemoglobin carrying oxygen, or lipoproteins carrying fats.

Hormones/regulation: proteins that act as chemical messengers and regulate body processes. Example: insulin regulating blood glucose.

Immune function: proteins that defend the body. Example: antibodies that identify and neutralize foreign pathogens or allergens.

(Two additional valid categories your textbook may include: fluid and acid-base balance, and providing energy when carbohydrate and fat are insufficient.)

Three types of nutrition studies (method, pros, cons)

Epidemiological (observational) studies: researchers observe large populations and look for associations between diet and health outcomes without intervening. Pros: can study large groups over long periods and generate hypotheses. Cons: they can only show correlation, not cause and effect, and are vulnerable to confounding variables.

Clinical trials (experimental/intervention studies): researchers deliberately alter one variable (for example, a diet or supplement) in participants and compare results against a control group, ideally with randomization and a placebo. Pros: can establish cause and effect and are well controlled. Cons: expensive, time-consuming, can raise ethical limits on what you can test in humans, and results may not always generalize.

Animal (laboratory) studies: experiments conducted on animals such as rats or mice. Pros: allow tight control of conditions and testing of things that would be unethical in humans, and are relatively fast and inexpensive. Cons: results do not always translate to humans because of physiological differences.

ATP: definition and how it is produced

ATP (adenosine triphosphate) is the body's main energy-carrying molecule; energy is stored in the bonds between its phosphate groups and released when a phosphate is broken off. It is produced primarily from the breakdown of energy-yielding nutrients, mainly glucose (and also fatty acids and amino acids). Aerobic production requires oxygen and takes place largely in the mitochondria of the cell, where glucose is fully broken down through glycolysis, the citric acid (Krebs) cycle, and the electron transport chain to yield a large amount of ATP. Anaerobic production (glycolysis without oxygen) occurs in the cytoplasm and yields only a small amount of ATP quickly. So ATP is made from nutrients (primarily glucose), requires oxygen for the high-yield aerobic pathway, and is produced mainly in the mitochondria.

Why condensation and hydrolysis are known as make and break reactions

Condensation is the "make" reaction: a water molecule is removed to join smaller molecules (monomers) together into larger molecules (polymers), such as building a polypeptide from amino acids.

Hydrolysis is the "break" reaction: a water molecule is added to split larger molecules into smaller ones, such as breaking a protein down into amino acids during digestion.

Three principles of a healthy diet with examples

Variety: eat a wide range of different foods so the body is exposed to the full range of nutrients. Example: rotating vegetables and protein sources through the week instead of eating the same food every day.

Balance: eat foods in appropriate proportions so you meet needs for all macronutrients and micronutrients without over-relying on one. Example: keeping calories roughly in line with recommended proportions (for instance, protein within about 10 to 35 percent of calories) rather than eating mostly one nutrient.

Moderation: don't over-indulge in any single food or nutrient, especially those high in added sugar, saturated fat, or sodium. Example: enjoying dessert occasionally in a small portion rather than every day.