Nutrition Practice Exams: Vitamins, Proteins, and Lipids

A comprehensive vocabulary review deck of 150 practice exam flashcards covering vitamins (Chapter 7), protein structure and metabolism (Chapter 6), and lipids and cardiovascular health (Chapter 5).

Vitamins

Tasteless, organic compounds needed for growth and metabolic functions that do not provide cellular energy.

Micelle

A spherical transport structure composed of bile salts and fatty acids that facilitates the intestinal absorption of fat-soluble vitamins such as vitamin A.

Cold

An environmental condition that preserves and will not destroy the vitamin content of foods, unlike heat, water, and air.

Xerophthalmia

Permanent, irreversible damage to the cornea of the eye resulting from a prolonged deficiency of vitamin A.

Alpha-Tocopherol

The naturally occurring, biologically active form of vitamin E.

Riboflavin

A light-sensitive B vitamin (vitamin B2) that is abundant in dairy milk.

Vitamin K

An essential fat-soluble vitamin necessary for blood clotting and enabling osteocalcin to bind with calcium in bone tissue.

Folate

A critical B vitamin recommended in a woman's diet before conception to support neural tube development, also essential for red blood cell synthesis.

Colon Cancer Reduction (Folate)

The proven protective effect of dietary folate in reducing the risk of specific malignancies, particularly colon cancer.

Collagen Production (Vitamin C)

The essential physiological process requiring vitamin C (ascorbic acid) as an indispensable coenzyme.

Pellagra

A clinical disease caused by a severe deficiency of vitamin B3 (niacin).

Rickets

A bone-softening deficiency disease occurring in children caused by an inadequate supply of vitamin D.

Scurvy

A severe nutritional deficiency disease caused by a lack of dietary vitamin C, characterized by collagen breakdown.

Rickets Etiological Factors

Environmental and behavioral factors causing an increase in pediatric rickets in the United States, including air pollution, reduced outdoor activity, and increased use of sunscreens.

Vitamin C Synthesis

A biosynthetic capability absent in the human body, requiring that all vitamin C be obtained through the diet.

Beriberi

A severe deficiency condition impacting the cardiovascular and nervous systems resulting from an inadequate intake of thiamin (vitamin B1).

Anthocyanin

A bioactive phytochemical antioxidant responsible for the deep pigment found in beets.

Niacin (Serum Triglyceride Reduction)

The pharmacological and nutritional action of vitamin B3 shown to beneficially improve circulating serum levels of triglycerides.

Hand-Washing

The most effective behavioral measure to reduce the risk of contracting the common cold, superior to vitamin C or Echinacea supplementation.

Homocysteine Breakdown (Folate)

The metabolic process in which folate assists in degrading homocysteine in the blood to reduce cardiovascular risk.

Biotin

A water-soluble B vitamin functioning as a metabolic coenzyme that does not act as an antioxidant.

Dietary Folate Sources

Nutrient-dense plant foods, such as beans and legumes, that provide exceptionally high natural concentrations of folate.

Naturally Occurring Vitamin B12

Cobalamin obtained exclusively from animal-derived dietary sources such as eggs, meat, and dairy products.

Vitamin B12 Absorption Decline

The physiological reality that intestinal absorption of vitamin B12 typically decreases, rather than increases, with advancing age.

Pernicious Anemia

An autoimmune or physiological condition in which a lack of gastric intrinsic factor prevents the intestinal absorption of vitamin B12.

Fortified Food Consumers

Individuals who consume foods with added micronutrients and are therefore least likely to require additional commercial dietary supplements.

National Eye Institute Macular Degeneration Formula

A specific protective antioxidant regimen of vitamin C, vitamin E, and beta-carotene proven to lower the risk of age-related macular degeneration.

Vitamin D Activation Pathway

The two-step metabolic conversion in which inactive vitamin D is transformed into its active hormonal form: first in the liver and subsequently in the kidneys.

Calcium and Phosphorus Regulation (Vitamin D)

The primary endocrine mechanism by which vitamin D maintains skeletal health and bone mineral density.

Osteocalcin Binding (Vitamin K)

The biochemical carboxylation process mediated by vitamin K that enables the bone protein osteocalcin to bind with calcium.

Coenzymes

Molecules derived from B vitamins that bind with enzymes to facilitate chemical reactions within biological cells.

Ascorbic Acid

The chemical and physiological name for vitamin C.

Fortified Foods

Food products that have had extra nutrients artificially added to enrich their nutritional profile.

USP (United States Pharmacopeia)

The independent scientific organization responsible for setting recognized standards of purity, quality, and reliability for dietary supplements.

Folate and Vitamin B12

Two synergistic B vitamins required to support proper erythrocyte formation and maintain healthy red blood cells.

Carnitine

A vitamin-like substance abundant in foods from animal sources that is required for the cellular utilization and mitochondrial transport of fatty acids.

Free Radicals

Highly reactive, oxygen-containing molecules that inflict damage on cellular components and elevate the risk of chronic diseases.

Water-Soluble Vitamin Excretion

The primary physiological clearance pathway whereby excess water-soluble vitamins are filtered out of the blood and excreted in the urine.

Alcohol Metabolism (Niacin)

The hepatic enzymatic breakdown of ethanol that directly utilizes niacin as a coenzyme component.

The Three Ds of Pellagra

The triad of hallmark signs characterizing severe niacin deficiency: dermatitis, dementia, and diarrhea.

Tryptophan Conversion

The metabolic pathway through which the essential amino acid tryptophan is converted endogenously into niacin.

Pyridoxine

A major chemical compound included within the collective group of substances known as vitamin B6.

White Blood Cell Synthesis (Vitamin C)

The immune-enhancing action of vitamin C that stimulates the body to produce protective leukocytes.

Dietary Antioxidants

Compounds including vitamin E, vitamin C, and beta-carotene that scavenge free radicals, potentially reducing risks of cardiovascular disease, cancer, arthritis, and Alzheimer's disease.

Non-Heme Iron Absorption

The gastrointestinal uptake of plant-based iron from cereals and grains that is greatly enhanced by the presence of ascorbic acid.

Collagen

A structural protein whose synthesis depends on ascorbic acid acting as a biochemical coenzyme.

Cataract

A degenerative eye disorder characterized by the progressive clouding of the lens.

Phytochemicals

Naturally occurring plant compounds that act as antioxidants and impart vibrant colors to fruits and vegetables.

Intrinsic Factor

A gastric glycoprotein necessary for the receptor-mediated intestinal absorption of vitamin B12.

Vitamin A

A fat-soluble micronutrient absorbed through micellar structures that is critical for corneal health, immune function, and vision.

Proteins

Complex organic polymers composed of linked amino acids found throughout every living cell in the human body.

Sickle-Cell Anemia

The most common inherited blood disorder in the United States, caused by an amino acid substitution in hemoglobin.

Denaturing Agents (Proteins)

Physicochemical factors such as acids, heat, and mechanical agitation that alter a protein's tertiary structure and render it biologically inactive.

Pepsin

The active gastric protease that initiates the enzymatic cleavage of dietary proteins within the stomach.

tRNA (Transfer RNA)

The specialized RNA molecule that binds and transports a specific amino acid to the ribosome during protein translation.

Collagen (Structural Support)

A fibrous triple-helical protein that supplies mechanical strength and structural integrity to connective tissues.

Positive Nitrogen Balance

A metabolic state where nitrogen consumption exceeds nitrogen output, typically observed during pregnancy and rapid growth.

Adult Protein Requirement

The Recommended Dietary Allowance (RDA) stating that healthy adults age $19$ and older should consume $0.8\,g/kg$ of body weight daily.

Protein Needs in Overweight Individuals

The nutritional principle that an overweight individual's absolute protein requirement is not much greater than that of a normal-weight person of comparable height.

Protein RDA for 125-lb Female

An intake of approximately $45\,g$ of protein daily, calculated using $125\text{ lbs} \div 2.2\,lbs/kg \times 0.8\,g/kg$.

Low-Protein Food Sources

Fresh watery fruits such as melon ($1\text{ cup}$), which provide negligible dietary protein relative to dairy, legumes, grains, or vegetables.

PEM Etiology

Underlying societal and physiological drivers of protein-energy malnutrition, including poverty, poor food quality, and premature cessation of breastfeeding (excluding obesity).

High-Protein Diet Nutrient Gaps

Dietary omissions typical of high-protein, low-carbohydrate eating plans, most notably the elimination of fresh fruits.

Enzymes

Specialized proteins acting as biological catalysts that speed up chemical reaction rates without being altered themselves.

Buffers

Circulating and cellular proteins that stabilize systemic acid-base balance by minimizing fluctuations in pH.

Gene

A distinct segment of DNA containing the nucleotide sequence coding for the synthesis of a specific polypeptide or protein.

Denaturation Functional Outcome

The loss of native conformation in a protein that disrupts its chemical binding properties and causes alterations in its physiological function.

High-Protein Diet Risks

Clinical health concerns associated with excessive dietary protein intake, including increased risks for kidney stones, accelerated osteoporosis, and heart disease (excluding PKU).

Vegetarian Disease Reductions

Documented health advantages of vegetarian eating patterns, including lower rates of cardiovascular disease, type 2 diabetes, and specific malignancies (with no effect on colds).

Ovo-Vegetarian

A vegetarian dietary pattern that includes eggs (such as an omelet) but excludes dairy products like cheese and animal meats.

Soy and Breast Cancer Risk

A clinical concern indicating that excessive soy consumption may be harmful for women identified as being at high risk for developing breast cancer.

Vegetarian Vitamin B12 Risk

The primary micronutrient vulnerability facing strict vegetarians, who risk deficiency because natural vitamin B12 is found only in foods of animal origin.

Kwashiorkor

A life-threatening clinical syndrome resulting from a severe, acute deficiency of dietary protein despite receiving sufficient dietary calories.

Protein Complementation

The culinary strategy of combining two incomplete plant protein sources (such as rice and vegetables) so their amino acid profiles complement one another.

Histidine

An amino acid previously considered essential exclusively in infant nutrition that is now established as essential across all stages of human life.

Small Intestine (Protein Absorption)

The principal anatomical organ where broken-down dipeptides, tripeptides, and free amino acids are absorbed across the brush border into circulation.

Peptide Bond

The covalent chemical bond linking the amino group of one amino acid to the adjacent carboxyl group of another within a protein chain.

Satiety (Protein Impact)

The postprandial sensation of prolonged gastric fullness and hunger suppression, which protein promotes to a greater degree than either carbohydrates or fats.

Limiting Amino Acid

The specific essential amino acid that is in the shortest supply relative to human physiological needs within an incomplete protein source.

Vegan Diet

A complete plant-based eating pattern that strictly eliminates all foods of animal origin, including meat, dairy, eggs, and animal-derived ingredients.

PDCAAS

Protein Digestibility Corrected Amino Acid Score, an index evaluating dietary protein quality based on its essential amino acid profile and digestive bioavailability.

Starvation Nitrogen Balance

A metabolic state of negative nitrogen balance wherein the catabolism of endogenous body proteins exceeds nitrogen ingestion.

Edema in Kwashiorkor

The severe fluid accumulation causing swelling in the legs, feet, and distended abdomen characteristic of advanced kwashiorkor.

Osteoporosis Dietary Factors

The skeletal condition aggravated by consuming a diet excessively high in animal protein combined with an inadequate dietary calcium intake.

Protein-Energy Malnutrition (PEM)

A spectrum of nutritional wasting disorders resulting from chronic deficits in both protein and total energy intake.

Collagen (Abundance)

The single most abundant structural protein found within the human body.

Isoflavones

Naturally occurring phytoestrogens in soy foods that possess a molecular structure similar to human estrogen.

Soy Intake in Adolescence

A preventative dietary factor documented in Chinese women where high soy consumption during teenage years correlated with reduced breast cancer risk in adulthood.

AMDR for Protein

The Acceptable Macronutrient Distribution Range recommending that individuals consume between $10$ and $35\%$ of their total daily calories from protein.

Phytate

A mineral-binding compound found in whole grains and legumes that inhibits the intestinal bioavailability and absorption of zinc and iron.

Kwashiorkor Diet Profile

A dietary intake pattern that is heavily dominated by carbohydrates while being pathologically deficient in protein.

Adolescent Protein RDA

The dietary protein recommendation stipulating that growing individuals aged $18$ and younger should consume $0.85\,g/kg$ of body weight daily.

Protein Caloric Yield

The physiological fuel value of dietary protein, providing exactly $4\text{ calories}$ of metabolizable energy per gram.

Fever Nitrogen Balance

The catabolic state of negative nitrogen balance that occurs when a patient is mobilizing body tissue stores while fighting an active infection or fever.

Urea

The non-toxic nitrogenous waste product synthesized by the liver from toxic deaminated ammonia, which is subsequently eliminated in the urine.

Adipose Storage of Excess Calories

The physiological conversion pathway whereby surplus calories consumed beyond metabolic needs are converted and stored as body fat.

Marasmus

A state of severe protein-energy malnutrition characterized by emaciation and muscle wasting resulting from a chronic deficiency of total calories.

DNA (Protein Synthesis)

The double-stranded genetic material in the cell nucleus that encodes and directs the sequence of all cellular protein synthesis.

Nonessential Amino Acid

An amino acid that the human body can synthesize endogenously from metabolic precursors to satisfy physiological needs.

Phenylketonuria (PKU)

A rare inherited genetic metabolic disease caused by an inability to properly break down and metabolize the amino acid phenylalanine.