Nutrition Practice Exam: Lipids, Proteins, Vitamins, and Minerals

Comprehensive practice flashcards covering lipid biochemistry, protein metabolism, essential vitamins, and fluid and mineral balance from Chapters 5, 6, 7, and 8.

What is the condition hyponatremia and what causes it?

The presence of too little sodium in the blood due to the overconsumption of fluids.

Approximately what percentage of an average healthy adult's body is composed of water?

$50\% \text{ to } 60\%$ water.

Which two minerals combine to form hydroxyapatite in bones and teeth?

Phosphorus and calcium.

In the DASH study, what daily sodium intake level was found to be the most effective limit for lowering blood pressure?

$1{,}500\,\text{mg}$.

What is the difference between hypokalemia and hyperkalemia?

Hypokalemia is defined as too little potassium in the blood, whereas hyperkalemia occurs when a person consumes too much potassium from supplements.

What are the characteristic signs and symptoms of cretinism, resulting from iodine deficiency?

Dwarfism, mental retardation, and abnormal sexual development.

Toxicity of which trace mineral can damage the nervous system and produce symptoms that resemble Parkinson's disease?

Manganese.

What is hemochromatosis?

A genetic disorder in which individuals absorb too much dietary iron.

What is the primary role of chromium in cellular metabolism?

To increase the effectiveness of insulin in cells.

How is vitamin A transported through the body after digestion?

In a micelle along with bile and fatty acids.

What is xerophthalmia?

Permanent damage to the cornea resulting from a vitamin A deficiency.

What deficiency disease is caused by a lack of vitamin B3 (niacin), and what are its primary signs and symptoms?

Pellagra; its characteristic signs and symptoms include dermatitis, dementia, and diarrhea.

At which anatomical sites is the inactive form of vitamin D converted into its active form?

First in the liver and then in the kidneys.

Which condition results from a deficiency of thiamin (vitamin B1)?

Beriberi.

Why does pernicious anemia develop in individuals who lack intrinsic factor?

Intrinsic factor is required for the absorption of vitamin B12; without it, vitamin B12 cannot be absorbed, leading to pernicious anemia.

What two important physiological roles are performed by vitamin K?

It is essential for blood clotting and enables osteocalcin to bind with calcium in bones.

From which amino acid can the human body synthesize niacin?

Tryptophan.

What is carnitine and what is its role in metabolism?

A vitamin-like substance abundant in foods from animal sources that is needed to properly utilize fat.

What are the recommended dietary protein intakes per kilogram of body weight for adults versus individuals $18$ years of age and younger?

Average adults (age $19$ and older) should consume $0.8\,\text{g/kg}$, while individuals $18$ years of age and younger should consume $0.85\,\text{g/kg}$.

How do pregnancy and starvation differ in terms of nitrogen balance?

A pregnant woman is typically in positive nitrogen balance, whereas a starving individual is in negative nitrogen balance.

What is the energy yield per gram of protein, and what percentage of total daily calories should come from protein?

Protein yields $4\,\text{calories per gram}$, and the recommended intake is $10\% \text{ to } 35\%$ of total daily calories.

What enzyme initiates the chemical digestion of protein within the stomach?

Pepsin.

How do the malnutrition conditions kwashiorkor and marasmus differ in etiology?

Kwashiorkor is caused by a severe deficiency of dietary protein (often showing edema), whereas marasmus is characterized by a severe deficiency of calories.

What is the term for the amino acid in the shortest supply within an incomplete protein?

The limiting amino acid.

What compound is produced when the liver converts ammonia generated from the deamination of amino acids?

Urea, which is excreted in the urine.

What is phenylketonuria (PKU)?

A rare genetic disorder caused by the body's inability to properly degrade the amino acid phenylalanine.

Which compound found in plant grains inhibits the absorption of iron and zinc in vegetarians?

Phytate (phytates).

What are the two essential fatty acids required by the human body?

Linoleic acid and alpha-linolenic acid.

What is the energy content of fat per gram, and what is the current AMDR recommendation for fat intake?

Fat provides $9\,\text{calories per gram}$, and the AMDR recommendation is $20\% \text{ to } 35\%$ of total daily calories.

How many glycerol and fatty acid molecules are present in a sterol molecule?

$0$ glycerol and $0$ fatty acid groups (sterols consist of four connecting rings of carbon and hydrogen).

Which lipoprotein contains the highest percentage of protein, and which contains the highest percentage of cholesterol?

HDL contains the highest percentage of protein, while LDL contains the highest cholesterol content.

Through which system do chylomicrons initially transport dietary lipids away from the intestinal tract?

The lymphatic system.

What impact do trans fats have on serum LDL and HDL cholesterol levels?

Trans fat consumption raises LDL levels and lowers HDL levels.

What do elevated levels of C-reactive protein (CRP) in the blood indicate regarding cardiovascular risk?

They indicate the presence of inflammation in the walls of the arteries.

What mandatory fortification does the FDA require for food products containing olestra?

Fat-soluble vitamins.

Which types of eicosanoids are synthesized in the body from essential fatty acids?

Prostaglandins, thromboxanes, and leukotrienes.