Question 1

Which of the following vitamins is typically lacking in a poorly planned vegetarian diet?

Accepted Answer

Vitamin D is often lacking in poorly planned vegetarian diets because it is primarily obtained from sunlight exposure and certain animal products. Vegetarians might not get enough if they don't consume fortified foods or spend limited time in the sun.

Question 2

How many amino acids are considered indispensable/essential?

Accepted Answer

There are 9 amino acids considered indispensable or essential for humans because the body cannot synthesize them and they must be obtained through diet. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Question 3

Which cooking method would you use to maximize the digestibility of protein?

Accepted Answer

Boiling is considered the best method to maximize the digestibility of protein because it gently cooks the protein without causing the formation of tough, hard-to-digest compounds that can form during high-temperature cooking methods like grilling, frying, and baking.

Question 4

Proteins attract water and hold it within blood vessels, preventing it from freely flowing into the spaces between the cells. Which of the following will an individual develop should any part of this system begin to fail?

Accepted Answer

When proteins fail to hold water within blood vessels, it leads to an accumulation of fluid in the spaces between cells, causing swelling or edema.

Question 5

Which of the following conditions can cause denaturation of proteins?

Accepted Answer

Heat exposure can cause denaturation of proteins by disrupting the hydrogen bonds and non-covalent interactions that maintain their structure.

Question 6

Which of the following electrolytes is concentrated inside the body's cells?

Accepted Answer

Potassium is the major cation (positive ion) found inside cells, playing a crucial role in maintaining cell function and the overall balance of body fluids.

Question 7

Which symptom would a child with marasmus exhibit?

Accepted Answer

Marasmus is characterized by severe undernutrition, leading to significant weight loss and muscle wasting, often resulting in dry, thin, and wrinkled skin.

Question 8

According to the Dietary Reference Intakes (DRI) committee, minimum protein intake should be what percentage of total Calories?

Accepted Answer

The Dietary Reference Intakes (DRI) committee recommends that protein intake should be 10% of total calories. This is a guideline to ensure adequate protein intake for the general population.

Question 9

Which of the following foods has the highest protein digestibility-corrected amino acid score (PDCAAS)?

Accepted Answer

Tuna has the highest Protein Digestibility-Corrected Amino Acid Score (PDCAAS) among the options listed. PDCAAS is a method of evaluating the protein quality based on both the amino acid requirements of humans and their ability to digest it. Animal proteins like tuna generally have higher PDCAAS values than plant proteins because they contain all the essential amino acids in proportions closer to those required by humans.

Question 10

Based on the body's priority system, what protein tissues are dismantled first?

Accepted Answer

The body prioritizes the preservation of vital organs such as the heart, kidney, and liver, so when it needs to dismantle protein tissues for energy or repair, it will first target less critical tissues like those in the blood, specifically proteins in the plasma.

Question 11

In determining its recommendation for daily protein intake needs, the Dietary Reference Intakes (DRI) committee made use of studies related to what topic?

Accepted Answer

The DRI committee used studies related to nitrogen balance to determine recommendations for daily protein intake needs. Nitrogen balance studies help in understanding how much protein is needed to balance the amount of nitrogen consumed with the amount excreted, indicating the body's protein needs for maintenance and growth.

Question 12

Which of the following components is a protein catalyst that acts on other substances to change them chemically?

Accepted Answer

Enzymes are protein catalysts that speed up chemical reactions in cells by lowering the activation energy required for the reaction to occur. They are crucial for various metabolic processes.

Question 13

What type of protein does the body's immune system need to manufacture in order to fight influenza and develop immunity?

Accepted Answer

Antibodies are the proteins that the immune system produces in response to antigens (such as those found on influenza viruses) to neutralize or destroy them, thereby developing immunity against future infections.

Question 14

According to the Dietary Reference Intakes (DRI) committee, a healthy adult's intake for protein should be how many grams for each kilogram of body weight?

Accepted Answer

The Dietary Reference Intakes (DRI) recommend 0.8 grams of protein per kilogram of body weight for healthy adults.

Question 15

Which of the following food items provides all the essential amino acids?

Accepted Answer

Poached eggs are a complete protein source, meaning they contain all nine essential amino acids that the human body cannot synthesize on its own and must obtain from food.

Question 16

Which substance protects the stomach lining from the very strong acid of the stomach?

Accepted Answer

Mucus protects the stomach lining from the very strong acid (hydrochloric acid) in the stomach. It acts as a barrier and lubricant, preventing the acid from damaging the stomach walls.

Question 17

Which term refers to the chronic Calorie-deficiency disease that takes the form of extreme loss of muscle and fat?

Accepted Answer

Marasmus is characterized by severe undernourishment causing a child's weight to be significantly low for their age. It involves extreme loss of muscle and fat due to a deficiency in calories and protein.

Question 18

For which of the following vitamins is the amino acid tryptophan the starting material?

Accepted Answer

Tryptophan is an essential amino acid that serves as a precursor for the synthesis of niacin (vitamin B3) in the human body. This process also requires the presence of other nutrients such as iron, riboflavin, and vitamin B6.

Question 19

What factor determines the sequences of amino acids that make up a protein molecule?

Accepted Answer

The sequence of amino acids in a protein molecule is determined by the nucleotide sequence of the gene encoding that protein, which is a hereditary factor passed down from parents to offspring.

Question 20

The protein digestibility-corrected amino acid score (PDCAAS) takes which of the following factors into account?

Accepted Answer

PDCAAS evaluates the quality of a food protein based on its amino acid composition and digestibility, not on the length of time for protein breakdown, its impact on weight gain, or the sheer number of amino acids in the food.

Quiz 6: The Proteins and Amino Acids