Question 1

Which of the following statements best describes the structure of an amino acid?

Accepted Answer

Each amino acid contains an acid group (COOH), an amine group (NH2), and a unique side chain attached to a central carbon.

Question 2

What is the primary function of peptide bonds in protein structure?

Accepted Answer

Peptide bonds link the acid group of one amino acid to the amine group of another, forming polypeptide chains.

Question 3

Which scenario best illustrates a conditionally essential amino acid?

Accepted Answer

A premature infant requires dietary cysteine due to inadequate enzyme activity for synthesis.

Question 4

What is the effect of denaturation on a protein’s function?

Accepted Answer

Denaturation alters the protein’s shape, which changes its structure and function.

Question 5

During protein digestion, which enzyme is activated by stomach acid to begin breaking down proteins?

Accepted Answer

Pepsin

Question 6

After the amine group is removed from an amino acid, which of the following is NOT a possible fate for the remaining carbon skeleton?

Accepted Answer

It can be used to synthesize DNA.

Question 7

Which equation correctly calculates daily protein needs for an adult weighing 150 pounds?

Accepted Answer

Divide 150 by 2.2 to get kilograms, then multiply by 0.8: $$150 \div 2.2 	imes 0.8$$

Question 8

A patient with edema is most likely suffering from which protein-related issue?

Accepted Answer

Insufficient protein intake leading to poor fluid balance.

Question 9

Which of the following is a complete protein source?

Accepted Answer

Quinoa

Question 10

What is the Protein Digestibility Corrected Amino Acid Score (PDCAAS) used for?

Accepted Answer

To assess protein quality based on digestibility and amino acid profile.

Question 11

Which scenario represents positive nitrogen balance?

Accepted Answer

A pregnant woman retaining more nitrogen for protein synthesis.

Question 12

Which of the following is a risk associated with consuming too much protein?

Accepted Answer

Increased risk of heart disease and kidney stones.

Question 13

A child weaned to a low-protein cereal diet develops edema, muscle loss, and skin rashes. What is the most likely diagnosis?

Accepted Answer

Kwashiorkor

Question 14

Which combination of plant foods would best provide complementary proteins?

Accepted Answer

Rice and beans

Question 15

Which nutrient is most likely to be deficient in a strict vegan diet without supplementation?

Accepted Answer

Vitamin B12

Question 16

Which of the following is NOT a benefit of a vegetarian diet?

Accepted Answer

Increased risk of obesity

Question 17

Which protein-rich soy food is made from cooked, condensed whole soybeans and can be used as a meat substitute?

Accepted Answer

Tempeh

Question 18

A vegan is concerned about omega-3 fatty acid intake. Which plant food would best help meet this need?

Accepted Answer

Flaxseed

Question 19

Which equation represents the energy provided by protein per gram?

Accepted Answer

$$	ext{Energy (kcal)} = 	ext{Protein (g)} 	imes 4$$

Question 20

Which of the following is a plausible risk of high-protein, low-carbohydrate diets?

Accepted Answer

Restrictive diet, decreased kidney function, and reduced fiber intake.

Proteins and Amino Acids: Structure, Function, and Dietary Importance

Study Guide - Practice Questions