Ch 6 Nutrition: Proteins and Amino Acids

The variable part of an amino acid is the _____. a. acid group b. amino group c. backbone d. side chain

Proteins can be denatured by all of the following EXCEPT _____. a. mercury b. stomach acid c. heat d. freezing e. radiation

Would you recommend an amino acid supplement to a friend who is recovering from illness and wants to promote muscle mass gain? Why or why not? a. Yes, amino acid supplements are an excellent way to quickly provide energy to muscles for rebuilding. b. Yes, taking amino acid supplements helps keep the digestive system from overworking while you recover from illness. c. No; extra carbohydrate and fat, but not extra protein, are needed for recovery from illness. d. Yes, but one should also do plenty of exercise to promote muscle regain. e. No; whole protein is better handled by the digestive system and will promote muscle mass gain better than amino acid supplements.

Which statement regarding digestion and absorption of proteins is true? a. Cells in the small intestine possess different sites for absorbing different types of amino acids, which causes competition among amino acids at the absorption sites. b. Proteins are broken down into individual amino acids and absorbed by all intestinal cells at an equal rate. c. Larger peptide molecules must be completely broken down into amino acids to be absorbed into the bloodstream from the intestine. d. Amino acids need a carrier in the bloodstream because they do not transport very well alone. e. Protein digestion and absorption require some form of carbohydrate.

The process of protein turnover involves the _____. a. conversion of half the protein we eat to glucose for energy b. loss of amino acids by excretion through the kidneys when cells die c. use of amino acids that have been conserved from the breakdown of old cells d. annual replacement of old cells with new protein that has entered the body in food e. excretion of intracellular working proteins as old cells wear out

Proteins play several important roles in the body. What is NOT one of these? a. maintaining acid-base balance b. serving as antibodies c. providing an unlimited supply of energy d. maintaining fluid and electrolyte balance e. regulating gene expression

What is an important function of the amino acid tyrosine? a. It is used to make the neurotransmitter serotonin. b. It is used to make the brown pigment melanin. c. It is converted into the hormone insulin. d. It is used to make the vitamin niacin. e. It is a precursor of vitamin C

The most easily digestible form of protein can be found in which of the following foods? a. pasta b. black beans c. peppers d. peanuts e. eggs

Who would benefit most from eating a variety of protein foods so that amino acids that are low in some foods will be supplied by the others? a. a vegan b. a lacto-ovo vegetarian c. a carnivore d. an omnivore e. a pregnant woman

Which of the following is NOT a consequence of protein deficiency? a. slow growth in children b. increased nutrient absorption from the digestive tract c. a weakened immune system d. impaired brain and kidney function e. negative nitrogen balanc

What advice would you give to a friend who has started a gluten-free diet to lose weight? a. She should be successful because it is an excellent way to lose weight. b. The gluten-free diet will help relieve any digestive symptoms she may have. c. Gluten-free diets are useful because they also help prevent cancer. d. Gluten-free weight-loss diets offer no advantages over other low-calorie diets. e. Even if she does not have celiac disease, she will benefit from removing gluten from her diet.

Heavy use of soy products in place of meat can inhibit absorption of what nutrient? a. phytochemicals b. Iron c. vitamin C d. zinc e. B12

What is required for legumes to "fix" nitrogen? a. bacteria b. fertilizer c. UV light d. crop rotation e. genetic modification

Which protein-rich food would be a good source of calcium for vegetarians? a. margarine b. flaxseeds c. kidney beans d. eggs e. almonds

What is NOT one of the beneficial characteristics of a vegetarian diet? a. It provides more phytochemicals. b. It provides more antioxidant nutrients and fiber. c. It provides more saturated fat. d. It promotes a leaner body type. e. It reduces the risk of cancer