1. Describe protein digestion and absorption.
2. How many amino acids are there? Of the total, how many amino acids are considered essential? List the essential amino acids. What is the difference between essential and nonessential amino acids?
3. Explain how a strict vegetarian (vegan) can be confident of getting enough of the right combinations of essential amino acids.
4. Distinguish between nitrogen equilibrium, positive nitrogen balance, and negative nitrogen balance? When in the life cycle is each of these states expected?
5. What factors affect the quality of dietary protein?
6. Ellie is eight months pregnant and has read about the various tests her baby will have when he is born. Ellie knows you are taking a nutrition class and asks you to explain the purpose and significance of one of these tests, PKU. What would you tell her?
7. Chad M. has been working out with weights for the past year. His results have been modest - the body shaping he expected developed more slowly than he had hoped. Consequently, Chad decided to increase the frequency of his workouts so that he could build more muscle mass. One of the trainers at Chad's gym learned of his goal and told him that he would have to eat more protein if he really wanted build muscle. Chad usually eats at least three meals a day, and sometimes snacks when his schedule permits. Other weight lifters at the gym told
Chad that there was no way he could get enough protein from food. They told Chad that the secret to quick muscle growth involves using a supplemental protein powder. Another friend told Chad that he should consume protein before his workouts. And another said that eating protein right after his workout would be most effective.
Chad now lifts weights four or five days a week, typically in the evening after work and classes. He also jogs or rides a stationary bike as often as he can, but he has trouble making time. Chad wants to do everything possible to meet his goal. He is 5'10" and weighs 165 pounds.
a. Using the formula in the ‘How To' box on page 185, how much protein should Chad eat? Hint: Remember that Chad is doing frequent resistance training. Use a protein requirement of 1.2 g/kg/day. Show your work.
b. Will eating a lot of protein increase the strength of Chad's muscles?
c. Do you think Chad will have to consume protein supplements to get the total amount of protein he needs?
8. List seven roles of proteins in the body and detail the importance of each role defined.