PROTEIN
DNT 200 — NUTRITION FOR HEALTH SCIENCES
STUDY GUIDE 5: PROTEIN
Directions. Using Chapter 6 of your textbook as a reference answer the following questions. Please include the questions with your answers. Be sure to put your name on your document. Your answers should be thoughtful, complete, and in Standard English. Credit will not be given for answers copied from online sources.
1. Define the following:
Acids
Amino Acids
Amino Acid Pool
Ammonia
Antibodies
Antigens
Bases
Branch-chain amino acids
Buffers
Carcinogen
Collagen
Complementary Proteins
Conditionally Essential Amino Acid
Deamination
Denaturation
Dipeptide
Edema
Enzymes
Essential Amino Acids
Fluid Balance
Gene expression
Hemoglobin
High Quality Proteins
Keto acid
Immunity
Limiting Amino Acid
Matrix
Neurotransmitters
Nitrogen Balance
Nonessential Amino Acids
Pepsin
Peptidase
Peptide Bond
Polypeptide
Processed meat
Protein
Protein digestibility
Protein turnover
Red meat
Reference Protein
Serotonin
Sickle Cell Anemia
Transamination
Transcription
Translation
Tripeptide
Urea
Whey protein
2. Using the information from Chapter 6 in your text, describe protein digestion and absorption. Be thorough.
3.
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?
4.
Nicole A. is a strict vegetarian (vegan). How can she be confident of getting enough of the right combinations of essential amino acids?
5.
Distinguish between nitrogen equilibrium, positive nitrogen balance, and negative nitrogen balance? When in the life cycle is each of these states expected?
6.
What two factors affect the quality of dietary protein?
7.
Ellie H. 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?
8.
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 5’11” and weighs 170 pounds.
a. Using the formula in the ‘How To 6-1’ box on page 186, how much protein should Chad eat? Hint: Remember that Chad is doing frequent resistance training. Since Chad is a power athlete use a protein requirement of 1.2 g/kg/day. Show your work.
b.
Do you think Chad will have to consume protein supplements to get the total amount of protein he needs?
9.
List seven roles of proteins in the body and detail the importance of each role defined.
10.
Kyla C. is a 27-year-old accountant who is 5 feet 8 inches tall and vigilantly maintains her weight at 118 pounds by following a lacto-ovo (non-fat milk and egg whites only) vegetarian diet that supplies approximately 1200 kcalories a day. With her understanding that protein should provide between 10 and 35 percent of her daily calories, she reasons that her daily intake of 40 grams of protein from milk, eggs, legumes, and nuts is adequate for her needs. She is concerned, however, that she has been sick more than usual and has experienced two stress fractures in her leg over the past three years while exercising.
a.
Explain why Kyla’s assumptions about her protein needs are unrealistic based on her current weight.
b.
Assuming a healthy weight for Kyla is 141 pounds, use the information from the “How to” feature (p. 186) in your text to calculate her recommended daily protein requirement. Show your calculations.
c.
What percentage of Kyla’s current energy intake comes from protein? Show your work. Remember that protein provides approximately 4 kcalories per gram. Is this adequate? Why or why not?
d.
Kyla’s energy needs for a healthy weight are closer to 1600 kcalories a day. How might her low calorie intake influence her protein status and possibly contribute to her current health issues?
e.
How would you explain to Kyla that her low intake of calories and protein contribute to her risk for osteoporosis?
f.
Assuming that Kyla consumes 20 grams of protein from whole grains, vegetables, and legumes each day, calculate how she can meet the remainder of her protein needs with dairy foods and egg whites. Use the following values as a starting point, 1 cup of milk = 8 grams of protein, and 1 egg white = 7 grams of protein. Show your work.
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