HUN1201-Chapter 7
A healthy young woman weighs 143 pounds. Calculate her RDA for protein.
52 g
What is the RDA for protein of a healthy adult woman who weighs 62 kg?
69.6 g
Explain the difference between a high-quality protein and a low-quality protein.
A high-quality or complete protein contains all essential amino acids in amounts that will support protein deposition in muscles and other tissues or support a young child's growth. A low-quality protein lacks one or more essential amino acids.
Define denaturation
A protein undergoes denaturation when it is exposed to various conditions that alter the macronutrient's natural folded and coilded shape.
Describe how Americans' food sources of protein have changed since the early 1900s.
About the same as they did in the early 1900s. But, now consume more protein from meat, fish, and poultry than from plant foods.
What is the AMDR for adult protein intake?
Adult protein intake is 10 to 35% of energy from protein
Explain why vegans must be careful when planning vegan meals for children.
Children have higher protein and energy needs per pound of body weight than adults do. Since plant foods add bulk to the diet, vegan children are more likely to eat far less food than adult vegans may be unable to eat enough plant foods to meet their protein and energy needs.
Explain why athletes should avoid taking amino acid supplements.
Comsuming supplements that contain large amounts of specific amino acids may upset intestinal cells' ability to absorb other amino acids. Little is known about the long-term safety of using protein and amino acid supplements. Excessive amounts of methionine and tyrosine can be toxic.
In cells, ___ controls the assembly of amino acids into proteins.
DNA
Explain the basic steps involved in protein synthesis.
DNA unwinds, exposing a single portion. The gene undergoes transcription to messenger RNA, mRNA transfers the information, During translation process, ribosomes "read" mRNA. each transfer RNA colecule conveys a partivular amin acid to the ribsome, IRNA attaches to the peptide chain, when complete the ribosme releases the polypeptide and the new protein further processes at other sites within the cytoplasm
_____ is the process of removing nitrogen from an amino acid.
Deamination
Define deamination
Deamination is the removal of the nitrogen-containing group from an amino acid.
Explain what happens to proteins in beans as they undergo digestion and absorption in the human digestive tract.
Denaturation by stomach acid and partial digestion by pepsin, the pancreas secretes protein-splitting enzymes including trypsin and chymotrypsin. Final digestion occurs within adsorption cells. After being absorbed amino acids enter the portal vein and travel to the liver. Very little dietary protein is excreted in feces.
Animal foods such as meat and eggs are almost 100% protein.
False
People can nourish their hair by using shampoo that contains protein.
False
Proteins are part of triglycerides.
False
Registered dietitians generally recommend that healthy people take amino acid supplements to increase their protein intake.
False
What is the "carbon skeleton" of an amino acid?
It is the part of an amino acid that remians after the amino group is removed.
Define transamination
It is the transfer of an amino group from an amino acid to a receiving compound such as a carbon skeleton.
Explain the difference between substituting high-quality proteins and extending high-quality proteins. Give examples of common foods that are high-quality substitutes for meat and foods that extend a source of high-quality protein.
It refers to replacing meat, fish and poultry with eggs, soy products, or protein-rich dairy products such as cheese, and yogurt. Extending refers to preparing dishes that incorporate small amounts of animal proteins with much larger amounts of plant proteins. Spaghetti with meat sauce is an example of a dish that extends high-quality protein in meat with more low-quality proteins in pasta.
Idenitfy at least three dietary sources of high-quality protein and three dietary sources of low-quality protein.
Most animal proteins are sources of high-quality proteins. Quinoa and processed soy proteins are also good sources of high-quality protein. Other plant foods, particularily fruits, vegetables, and grains, are sources of low-quality proteins.
Does a recipe that combines apples and oranges with peanuts provide a complementary mixture of proteins? Why or why not.
No, because fruit is not a good source of plant proteins to combine with peanuts.
In the United States, which groups of people are most likely to suffer from protein-energy malnutrition?
People suffering from alcoholism, anorexia nervosa, or certain intestinal tract disorders are at risk of protein undernutrition. This includes people with low incomes and elderly persons are at risk for protein deficiancy.
Describe conditions in which the body is in positive nitrogen balance.
Periods of rapid growth such as pregnancy, infancy, and puberty, and when people are recovering from illness or injury. Performing weight-lifting training activities also leads to nitrogen retention.
Identify nutrients that are most likely lacking in a vegan's diet.
Plant-based diets may not contain enough energy, high-quality protein, omega-3 fatty acids, vitamin B-12 and D, and minerals zinc, iron, and calcium to meet a person's nutritional needs.
Why is protein-energy malnutrition a devestating condition for young children?
Protein-energy malnutrition results when diets lack sufficient protein as well as energy.
Discuss how you can use information on a food product's label to determine whether the food is a source of high-quality protein.
Read and determine animal and soy sources of protein in the product.
Describe how the diets of semi-vegetarians differ from other vegetarian diets.
Semivegetarians consume small amounts of meat, fish, or poultry, whereas other vegetarians do not eat animal flesh.
Describe conditions that can cause the body to be in negative nitrogen balance.
Starvation, serious illnesses, and severe injuries
What is the chemical unit that makes up a protein?
The amino acid is the chemical unit that makes up a protein.
Police bring a 2-year old child into a clinic, the child has a swolen belly and feet, but the arms and upper legs are so thin, the skin hangs from them. The police report indicates the child was severely neglected by the parents. According to this information, is this child suffering from PKU, severe protein-energy malnutrition, sickle cell anemia, or anorexia nervosa?
The child probably suffers from protein-energy malnutrition because of parent neglect and presence of muscular wasting and abdominal edema.
Discuss what parents of infants with PKU can do to help their children grow and develop normally.
They must provide their children with a special diet that is very low in phenylalanine.
Americans typically consume more protein from animal sources than from plant foods.
True
Foods made from processed soybeans can be sources of high-quality protein.
True
List at least three esssential amino acids that are most likely to be limiting amino acids.
Tryptophan, threonine, lysine, methionine, and cysteine are often the limiting amino acids in foods.
How many different kinds of amino acids are needed to make human proteins? How many of these amino acids are essential?
Twenty amino acids are needed to make human proteins. Nine of these amino acids are essential.
By eating more protein than needed, a person can
absorb more calcium.
edema
accumulation of fluid in tissues
acid group
acid portion of a compound
denaturation
altering a protein's natural shape and function by exposing it to conditions such as heat, acids, and physical agitation
essential amino acids
amino acids the body cannot make or make enough to meet its needs
Identify the three groups of atoms that make up a typical amino acid.
amino or nitrogen-containing group, R-group, and acid group.
People with celiac disease should
avoid foods that contain gluten.
nitrogen balance (equilibrium)
balancing nitrogen intake with nitrogen losses
Consider your usual food choices. Using the recommendations of the MyPlate food guide, discuss ways you can intake of protein from animal foods.
buy and cook lean meats, poultry, fish-stay away from processed meats like hot dogs, lunchmeats, bacon
Which of the following tips is a recommended way to reduce food costs?
buying food in bulk, if it can be used before spoiling.
List at least four different functions of proteins in the body.
cell development and maintenance, production of enzymes, antibodies, certain hormones, structural and contractile components, and blodd-clotting factors. Additionally, proteins transport mutrients and oxygen in the bloodstream, help maintain acid-base and fluid balance, and can be used for energy.
protein turnover
cellular process of breaking down proteins and recycling their amino acids.
peptide bond
chemical attraction that connects two amino acids together
hormones
chemical messengers that regulate body processes and response
enzymes
compounds that speed up chemical reactions
kwashiorkor
form of undernutrition that result from consuming adequate energy and insufficient high-quality protein
Which of the following foods generally provides the least amount of protein per serving?
fruits
pepsin
gastric enzyme that breaks down proteins into smaller polypeptides
nonessential amino acids
group of amino acids that the body can make
A protein
has nitrogen in its chemical structure.
DNA
hereditary material that provideds instructions for making proteins
List three common signs or symptoms of food allergy and celiac disease.
hives, swollen or itchy lips, skin flushing, eczema, difficulty swallowing, wheezing and difficulty breathing, abdominal pains, vomiting and diarrhea. Celiac disease are adbominal bloating, chronic diarrhea, weight loss and poor growth in children.
Which of the following foods is not a source of complementary protein?
hummus on a pita bread
Which of the following physical states is (are) characterized by positive nitrogen balance?
illness
antibodies
infection-fighting proteins
Proteins
large, complex organic molecules made up of amino acids
acid-base balance
maintaining the proper pH of body fluids
complementary combinations
mixing certain plant foods to provide all essential amino acids without adding animal protein
amino acid
nitrogen-containing chemical units that comprise proteins
A recipe mixes cereals made from wheat, rice, and corn. What plant foods could you add to this combination of cereals to make the recipe a source of high-quality protein?
nuts, dry beans, quinoa or seeds will compliment the cereal protein.
A person following a vegan diet would eat
nuts.
R group (side chain)
part of amino acid that determines the molecule's physical and chemical properties
Which of the following foods is not a source of complete protein?
peanut butter
vegetarians
people who eat plant-based diets
legumes
plants that produce pods with a single row of seeds
gene
portion of DNA
amino or nitrogen-containing group
portion of an amino acid that contains nitrogen
high-quality (complete) protein
protein that contains all essential amino acids in amounts that support the deposition of protein in tissues and the growth of a young person
low-quality (incomplete) protein
protein that lacks or has inadequate amounts of one or more of the essential amino acids
polypeptides
proteins comprised of 50 or more amino acids
deamination
removal of the nitrogen-containing group from an amino acid
peptides
small chains of amino acids
marasmus
starvation
negative nitrogen balance
state in which the body loses more nitrgen than it retains
positive nitrogen balance
state in which the body retains more nitrogen than it loses
buffer
substance that can protect the pH of a solution
transamination
transfer of the nitrogen-containing group from an unneeded amino acid to a carbon skeleton to form an amino acid
Lactovegetarian
vegetarian who consumes milk and milk products for animal protein
lactoovovegetarian
vegetarian who consumes milk products and eggs for animal protein
ovovegetarian
vegetarian who eats eggs for animal protein
vegan
vegetarian who eats only plant foods
urea
waste product of amino acid metabolism