Chapter 7-Proteins
How do you calculate the RDA for protein?
-convert weight from pounds to kilograms -calculate RDA by multiplying weight in kilograms by 0.8g of protein
the RDA for protein is _____g/kg body weight
0.8
list the steps of the digestion and absorption of protein: liver large intestine stomach small intestine pancreas
1. stomach 2. pancreas 3. small intestine 4. liver 5. large intestine
how many pounds are in a kilogram?
2.2 pounds
Which of the following is associated with excessive protein intakes? a. dehydration b. anemia c. diarrhea d. diabetes
a. dehydration
Which of the following is NOT a usual characteristic of marasmus? a. edema b. severe weight loss c. impaired growth d. muscle wasting
a. edema
The sequential order of amino acids in a polypeptide chain is called the _______________. a. primary structure b. secondary structure c. tertiary structure d. quaternary structure
a. primary structure
The carbon skeleton of an amino acid is the portion remaining after an amino group has been removed a. true b. false
a. true
essential amino acids must be supplied by the diet because the body cannot synthesize them in adequate amounts a. true b. false
a. true
The complementary mRNA nucleotide of thymine is _________ and the complementary tRNA is ___________
adenine; uracil
What is the fate of excess intake of dietary protein?
after absorption, the extra amino acids will be rapidly degraded and used to make glucose for energy or to make fat for storage
What are the nonessential amino acids?
alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine
components, typically proteins that induce a hypersensitive response, which excess production of certain immune system antibodies. subsequent exposure to the same protein leads to allergic symptoms
allergen
lack of an immune response to foreign compounds entering the body.
anergy
Which of the following is classified as a complete protein? a. kidney beans b. fat-free milk c. whole-grain bread d. corn tortillas
b. fat-free milk
measure of how efficiently the absorbed food protein is converted into body tissue protein
biological value
compounds that help maintain acid-base balance within a narrow range
buffers
Proteins are involved in all of the following functions EXCEPT: a. providing energy b. aiding in immune function c. promoting bowel health d. providing cell structure
c. promoting bowel health
Which of the following population groups is at increased risk of PEM? a. college athletes b. obese individuals c. the elderly d. adolescents
c. the elderly
a process involved in the synthesis of nonessential amino acids is called __________. a. ketogenesis b. gluconeogenesis c. transamination d. supplementation
c. transamination
Which of the following nutrients would most likely be low in a vegan diet? a. vitamin C b. thiamin c. vitamin B-12 d. dietary fiber
c. vitamin B-12
the muscle wasting in the body due to the conversion of amino acids into glucose
cachexia
minute blood vessels, 1 cell thick, that create a junction between arterial and venous circulation. Gas and nutrient exchange occurs here between body cells and the blood
capillary beds
what are the major sources of fuel for cells
carbohydrates and fats
amino acid without the amino group
carbon skeleton
The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is derived by multiplying a food's __________________ by the food's ___________________
chemical score; digestibility
__________ triggers the release of the hormones secretin and CCK
chyme
specific sequence of 3 nucleotide units within DNA that codes particular amino acids needed for protein synthesis
codon
protein synthesis takes place in the __________ of the cell
cytosol
The complementary mRNA nucleotide ofguanine is _________ and the complementary tRNA is ___________
cytsosine; guanine
Which of the following foods is a common cause of food allergies? a. peanuts b. eggs c. shellfish d. all of the above
d. all of the above
Which of the following is a rich source of protein? a. citrus fruits b. dark, leafy greens c. enriched grains d. barbequed chicken
d. barbequed chicken
Which of the following is NOT a means of determining the protein quality of a food a. biological value b. chemical score c. protein efficiency ratio d.complementary score
d. complementary score
losing an amino group from an amino acid without transferring it to a carbon skeleton is called ______________.
deamination
high-protein diets lead to increased urine output which in turn poses a risk for ____________
dehydration
nonessential amino acids are also called ____________ amino acids
dispensable
fluid buildup in the interstitial fluid
edema
what is the chief factor that governs the quality of a food protein?
essential amino acid content
amino acids that the human body cannot synthesize in sufficient amounts or at all and therefore must be included in the diet
essential amino acids
The complementary mRNA nucleotide of cytosine is _________ and the complementary tRNA is ___________
guanine; cytosine
proteins in the blood that are responsible for identifying and neutralizing antigens as well as pathogens that bind specifically to antigens
immunoglobulins
a high-protein diet may _________ calcium loss in urine
increase
____________ amino acid is another term for essential amino acid
indispensable
What hormones stimulate positive protein balance?
insulin, growth hormone, testosterone
condition occurring primarily I young children who have an existing disease and consume a marginal amount of energy and severely insufficient protein. It results in edema, poor growth, weakness, and in increased susceptibility to further infection and disease
kwashiorkor
the essential amino acid in lowest concentration in a food or diet relative to body needs and limits the amount of protein a body can synthesize
limiting amino acid
What are the limiting amino acids in grains?
lysine
What are the limiting amino acids in nuts and seeds?
lysine
synthesis of polypeptide chains by the ribosome according to information contained in strands of messenger RNA (mRNA)
mRNA translation
condition that results from a severe deficit of energy and protein, which causes extreme loss of fat stores, muscle mass, and body weight
marasmus
requires large amounts of calories and proteins to treat
marasmus
What are the primary limiting amino acids in legumes?
methionine and tryptophan
______________________ occurs during: -inadequate intake of protein -inadequate energy intake -conditions such as fevers, burns, and infections -bed rest -deficiency of amino acids
negative nitrogen balance
amino acids are unique among the energy-yielding nutrients because they contain __________
nitrogen
______________________ occurs during: -healthy adult meeting protein and energy needs
nitrogen equilibrium
should amino acids be taken as supplements?
no
amino acids that the human body can synthesize in sufficient amounts
nonessential amino acids
__________ is a major stomach enzyme used for digesting proteins
pepsin
What are the essential amino acids?
phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, lysine
amount of a nutrient found within the body that can be easily mobilized when needed
pool
______________________ occurs during: -growth -pregnancy -recovery stage after illness/injury
positive nitrogen balance
the sum of protein breakdown and synthesis
protein turnover
condition resulting from insufficient amounts of energy and protein, which eventually result in body wasting and an increased susceptibility to infection and disease
protein-energy malnutrition (PEM)
intact proteins are __________ absorbed from the digestive tract
rarely
occurs because of defects in the structure of the protein chains of hemoglobin, a protein that carries oxygen in red blood cells
sickle cell disease
the ________ takes amino acids to the ribosomes as needed during protein synthesis
tRNA
transferring an amino group from 1 amino acid to a carbon skeleton
transamination
Hospitalized patients recovering from illness or trauma usually need additional protein to attain positive nitrogen balance: true/false
true
Many children with kwashiorkor maintain some muscle and subcutaneous fat: true/false
true
a person that has the genetic PKU requires __________ to be a conditionally essential amino acid
tyrosine
what amino acid is conditionally essential?
tyrosine
The complementary mRNA nucleotide of adenine is _________ and the complementary tRNA is ___________
uracil; adenine
nitrogenous waste product of protein metabolism and the major source of nitrogen in the urine; chemically depicted as this:
urea
what are reasons for consuming a vegetarian diet?
various philosophies, science, religious views, ecological
The most common nutritional concerns for infants and children following vegetarian and vegan diets are:
vitamin D, iron, vitamin B-12
process of forming messenger RNA (mRNA) from a portion of DNA
DNA transcription