Chapter 7 Flashcards
Protein
large, complex organic molecules made up of amino acids (contains Nitrogen)
Antibodies
Protein makes these immune molecules that tag invading organisms for destruction by the immune system
Major Functions of Protein
- build new cells
- component of hardened structures (hair and nails)
- enzymes
- lubricants
- clotting components
- antibodies
- compounds that maintain pH and fluid
- transporters
- energy source
edema
accumulation of fluid in tissues; swelling
results from starvation
hair protein
collagen
nail protein
keratin
blood protein that controls fluid
albumin
pH of functioning blood and tissue fluids
7.35 to 7.45
amino acids
nitrogen-containing chemical units that constitute proteins
amino
portion of an amino acid that contains nitrogen
R group (side chain)
part of an amino acid that determines its physical and chemical properties
components of an amino acid
amino
R group
carboxylic acid
essential amino acids
& how many
amino acids the body cannot make or cannot make enough of to meet its needs (9/20)
nonessential amino acids
& how many
group of amino acids that the body can make (11/20)
conditionally essential
amino acids that are normally nonessential but become essential under certain conditions
precursors and derivatives of amino acids
precursor (amino acid used) used to make non-protein nitrogen-containing compounds
- trytophan makes serotonin
- tyrosine makes eoineohrine
DNA
hereditary material that provides instructions for making proteins
gene
portion of DNA that codes for a protein
chemical attraction that connects two amino acids together
peptide bond
polypeptides
proteins comprised of 50 or more amino acids
-most naturally occurring proteins
how are proteins made?
cells assemble 20 amino acids in specific sequence according to info from DNA
primary structure protein
basic structure of protein; a linear chain of amino acids linked by peptide bonds
secondary structure protein
coiling of a polypeptide chain
tertiary structure protien
three-dimensional, twisted structure of a polypeptide chain that includes interactions between various amino acid groups in the chain
quaternary structure protein
structure of protein that is comprised of two or more polypeptide chains arranged together in a complex manner
-example: hemoglobin
sickle cell anemia
inherited form of anemia, abnormal blood cells that cant carry oxygen as well.
denaturation
altering a protein’s natural shape and function by exposing it to conditions such as heat, acids, and physical agitation
high-quality protein
dietary proteins that are complete and well-digested, absorbed, and used by the body
complete protein
dietary proteins that contain an adequate proportion of each of the nine essential amino acids
low-quality proteins
dietary proteins that are incomplete and have lower digestibility and bioavailability
imcomplete proteins
dietary proteins that contain inadequate amounts of one or more of the essential amino acids
limiting amino acid
essential amino acid found in the lowest concentration in an incomplete protein
most plant sources are not complete proteins. WHat are the exceptions?
Quinoa and soy protein
Where does protein digestion start?
stomach
Steps in Protein Digestion
HCl denatures proteins and converts pepsinogen to active pepsin, which initiates enzymatic digestion of proteins into smaller polypeptides.
how does the pancreas aid in protein digestion?
secretes trypsin and chymotrypsin to break down the polypeptides that enter the small intestine
What happens after digesting of proteins?
short peptides and amino acids are transported to absorptive cells, the peptides are broken into amino acids, which move into the capillary of the villus.
travel to liver then rest of body
protein turnover
cellular process of breaking down proteins and recycling their amino acids
amino acids that are not incorporated into proteins become part of s small amino acid pool, which serves as a _______?
an endogenous (internal) source of nitrogen.
the human body gets how much of its amino acids from endogenous and exogenous sources.
2/3 from endogenous
1/3 from exogenous (diet)
Deamination
removal of the nitrogen-containing group from an amino acid
what the result of deamination
the amino acid becomes a carbon skeleton
Transamination
transfer of the nitrogen-containing group from an unneeded amino acid to a carbon skeleton to form an amino acid
creatinine
nitrogen-containing waste produced by muscles
where do extra amino acids go if you eat too much protein?
undergo deamination, NH2 is transported to liver as glutamate, forming ammonia.
liver converts ammonia to urea.
blood urea nitrogen (BUN)
measure of the concentration of urea in blood ( blood test that assesses kidney function)
Normal values fro BUN
6 to 20 mg/dl
urine urea nitrogen (UUN)
measure of the concentration of urea in urine
- normal values 12 to 20 g in 24 hrs
- measures protein intake
nitrogen balance (equilibrium)
balancing nitrogen intake with nitrogen losses
ntrogen lose comes from?
urinary elimination
nail and hair grow
shed the out layer of cells in intestinal tract
positive nitrogen balance
state in which the body retains more nitrogen than it loses
- periods of rapid growth
- recovering from injury or illness
- weight resistance training
negative nitrogen balance
state in which the body loses more nitrogen than it retains
- starvation
- serious illness
- severe injury
protein complementation
combining certain plant foods to provide all essential amino acids
protein values for average human
0.8 g/kg body weight
10 to 35% of calories protein
protein-energy malnutrition (PEM)
malnutrition that occurs when the diet lacks sufficient protein and energy
kwashiorkor
form of undernutrition that results from consuming adequate energy and insufficient high-quality, complete protein
marasmic kwashiorkor
form of undernutrition that results in a child with kwashiorkor who then starts to not consume enough energy; characterized by edema and wasting
marasmus
form of undernutrition that results from starvation; diet lacks energy and nutrients
anaphylaxis
serious, life-threatening allergic reaction to food, an insect bite, a drug, or another substance such as latex
anaphylactic shock
an extreme drop in blood pressure
celiac disease
autoimmune disorder in which antibodies made against gluten react with intestinal villi; results in damage to the small intestine and poor absorption of nutrients
gluten
protein found in many grain-based food products
food provocation test (FPT)
clinical elimination-challenge test used to diagnose food intolerances
food intolerances
conditions characterized by unpleasant physical reactions following consumption of certain foods
FODMAPs
types of carbohydrates that are difficult for some people to digest and absorb
-have reduced ability to absorb the frictose from bacterially digested fructan. results in bloating, gas, diarrhea.
phenylketonuria (PKU)
genetic metabolic disorder characterized by the inability to convert the amino acid phenylalanine into tyrosine, resulting in accumulation of phenylalanine
-all infants get tested from blood at birth
nutritional genomics
study of nutrigenomics and nutrigenetics
nutrigenomics
study of how nutrients affect the expression of a person’s genome
nutrigenetics
study of how inherited genetic variations influence the body’s responses to specific nutrients and nutrient combinations.
inborn errors of metabolism
conditions that occur when genes undergo mutations that disrupt metabolism of specific nutrients (pku)
