Week 3 Macro-nutrients Handout Flashcards
what are macronutrients
nutrients required in large amounts. water, carbs, lipids, proteins
what are micronutrients
nutrients needed in small amounts. vitamins and minerals
what is RDA?
recommended daily allowance
what is the RDA for proteins?
0.8 g/kg body weight/day
describe the process of AA absorption from kidneys?
an active process that requires Na. absorbed in small intestine and transported to liver via portal vein
where is the amino acid pool located?
ECM
there are 20 AA, but not 20 AA transporters (into blood), what does this mean?
some AA share a transporter, this can create competition
the fact that AA compete for transporteres suggests…
that even if the dietary intake of AA is met, an AA imbalance could still occur
what an AA reaches the AA pool what are its fates (2)?
anabolism: used in protein synthesis or synthesis of other non-essential AA
carabolism: broken down into carbon skeleton and enter TCA cylce to produce energy
what are the essential AA?
PVT. TIM HALL
Phe, Val, Threonine, Tryp, Iso, Met, His, Arg** Leu, Lys
**Arg is no longer considered essential
A complete protein will…
maintain life and normal growth as a sole protein source
a partially complete protein will….
maintain life but not growth
an incomplete protein will…
not maintain life
what is chemical score? how is it determined
essential AA of a test protein are compared to that of egg protein (high quality standard) to determine which AA gives the largest % deficiency. CS=(mg AA/g test protein)/(mg of essential AA/g egg protein)x100. gives the limiting essential AA
what is the biological value of protein?
the measure of the percentage of the absorbed AA retained for protein synthesis (accounts for AA lost in urine and feces)
what is the sparing effect?
some nutrients can reduce (spare) the requirements of another by fulfilling one of the demands of the second nutrient. Ex Cys can spare Met by providing a sulfur. Carbs spare the need for glucogenic AA
what are complementary proteins?
two poor quality proteins that differ in the limiting essential AA will form a higher quality and more adequate protein when mixed together
what is net protein utilizaton?
similar to BV but neglects absorption
what is the protein efficiency ratio?
weight gain in animal/weight of protein ingested during that period of time
what is digestibility of protein?
the percentage of food N absorbed (food N eaten-N lost in feces)/food eaten
how do you measure Protein Digestibility corrected AA score (PDCAAS)
this measures the limiting AA (like Chemical score) but bases the calc off the requirements of a 2-5 year old instead of an egg.
AAS= mg essential AA in 1 g test/mg EAA in 1 g protein requirement
PDCAAS= lowest scoring AAS *true protein digestibility
what is PEM?
protein-energy malnutrition resulting from protein deficient diets
what are two classic PEM diseases.
kwashiorkor disease and marasmus
what is kwashiorkor disease? cause? seen? symptoms
a severe protein deficiency disorder. caused by a lack a protein. seen in poorer countries where babies are abruptly weened off breast milk. edema, mental apathy, muscle wasting
what is marasmus?
a protein-calorie malnutriton that is less severe than kwashiorkor (lower mortality). usually occurs in first year of life with a more starved appearance
what is an available carb?
a carb (starch) that can be digested and absorbed and used in our bodies
what is an unavailable carb?
carbs that we cant absorb but that aid in elimination (insoluble:cellulose and soluble:pectin)
what are dietary fibers? (what are they)
what remain after breakdown in the digestive tract. Unavailable carbs and non-carb polymers (lignin)
what is crude fiber?
what remains of dietart fiber after acid and alkaline digestion of food. insoluble unavailable and non-carb polymer
what are some issues arising from extremely low carb intak?
ketosis, loss of cations, dehydration, protein break down
what is added fiber?
purified undigestible carbs added back to food for beneficial physiological effects
what are 5 benefits to fiber in the diet?
reduce incidence of some diseases (hemorrhoids, hyperlipidemia NOT Colon cancer), promote weight loss by giving a full sensation, prevents constipation, facilitates removal of cholesterol, promotes glycemic control in diabetes
what are exchange groups?
total of six groups of food. within each group there are listings of foods that have the same nutrient composition
what is the glycemic index?
tells you how much a set amount of a certain food will raise blood glucose. the higher the number the larger the increase
what is glycemic load?
tells you how much the total amount of a food will raise raise blood sugar. total glycemic response, not just for a set amount of the food
what are the three types of fat in our diets?
glycerides, phospholipids, sterols
what are the 4 fxns of trigylcerides
energy, building material (can be converted to other lipids), protection, insulation
what are the main functions of phospholipids and cholesterol? 2
form cell membranes, building material
what are the essential FAs? why?
linoleic acid (omega 6) and linolenic (omega 3). becuase we cant introduce double bonds at omega six or omega 3
what are some symptoms of essential fatty acid deficiency? 3
dermatitis, alopecia, thrombocytopenia
what can treat EFA deficiency? 3, which are best?
linoleic acid (omega-6)> linolenic acid (omega-3)> arachidonic acid (provide the missing FA..)
unsaturated FAs are most commonly…
cis
what are some characterisitcs of trans FAs compared to cis
trans: higher MP, increases LDL/HDL ratio, increase shelf life (only trans fat decrease HDL cholesterol level, trans and saturated both increase LDL)
what are the benefits of omega-3 FAs? 4
lower risk/treat coronary heart disease, lower LDL, possible increase HDL, prevent clotting
