nutrition chap 6

essential amino acids

cannot be synthesized at all by the body or cannot be synthesized in amounts sufficient to meet physiological need. must be obtained from food.

conditionally essential amino acids

an amino acid that is normally nonessential but must be supplied by the diet in special circumstances when the need for it exceeds the body's ability to produce it

limiting amino acid

an essential amino acid that is present in dietary protein in an insufficient amount, thereby limiting the body's ability to build protein. proteins make do with what they have, and if there isn't enough amino acid to build a particular protein then it will be dismantled so the other amino acids can be put to better use. limiting amino acid can cause protein malnutrition problems

amino acid recycling and protein turnover

-Cells recycle amino acids by taking proteins apart, releasing amino acids which can be used by the cell: To build new working proteins like enzymes or structure proteins. To build nitrogen-containing compounds. To be used for energy. -this recycling program also allows for an emergency fund of amino acids in times of fuel, glucose, or protein deprivation. -example: digestive enzymes are digested and absorbed by small intestine cells. these cells can send these amino acids to the liver or can use them for it's own needs.

protein quality factors

-DRI recommendations assume a normal mixed diet of animal and plant products will be consumed -Quality of proteins should be carefully considered if the food supplies are very limited, affecting calories, nutrients, and protein available -Complete (high-quality) proteins - Almost all animal products are considered to be complete protein sources because they contain all of the 9 essential amino acids. Almost all animal products contain all 20 of the amino acids. This means animal products are also sources of the conditionally essential amino acids. -Incomplete (low-quality) proteins - All plant products (including soy products) are considered to be incomplete protein sources; because they are missing one or more of the essential amino acids. Fruits and oils are not considered to be sources of any type of protein. There are only tiny insignificant traces of protein in fruit. There is no protein at all in oils

Focusing on amino acids and proteins, describe phenylketonuria (Ch. 3 and 6), celiac disease, and food allergy responses (Ch. 4 and 6). List possible strategies to minimize health risks of each concern.

-Phenylketonuria (PKU) - unable to produce enzymes needed to change phenylalanine to tyrosine. -celiac disease - autoimmune disorder affecting the small intestines triggered by exposure to gluten. the small intestinal tract becomes inflamed, villi and microvilli damaged. this severely limits absorption of protein and other foods. help this by avoiding all gluten -food allergy responses - very similar to celiac disease, but without the antibodies that diagnose celiac. help this by avoiding all gluten

absorption site competition

-The small intestine has specific areas along its length where only certain types of amino acids (based upon their side chains) are accepted for absorption. If the amino acid misses its section of the small intestine where it should be absorbed, that amino acid will travel on to the colon and out with fecal material -competition for absorption sites results in absorbing excessive amounts of some amino acids while blocking essential and/or conditionally essential amino acids. -active transport sites fill with the more favored amino acids which prevent other amino acids from getting absorbed in the section. this can lead to limiting amino acid problems, as well as the liver converting the excess amino acids into glucose, glycogen, and/or fat for potential energy use. This is considered "wasting" amino acids

Describe the structure of amino acids, name their bonds, and list the functions of proteins in the body

-amino acids contain an acid group, a central carbon, amine group, and side chain (this is what makes each amino acid unique) -essential amino acids - histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine -nonessential amino acids - alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine -protein functions - acid-base balance, antibodies, blood clotting, energy and glucose, enzymes, fluid and electrolyte balance, gene expression, hormones, structure and movement, transport system

Describe the protein digestion process, include denaturation; absorption and its issues, and initial transport of proteins into the body. List uses of excess amino acids and name the two energy storage forms for excess amino acids.

-denaturation - the irreversible change in a protein's folded shape brought about by heat, acids, bases, alcohol, salts of heavy metals, or other agents -digestion process - begins in the stomach, hydrochloric acid denatures dietary protein, this activates pepsin which is the stomach's protein digesting enzyme and breaks protein down into polypeptides. in small intestine, pancreatic juices containing digestive enzymes and bicarbonate ions neutralize acid from stomach and inactivate pepsin. this juice provides protease which further digests protein. amino acids that aren't absorbed are lost in fecal matter, however almost all protein is digested and absorbed

Distinguish among the omnivore diet and the diets of lacto-vegetarians, lacto-ovo-vegetarians, ovo-vegetarians, and vegans. Discuss the possible advantages / disadvantages of these diets.

-lacto-vegetarian - vegetarian that includes dairy, no eggs -lacto-ovo-vegetarian - no meat, includes eggs and dairy -ovo-vegetarian- vegetarian, includes eggs, no dairy -vegan - only foods from plant sources, no eggs or dairy. -pros and cons of omnivore - great growth through age 25-26, faster immune responses. can lead to inadequate amounts of certain nutrients, saturated fats and cholesterol are heavy in meat, often more processed, additives -pros and cons vegetarian- controls weight really well, normal blood pressure, reduced risk of cancers and constipation. can cause loss of nutrients by too much fiber, unintentional weight loss, can hurt growth especially during pregnancy, slower immune response

nitrogen based states

-nitrogen balance - amount of nitrogen consumed with the amount excreted in a given time -positive nitrogen balance - a growing child, person building muscle, and pregnant women, are retaining more nitrogen than they are excreting. they need the extra nitrogen to support them during this time of growth. -negative nitrogen balance - elderly, illness, surgery patients are losing more nitrogen than they are taking in. occurs when muscle or other protein tissues are broken down due to messengers in the body signaling the break down of less vital proteins in blood, skin and muscle

Distinguish among protein-energy deficiency states, include initial signs and symptoms of protein-energy deficiency, kwashiorkor, and marasmus.

-protein energy malnutrition - inadequate calories and/or protein. very serious in children but can occur at any stage in life. -kwashiorkor - growth for children is disrupted, loss of appetite, stomach begins shrinking and muscle loss, but an edema forms in the abdomen (excess fluid between the tissues). enlarged fatty liver, skin lesions, hair becomes dry and brittle, high risk of infection, loss of hope. -marasmus - growth for children is disrupted, appetite is normal or slightly impaired, severe deprivation of nutrients, high risk for infections, severe weight loss fat loss and muscle loss, no edema or fatty liver, hair becomes dry and brittle, skin is dry and thin, anxiety -treatment - address dehydration, fluid and nutrient imbalances; provide nutritionally dense calories and high quality protein to restore tissues and body structures; gradually transition to foods and physical activity

Evaluate the use of protein bars, shakes, and supplements, and amino acid supplements

-protein supplements do not improve performance and they aren't effective for weight loss. amino acid supplements don't work because the body is designed to work with whole proteins, and there is no regulation in levels of amino acids. -excess protein and amino acids can lead to weight gain. - can cause limiting of amino acids and competition for absorption sites

denaturation

-the irreversible change in a protein's folded shape brought about by heat, acids, bases, alcohol, salts of heavy metals, or other agents -Denaturation: the alteration (unfolding or uncoiling) of a protein's shape, which changes the structure and function of the protein -Examples of substances used with foods which commonly denature proteins are: Heat - baking, grilling, roasting, stewing, etc. Acids - vinegar, citrus fruits/juices, tomatoes Bases (alkaline) - baking powder or soda Alcohol - beer, liquor, wine as ingredients and as marinates to soak meats in prior to cooking -Other substances which can denature proteins: Radiation. Poisons such as the salts of heavy metals (such as cadmium, lead, mercury, silver, etc.)

Identify the factors considered in establishment of the protein DRI and calculate both the protein DRI and the safe protein intake range based on body weight.

Adults = 0.8-1.6 // strength and speed Athletes = 1.2-1.7 // endurance athletes = 1.2-1.4 10-35% of calories should come from protein. DRI recommends a normal mixed diet of animal and plant protein

incomplete protein

All plant products (including soy products) are considered to be incomplete protein sources; because they are missing one or more of the essential amino acids. -Fruits and oils are not considered to be sources of any type of protein. There are only tiny insignificant traces of protein in fruit. There is no protein at all in oils.

complete protein

Almost all animal products are considered to be complete protein sources because they contain all of the 9 essential amino acids, and most also contain all 20 of the amino acids. This means animal products are also sources of the conditionally essential amino acids.

wasting amino acids

The absorption of excessive amounts of the more "favored" amino acids results in the liver converting the excess amino acids into glucose, glycogen, and/or fat for potential energy use. This is considered "wasting" amino acids. -partially completed proteins are not held for completion at a later time, rather they are dismantled so amino acids can be made available to other proteins. if they aren't used soon, the amine groups are removed and excreted, and the needs that prompted the creation of that particular protein will not be met -conditions that cause wasting - Inadequate amount of energy available for body, Less than 130 grams of carbohydrate consumed, Excessive amount of protein (includes excessive amounts of amino acids) consumed, Too few essential amino acids consumed -preventing waste of amino acids - Consume an diet containing adequate calories and amounts of carb, fat, good quality protein, vitamins, minerals, and water

Using dietary recommendations, identify dietary sources of proteins. Determine the type of protein dietary sources that are best digested and absorbed (consider complete and incomplete proteins; animal or plant source; and if it is cooked or raw).

animal proteins provide most easily digestible proteins (over 90%), legumes (80-90%), grains and veggies are variable (70-90%). cooked with moist heat makes it more digestible

amino acids

building blocks of proteins. each has an amine group at one end, an acid group at the other, and a distinctive side chain. there are 20 unique forms of amino acids, 9 essential and 11 nonessential.

proteins

compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain. Some amino acids also contain sulfur atoms. consist of some combination of 20 unique amino acids.

Explain complementary proteins and apply this principle to diet planning.

incomplete plant protein sources work together to supply missing amino acids, thereby complementing one another. by doing this, you can be sure you are getting sufficient amounts and a good variety of amino acids. table shows you should pick foods from two or more categories of: grains, legumes, veggies, seeds/nuts

urea

the principal nitrogen-excretion product of protein metabolism; generated mostly by removal of amine groups from unneeded amino acids or from amino acids being sacrificed for energy. Two ammonia fragments are combined with carbon dioxide to form urea.

List health concerns seen with excess protein intake.

weight loss, weight gain, heart disease, kidney problems, adult bone loss, cancer

ammonia

when an amino acid if used for energy, it must have its amine (NH2) group removed. the amine group is sent to the liver, where it is converted to ammonia (NH3). ammonia is very toxic to cells in the body, so the liver quickly converts ammonia into urea. if the liver is damaged or diseased and cannot do this, excessive amounts of ammonia can build up in the blood, which can cause coma and death