Nutrition Chapter 6: Proteins and Amino Acids

collagen

a ropelike, fibrous protein that is the most abundant protein in your body

Soy, which is from a plant, is not as good a source of dietary protein as fish. True or False?

False Soy foods contain complete proteins, as do fish, so they are both good sources of protein.

complete protein

all essential amino acids, plus some nonessential amino acids - Sources: soy, quinoa, and animal protein

A plant-based diet can be rich in high-fiber, nutrient dense foods like fruits and vegetables, which naturally results in lower intakes of ________.

saturated fat and cholesterol

Which of the following is a source of complete protein? Soy milk Pasta Peanut butter Kidney beans

soy milk Soy foods such as soy milk provide all the essential amino acids that you need, along with some nonessential amino acids, and thus are a source of complete protein. Kidney beans, peanut butter, and pasta are missing adequate amounts of some essential amino acids.

Kwashiorkor is a type of protein-energy malnutrition that develops when _____.

there is a severe deficiency of protein in the diet but an adequate intake of energy Kwashiorkor develops when there is a severe deficiency of protein in the diet but an adequate intake of energy. With protein deficiency, fluid accumulates in the spaces surrounding the cells, causing edema (swelling) in the legs, feet, and abdomen. Muscle proteins are broken down to generate the amino acids needed to synthesize critical functional proteins. Animal protein in the diet is not necessary, because people can meet their protein needs from a combination of plant proteins, such as soy and other legumes, grains, and vegetables, as part of a well-balanced diet. Marasmus is a condition in which there is a severe deficiency of energy intake, including protein intake.

coenzyme

substances needed by enzymes to perform many chemical reactions in your body. Many vitamins act as coenzymes.

sickle-cell anemia

A blood disorder caused by a genetic defect in the development of hemoglobin. It causes the red blood cells to distort into a sickle shape and can damage organs and tissues.

Too much protein affects levels of what mineral in the body, resulting in issues with kidney stones and osteoporosis?

Calcium

Charlie is a 22-year-old male nonathlete who weighs 70 kilograms. How much protein should he consume daily?

56 grams Charlie should consume 56 grams of protein daily. The current RDA for protein is based on age and weight. Nonathletic adults age 19 and older should consume 0.8 gram (g) of protein for each kilogram (kg) of body weight. Since Charlie weighs 70 kg, he should consume 70 kg × 0.8 g, or 56 grams of protein a day.

There are ___________ essential amino acids that cannot be made by the body.

9 There are 9 essential amino acids that cannot be made in the body, so you must obtain these from foods.

Which of the following statements is FALSE for nitrogen equilibrium? A healthy adult is typically in nitrogen equilibrium Someone experiencing medical trauma is likely to be in negative nitrogen balance Pregnant women tend to be in positive nitrogen balance Adolescents are usually in negative nitrogen balance

Adolescents are usually in negative nitrogen balance

nitrogen balance

Amount of nitrogen consumed (in dietary protein) = amount excreted (in urine)

What function as biological catalysts that speed up reactions in the body?

Enzymes

Which type of protein denaturation occurs when someone has a high fever?

Heat denaturation

Which of the following is NOT part of an amino acid? Acid group Hydroxyl group Side chain Amine group

Hydroxyl group

_______ would be able to enjoy an egg omelet.

Lacto-ovo-vegetarians

_______ consume grains, vegetables, fruits, legumes, seeds, nuts, dairy foods, and eggs, but do not consume meat, fish, and poultry.

Semivegetarians

Which organ of the digestive system converts proteins to glucose?

The liver

immunity

The state of having built up antibodies to a particular foreign substance so that when particles of the substance enter the body, they are destroyed by the antibodies.

How do dried beans contribute positively to one's diet?

They are an excellent source of both protein and fiber

edema

accumulation of excess fluid in the spaces surrounding your cells, which causes swelling of the body tissue

proteins

compounds in your body that consist of numerous amino acids and are found in all living cells

RNA

molecule that carries out the orders of DNA (ribonucleic acid)

gene

segment of DNA that codes for a specific protein

estrogen

the hormone responsible for female sex characteristics

urea

a nitrogen-containing waste product that is excreted in urine

transfer RNA (tRNA)

a type of RNA that collects the amino acids within the cell that are needed to make a specific protein

messenger RNA (mRNA)

a type of RNA that copies the genetic information encoded in DNA and carries it out of the nucleus of the cell to synthesize the protein

isoflavones

naturally occurring phytoestrogens, or weak plant estrogens, that function in a similar fashion to the hormone estrogen in the human body

incomplete protein

low in one or more essential amino acids - Sources: plant foods

What is the correct sequence of protein synthesis?

mRNA, ribosome, tRNA, chain of amino acids, complete protein

Complete protein is found abundantly in _____.

meat A complete protein is a protein that provides all the essential amino acids that a body needs, along with some nonessential amino acids. Complete proteins are found abundantly in animal sources, such as meat, fish, and poultry. Soy protein is also a complete protein. While there is some protein in vegetables and in whole grains, this protein is considered incomplete because it is low or deficient in at least one of the essential amino acids. Fats do not contain protein.

antibodies

proteins made by your body to bind to and neutralize foreign invaders, such as harmful bacteria, fungi, and viruses, as part of the body's immune response.

Which of the following will not denature a protein? refrigerating milk grilling a chicken breast frying an egg marinating a steak in red wine

refrigerating milk Refrigerating milk does not alter the bonds between the amino acid side chains in the milk proteins, and so it does not denature the proteins. Heating a protein (such as when grilling a chicken breast or frying an egg) and adding acid to it (such as marinating a steak in acidic red wine) will denature proteins by altering the bonds.

marasmus

severe deficiency of calories - Signs: emaciation, lack of growth, loss of fat stores

kwashiorkor

severe deficiency of dietary protein - Signs: edema, muscle loss, skin rashes, hair changes, water and electrolyte imbalances - Seen in children weaned to low-protein cereals

transport proteins

shuttle oxygen, waste products, lipids, some vitamins, and sodium and potassium through your blood and into and out of cells through cell membranes

After a person consumes a glass of soy milk, where does the majority of the digestion and absorption of the protein occur?

small intestine After a meal, the majority of protein digestion and absorption occurs in the small intestine. Chemical digestion of protein begins after chewed food enters the stomach. Hydrochloric acid breaks down the bonds of protein strands and activates pepsin, a digestive enzyme, which breaks the protein into shorter polypeptide strands. In the small intestine, proteases further break down protein strands into tripeptides and dipeptides, as well as some amino acids. The protein remnants are then absorbed into the cells of the small intestine lining, where the remaining tripeptides and dipeptides are broken down into single amino acids that are then released into the bloodstream. In the mouth, mechanical digestion of protein begins with chewing, tearing, and mixing of food with salivary juices to form a bolus, or soft mass of chewed food. The pancreas produces enzymes, including proteases, that are released into the small intestine via the pancreatic duct.

denaturation

the alteration (unfolding) of a protein's shape, which changes the structure and function of the protein

limiting amino acid

the amino acid that is in the shortest supply in an incomplete protein

A protein's shape, and therefore its function in your body, is determined by the interactions of ___________ with each other and their environment.

the amino acids in the protein The interactions of the amino acids with each other and with their environment determine the shape, and thus the function, of the proteins in your body.

fluid balance

the equal distribution of water throughout your body and within and between cells

connective tissue

the most abundant tissue type in the body; made up primarily of collagen, it supports and connects body parts as well as providing protection and insulation

essential amino acid

the nine amino acids that the body cannot synthesize; they must be obtained through dietary sources

amine group

the nitrogen-containing part (NH2) of an amino acid

amino acid profile

the types and amounts of amino acids (essential, nonessential, or both) that the protein contains.

Kwashiorkor is a type of PEM that develops when

there is a severe deficiency of protein in the diet but an adequate amount of calories. Kwashiorkor occurs when protein is deficient in the diet even though calories may be adequate. Marasmus occurs when calories are inadequate in a person's diet and thus he or she is starving. Protein from animal sources is not necessary because people can meet their protein needs from a combination of plant proteins, such as soy, legumes, grains, and vegetables, as part of a well-balanced diet.

Protein plays many important roles in your body. Which role does it NOT play in your body? Transporting fat and cholesterol through your blood Helping you absorb fat-soluble vitamins in the diet Helping you fight the flu Allowing you to walk, run, sit, and lie down

Helping you absorb fat-soluble vitamins in the diet You need adequate amounts of protein to fight infections such as the flu, to provide structural and mechanical support when you're moving or lying down, and to transport substances such as fat and cholesterol through your blood. Protein does not help with the absorption of fat-soluble vitamins in your body.

vegetarian

A person who doesn't eat meat, fish, or poultry or (sometimes) foods made from these animal sources.

________ enhances the absorption of iron in plant foods.

Vitamin C

digestibility

a food's capacity to be broken down so that it can be absorbed

protein-energy malnutrition (PEM)

a lack of sufficient dietary protein and/or calories

amino acid pools

a limited supply of amino acids stored in your blood and cells and used to build new proteins

precursor

a substance that is converted into or leads to the formation of another substance

nonessential amino acid

the 11 amino acids that the body can synthesize

acid group

the COOH group that is part of every amino acid; also called the carboxyl group

________ are great food sources for vegetarians to consume for protein.

Soybeans, quinoa, tofu, nuts, peanuts, legumes, and seeds

Brendan is a 20-year-old male. How much protein does he need daily?

0.80 gram per kilogram body weight. Individuals who are 19 years of age and older need 0.80 gram per kilogram body weight of protein daily.

You can digest the protein in pasta as easily as the protein in a chicken breast. True or False?

False Although both pasta and chicken can contribute to your daily protein needs, the protein in poultry is more easily digested than the protein found in grains.

Americans are eating more red meat than they were in the 1970s. True or False?

False Contrary to media headlines, Americans are eating less red meat than they were decades ago.

Protein bars are needed if you are very active. True or False?

False Even an extremely active person can easily meet his or her protein needs through a well-balanced diet.

Which of the following functions of protein in the body is INCORRECTLY paired? Transport of substances through blood: enzyme production Provide mechanical support: ligament production Maintain fluid balance: edema prevention Immune system: antibody production

Transport of substances through blood: enzyme production

The latest AMDR for protein is _____ of one's daily energy intake.

10 to 35 percent The AMDR for protein is 10 to 35 percent of one's daily energy intake. Currently, adults in the United States consume about 15 percent of their daily energy from protein, which falls within this range. Carbohydrates should comprise 45 to 65 percent of an individual's daily kcal intake, and fat should comprise 20 to 35 percent. Consuming these nutrient types in these ranges will ensure that energy and nutrient needs are met and will reduce the risk of developing chronic disease.

Proteins consist of a chain of some combination of ____ unique amino acids.

20 Proteins consist of a chain of some combination of 20 unique amino acids, and they are classified according to the number of amino acids in the chain. Each protein contains a chain of at least 50 amino acids, though proteins typically contain between 100 and 10,000 amino acids. When the chain contains fewer than 50 amino acids, it's called a peptide. Three amino acids joined together is called a tripeptide, and two amino acids joined together is called a dipeptide. There are nine amino acids that the body cannot make and which therefore must be obtained from foods. These are the essential amino acids. The remaining 11 amino acids are nonessential amino acids because they can be synthesized, or created, in the body. It is not essential to consume them in the diet.

How many amino acids are considered essential to consume in the diet?

9 Of the 20 unique amino acids found in protein, 9 are considered essential to consume in the diet, because the human body cannot make them. The remaining 11 amino acids are just as important to human health, but they are called nonessential amino acids because they can be synthesized, or created, in the body. It is not essential to consume them in the diet.

What do you call a peptide chain that is between 10 and 50 amino acids long?

A polypeptide

An acceptable main dish for a lacto-ovo-vegetarian would be _____. stir-fried tofu and vegetables over brown rice a cheese and broccoli omelet baked ziti with ricotta cheese, spinach, and tomato sauce

All options are correct All options are correct. Stir-fried tofu and vegetables over brown rice; a cheese and broccoli omelet; and baked ziti with ricotta cheese, spinach, and tomato sauce are all acceptable main dishes for a lacto-ovo-vegetarian. Lacto-ovo-vegetarians eat a predominantly plant-based diet that also includes dairy foods and eggs. They avoid meat, poultry, and fish.

What animal product is NOT considered a complete protein? Chicken, because it is missing methionine Gelatin, because it is missing tryptophan Beef, because it is missing valine Fish, because it is missing leucine

Gelatin, because it is missing tryptophan

DNA

The blueprint in cells that stores all genetic information. DNA remains in the nucleus of the cell and directs the synthesis of proteins.

"Flag sign" is when children have a streak of depigmented hair due to a severe protein deficiency. Why would their hair be affected by protein deficiency?

The body does not have sufficient protein to create melanin

peptide bonds

The bonds that connect amino acids, created when the acid group of one amino acid is joined with the nitrogen-containing amine group of another amino acid.

amino acid

The building blocks of protein. Amino acids contain carbon, hydrogen, oxygen, and nitrogen. All amino acids are composed of an acid group, an amine group, and a unique side group.

Eating too much protein-rich food may increase your risk of heart disease. True or False?

True A high-protein diet from animal foods is usually associated with high levels of artery-clogging saturated fat and low amounts of whole grains, fruits, and vegetables. This type of diet is not heart friendly and may raise your blood cholesterol.

Proteins increase satiety after a meal. True or False?

True Protein increases satiety, the feeling of fullness, after a meal more than either carbohydrates or fat.

Which of the following is NOT a situation that would result in an amino acid becoming conditionally essential? When there is illness present When inadequate enzymes are available When a baby is born prematurely When the protein denatures due to acid

When the protein denatures due to acid

The process that destroys the shape and activity of proteins when heat, acid, salts, or pressure is applied is known as ______.

denaturation The process that destroys the shape and activity of proteins when heat, acid, salts, or pressure is applied is known as denaturation. This process disrupts the bonds between the amino acid side chains, causing the protein to uncoil. A hard-boiled egg, whipped cream, and curdled milk are all examples of denaturation. Condensation is a chemical reaction by which smaller molecules join to form larger compounds and water is released as a byproduct. Hydrogenation is the process in which hydrogen is added to an unsaturated fatty acid to make it more saturated and solid at room temperature. Deamination is the process by which an amine group is stripped from an amino acid.

Which of the following sources of protein has the highest digestibility? pork spinach kidney beans peanuts

pork Pork has the greatest digestibility of these proteins. Protein quality is determined by its digestibility, or the body's ability to digest it, and by its amino acid composition. Generally, animal protein is about 99% digestible, while plant protein (including peanuts, beans, and spinach) is only 87% digestible. Some plant protein is protected in the plant's cell walls, which cannot be broken down by the human body. Therefore, some protein is unavailable for use and is excreted from the body. Cooking plant protein can help to break down the cell walls and make plant protein more digestible.

Which of the following is a source of complete protein? soy milk kidney beans peanut butter pasta

soy milk Soy milk is a source of complete protein. Although plant protein is typically not complete protein, soy is an exception. Soy foods, such as soy milk, provide all the essential amino acids a body needs, along with some nonessential amino acids, and thus are a source of complete protein. Protein from animal sources, such as meat, fish, and poultry, is typically complete protein, whereas protein from plant foods tends to be incomplete. Kidney beans, peanut butter, and pasta are missing adequate amounts of some essential amino acids.

catalysts

substances that aid and speed up reactions without being changed, damaged, or used up in the process

buffers

substances that help maintain the proper pH in a solution by attracting or donating hydrogen ions

enzymes

substances that speed up chemical reactions in your body

protein turnover

the continual process of degrading and synthesizing protein. When the daily amount of degraded protein is equivalent to the amount that is synthesized, you are in protein balance.

protein digestibility corrected amino acid score (PDCAAS)

- Measure of protein quality taking into account digestibility and amino acid profile - Basis of protein as percent Daily Value on food labels

protein quality

- The protein's digestibility - The protein's amino acid profile: the types and amounts of amino acids (essential, nonessential, or both) that the protein contains. - the more easily digested and more complete, the higher the quality

Vegetarian athletes are at a competitive disadvantage compared with nonvegetarian competitors. True or False?

False Vegetarian athletes can keep their competitive edge if they are consuming a well-balanced vegetarian diet.

Protein synthesis is directed by a compound in the cell nucleus called ___________.

deoxyribonucleic acid (DNA) Protein synthesis is directed by a compound in the cell nucleus called DNA. DNA stores genetic information as genes, segments of DNA that direct the production of proteins. Although DNA provides the code for proteins, it doesn't actually take part in the building. Therefore, other important molecules are needed. Messenger RNA transcribes the code from the DNA and brings it out of the nucleus and into the cell cytoplasm, to the ribosome. There, the code is translated into the "language" of amino acids. Specifically, transfer RNA brings specific amino acids to the ribosome for protein assembly.

Pescetarians consume _______.

fish and seafood

side chain

the side group of an amino acid that provides it with its unique qualities; also referred to as the R group

Most Americans are falling short of their protein needs. True or False?

False On average, most Americans are not only meeting their daily protein needs but are also surpassing them.

Which of the following will NOT denature a protein? Frying an egg Marinating a steak in red wine Grilling a chicken breast Refrigerating milk

Refrigerating milk Heat and acids will denature proteins. Refrigeration does not alter the bonds between the amino acid side chains and so does not denature proteins.

Proteins play important roles in the body, including _____. fighting off the flu and other infections transporting nutrients through the blood aiding in digestion

all options are correct All options are correct. Proteins are involved in most of the body's functions and life processes. They are necessary for survival. Adequate amounts of protein are needed to help fight off the flu and other infections. Antibodies are proteins that eliminate foreign invaders, such as disease-causing bacteria and viruses. Transport proteins transport nutrients through the blood. They shuttle oxygen, waste products, lipids, some vitamins, and sodium and potassium through the blood and into and out of cells through cell membranes. Proteins also make digestive enzymes that aid in digestion.

A healthy immune system depends on an adequate supply of proteins that bind to and neutralize harmful invaders. What are these proteins known as?

antibodies A healthy immune system depends on an adequate supply of antibodies. Antibodies are proteins made by the body to bind to and neutralize foreign invaders, such as harmful bacteria, fungi, and viruses, as part of its immune response. Enzymes are substances that act as catalysts and speed up chemical reactions. Buffers are substances that help maintain the proper pH in a solution by attracting or donating hydrogen ions. Transport proteins are proteins that carry lipids (fat and cholesterol), oxygen, waste products, and vitamins through the blood to various organs and tissues or that serve as channels to allow substances to pass through cell membranes.

hormones

protein or lipid based chemical substances that act as "messengers" in the body to initiate or direct actions or processes. Insulin, glucagon, and estrogen are examples of hormones.

An 8-ounce glass of low-fat chocolate milk contains 160 kilocalories (kcal) and 8 grams of protein. What percent of the kcal in the milk comes from protein?

20 percent An 8-ounce glass of low-fat chocolate milk that contains 160 kcal and 8 grams of protein has 20 percent of its kcal from protein. Recall that protein provides 4 kcal per gram. A food or beverage with 8 grams of protein contains 32 kcal from protein (8 grams of protein x 4 kcal/gram = 32 kcal). The protein percentage of total kcal is thus 20 percent (32 kcal from protein ÷ 160 total kcal = 0.20, or 20 percent).

A lacto-ovo-vegetarian is coming to your house for dinner. You need to make a meal that she will enjoy. Which would NOT be an acceptable entrée? A cheese and broccoli omelet Stir-fried tofu and vegetables over brown rice An anchovy pizza Baked ziti with ricotta cheese, spinach, and tomato sauce

An anchovy pizza Because a lacto-ovo-vegetarian avoids meat, poultry, and fish, the anchovy (fish) pizza would not be an acceptable dinner option. However, because lacto-ovo-vegetarians eat a predominantly plant-based diet with dairy foods and eggs, the tofu stir-fry, cheese omelet, and baked ziti are all fine.

Approximately one-half of your daily calories should come from protein. True or False?

False Proteins do play a vital role in your body, but a little can go a long way. For most healthy adults, less than one-fifth of their daily calories should come from dietary protein.

Why would iron levels possibly be too low for a person following a vegetarian diet?

It is more difficult to absorb the form of iron found in plants

________ do not eat eggs.

Lacto-vegetarians

How would you know if someone was suffering from kwashiorkor?

They would have edema, low muscle tone, and brittle hair

Your body can use protein as an energy source. True or False?

True However, burning proteins, rather than carbohydrates or fat, for energy is an inefficient way to use this precious nutrient.

What happens to the amino acids that are absorbed after the digestive process is complete? A limited supply of all amino acids remains in amino acid pools in the blood and inside the cells. Some amino acids are degraded and the nitrogen excreted in urine while the carbon, hydrogen, and oxygen remains are used for energy, or are stored as fat. Many amino acids are used to build and maintain body tissues, make new clotting proteins, enzymes, antibodies, neurotransmitters, and other products.

all options are correct All options are correct. After the digestive process is complete, absorbed amino acids are degraded, with the nitrogen converted to ammonia and then to urea and excreted in urine. The remnants are then used for energy, or are stored as fat. When the diet is too low in carbohydrates, amino acids are used to make glucose to supply energy to the brain. Surplus amino acids from excess dietary protein are stored predominantly as fat. A limited supply of all amino acids remains in amino acid pools in the blood and inside the cells. Because the body can't make the essential amino acids, the pools need to be constantly restocked. Amino acids are continually being removed from the amino acid pools to create proteins on demand. Many of the absorbed amino acids are used to build and maintain body tissues and functional chemicals such as enzymes and neurotransmitters.

What food can be eaten with brown rice to ensure all of the body's amino acid needs are met? black beans almonds tofu

all options are correct All options are correct. Eating black beans, almonds, or tofu with brown rice will ensure all of the body's amino acid needs are met. When incomplete proteins such as brown rice are coupled with modest amounts of animal proteins or soy, or are combined with other plant proteins that are rich in the incomplete protein's limiting amino acids, the incomplete protein becomes a complete protein.

Which of the following is a major function of protein in the human body? maintaining fluid balance growth and maintenance of new tissue synthesis of certain hormones

all options are correct All options are correct. Proteins are involved in most of the body's functions and life processes and are necessary for survival. A major function of protein in the human body is to maintain fluid balance. Proteins play a major role in ensuring that body fluids are evenly dispersed in the blood and inside and outside cells. Proteins are the body's building materials and are needed for the ongoing growth and maintenance of new tissue. Proteins are also needed for the synthesis of protein and amino acid hormones that direct specific activities. For example, the hormones insulin and glucagon regulate blood glucose level.

The part of the protein molecule that contains nitrogen is called the ________.

amine group The part of the protein molecule that contains nitrogen is called the amine group. In addition to the amine group (NH2), each amino acid that makes up a protein has an acid group (COOH), a side chain, a hydrogen atom, and a central carbon. All amino acids contain the same parts, and the side chain is what makes each amino acid different.

Limited amounts of surplus amino acids are stored in the body in _____.

amino acid pools Limited amounts of all the amino acids exist in amino acid pools in the blood and inside cells. They are not found in the stomach. The body uses amino acids from the amino acid pools to create protein when needed. Muscles contain protein but don't store surplus amino acids. Fat stores are the result of excess calories from carbohydrates, proteins, and/or fats.

Limited amounts of surplus amino acids are stored in your body in your

amino acid pools. Limited amounts of all the amino acids exist in amino acid pools in your blood and inside your cells, not your stomach. Your muscles contain protein but don't store surplus amino acids. Your fat stores are the result of excess calories from carbohydrates, proteins, and/or fats.

A glass of cow's milk and cookies would not be permitted if you were following ________ style of vegetarianism.

an ovo-vegetarian

Which type of vegetarian would eat an egg salad sandwich for lunch, but decline a glass of milk with their meal?

an ovo-vegetarian

Proteins act as ____________ and help to maintain proper pH in blood by picking up or donating hydrogen ions.

buffers Proteins act as buffers and help to maintain proper pH in blood by picking up or donating hydrogen ions. Typically, blood has a pH of 7.4. Even slight changes in this pH can be dangerous and even life-threatening. When blood pH is too basic, side chains on amino acids donate hydrogen ions to the blood. If the blood becomes too acidic, amino-acid side chains can grab onto excess hydrogen and reestablish acid-base balance. Enzymes are substances that act as catalysts and speed up chemical reactions without being used up in the process. Hormones are chemical messengers that elicit a specific response in the body. Catalysts are substances that help to speed up chemical reactions in the body.

Which of the following foods is a source of complete protein? chicken breast whole-grain bread pinto beans broccoli

chicken breast A chicken breast is a source of complete protein. A protein that provides all nine of the essential amino acids, along with some of the 11 nonessential amino acids, is considered a complete protein. Protein from animal sources, such as meat, fish, and poultry, is typically complete protein. Soy, a plant protein, is also a complete protein. A protein that is low or deficient in one or more of the essential amino acids is considered an incomplete protein. Protein from plant foods (such as vegetables, grains, and beans) tends to be incomplete; however, you can obtain a complete protein by combining complementary foods, such as rice and beans.

Protein is found abundantly in the

dairy group and the protein group. Both the dairy group and the protein foods group are full of protein-rich food sources. While there is some protein in vegetables, there is little in fruits. Fats do not contain protein.

complemented protein

incomplete proteins that are combined with modest amounts of animal or soy proteins or with other plant proteins that are rich in the limiting amino acids to create a complete protein

Which of these elements is found in proteins but not in carbohydrates and lipids? nitrogen carbon hydrogen oxygen

nitrogen Nitrogen is found in proteins but not in carbohydrates and lipids. Proteins, carbohydrates, and lipids all contain the elements carbon, hydrogen, and oxygen. Proteins are made of amino acids, one component of which is a nitrogen-containing amine group.

conditionally essential amino acid

nonessential amino acids that become essential if the body cannot make them, such as during bouts of illness

A body that retains more nitrogen than it excretes is in _______.

positive nitrogen balance A body that retains more nitrogen than it excretes is in positive nitrogen balance. Rapidly growing babies, children, and teenagers are all in positive nitrogen balance because their bodies use nitrogen to build new tissues that aid growth, build muscles, and expand the supply of red blood cells. Pregnant women are also in positive nitrogen balance. Nitrogen balance is the state in which an individual is consuming the same amount of nitrogen (from protein) in the diet as he or she is excreting in the urine. Healthy, nonpregnant adults are typically in nitrogen balance, or equilibrium. Negative nitrogen balance occurs when the body excretes more nitrogen than is consumed. This usually occurs due to a physical impairment such as a serious illness or injury, malnutrition, or other trauma. As a result, the body cannot synthesize protein as quickly as it's broken down.

Unless carefully planned, vegan diets may be low in which of the following essential micronutrients? vitamins D and B12, calcium, and iron vitamins C and E, thiamin, and calcium vitamins K and E, potassium, and magnesium Vitamin B12, folate, sodium, and potassium

vitamins D and B12, calcium, and iron Unless carefully planned, vegan diets may lack vitamins D and B12, calcium, and iron. These vitamins and minerals, as well as protein, zinc, vitamin A, and omega-3 fatty acids, are abundant in animal-based foods, which a vegan diet does not include. Animal-based foods are the only naturally occurring food source of B12, so it is extremely important that vegans consume fortified foods or a supplement to meet their daily needs. A well-planned vegan diet that includes a range of fruits, vegetables, legumes, grains, and vegetable oils provides ample amounts of vitamins C, E, and K, thiamin, and folate, as well as sodium, potassium, and magnesium. Although vitamin A is found only in animal-based foods, vegans can get adequate amounts by consuming beta-carotene, a plant pigment that is converted to vitamin A in the body.