Chpt. 6 Proteins

Protein digestion: liver

Amino acids are transported here, where they are: -converted to glucose or fat -used for energy or to build to proteins -sent to the cells as needed

Conditionally essential amino acids

Amino acids that are normally considered nonessential but become essential under certain circumstances when the body's need for them exceeds the ability to produce them.

rRNA

At the beginning of the translation stage it helps mRNA bind to a ribosome

Which of the following is a protein? Triglycerides Disaccharide Enzymes Estrogen

Enzymes

_____ foods are sources of fat-soluble vitamins. Nonfatty Fat-containing Water-containing Less-cooked

Fat-containing

Water-soluble vitamins need to be consumed _____. not at all occasionally through supplements regularly

regularly

Protein digestion: stomach

-Proteins are denatured by hydrochloric acid -Pepsin is activated to break proteins into single amino acids and smaller polypeptides

Ribosome

-Reads the mRNA strand, and with the help of tRNA builds the corresponding amino acid chain - Releases the amino acid chain once it's complete

The structure of each protein molecule is dictated by _________. cell membranes amino acids genetic material blood lipid levels

genetic material

RDA for protein

-sedentary: 0.8 g per kg per day - 10 to 35% of total energy intake

Currently, _____ levels of protein structure have been identified. 12 4 10 6

4

The recommended protein intake for a 110-pound (50-kg) adult is _______. 110 g 40 g 88 g 50 g

40 g

Nonessential amino acids

Alanine Arginine Asparagine Aspartic acid Cysteine Glutamic acid Glutamine Glycine Proline Serine Tyrosine

Transport Proteins

Protein molecules that help transport substances throughout the body and across cell membranes

Complementary proteins

Two or more foods that together contain all nine essential amino acids necessary for a complete protein. It is not necessary to eat complementary proteins at the same meal.

tRNA

Type of RNA that plays an important role of transferring specific amino acids to the growing amino acid chain in the ribosomes

Peptide bonds

Unique types of chemical bonds in which the amine group of one amino acid binds to the acid group of another in order to manufacture dipeptides and all larger peptide molecules

_____ is often a nutrient of concern in vegetarian diets. Vitamin B6 Vitamin D Vitamin K Vitamin E

Vitamin D

High protein intake may contribute to ______. hair loss calcium excretion dementia muscle atrophy

calcium excretion

Phenylketonuria (PKU) is a disease in which the body cannot metabolize _____. proline phenylalanine conditionally essential amino acids essential amino acids

phenylalanine

Pregnant women are in ____ nitrogen balance. neutral positive temporary negative

positive

Chemical digestion of protein begins in the ______. pancreas small intestine stomach mouth

stomach

Overall, it is easier to develop a _______ nutrients from supplements than from foods. need for toxic overload of resistance to distaste for

toxic overload of

Edema

A disorder in which fluids build up in the interstitial spaces causing fluid imbalances and a swollen appearance

Acidosis

A disorder in which the blood becomes acidic. Can be caused by respiratory or metabolic problems

Alkalosis

A disorder in which the blood becomes basic. It can be caused by respiratory or metabolic problems.

Gene

A segment of DNA that encodes for the production of a specific protein

Complete proteins

Foods that contain all nine essential amino acids

Protein digestion: mouth

Proteins in foods are crushed by chewing and moistened by saliva

Deanimation

The process by which an anime group is removed from an amino acid. the nitrogen is then transported to the kidneys for excretion in the urine, while the carbon and other components are metabolized for energy or used to make other compounds

Gene expression

The process of using a gene to make a protein

Amino Acids

-Building blocks of proteins -Contain nitrogen (and H & C)

Nonessential Amino Acids

-Can be manufactured by the body in sufficient quantities -Do not need to be consumed regularly in a diet -The human body can make 11 on its own

Function of proteins

-Contribute to cell growth, repair and maintenance -Act as enzymes and hormones -Maintain fluid and electrolyte balance -Help maintain acid-base balance -Help maintain a strong immune system -Serve as an energy source -Assist in the transport and storage of nutrients

Protease

-Enzyme -Produced in the pancrease -Released into small intestine -Continues the breakdown of polypeptides after pepsin

Pepsin

-Enzyme -Stomach -Begins breakdown of proteins into shorter polypeptide chains and single amino acids

Incomplete proteins

-Foods that do not contain all of the essential amino acids in sufficient amounts to support growth and health.

mRNA

-Leaves the nucleus and goes to the ribosome where the protein is build -It carries a copy of the DNA instructions that dictate the sequence of amino acids for making a specific rptoein -The ribosome moves along this and reads the encoded information

Essential Amino Acids

-Not produced by the body -Must be obtained by food

Protein digestion: small intestine

-Proteases are secreted to digest polypeptides into smaller units -Cells in teh wall of the small intestine complete the breakdown of dipeptides and tripeptides into single amino acids, which are absorbed into the blood stream

Trace minerals are those we need to consume in amounts less than _____ mg per day. 100 50 1,000 500

100

The body can make ______ nonessential amino acids. 15 11 5 7

11

What secretions are needed to digest complex proteins into single amino acids for absorption? saliva from the salivary glands in the mouth All of the listed responses are correct. proteases secreted from the pancreas and the small intestine hydrochloric acid and pepsin in the stomach

All of the listed responses are correct.

Neurotransmitters

Chemical compounds that transmit messages from one nerve cell to another

Essential amino acids

Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine

Which of the following groups of amino acids are essential? Alanine, arginine, aspartic acid Cysteine, proline, serine Glutamic acid, glutamine, glycine Methionine, phenylalanine, tryptophan

Methionine, phenylalanine, tryptophan

Buffers

Proteins that help maintain proper acid-base balance by attaching to or releasing hydrogen ions as conditions change in the body

Which of the following vegetarian foods is almost identical in quality to meat? Soybeans Nuts Kidney beans Brown rice

Soybeans

Limiting amino acid

The essential amino acid that is missing or in the smallest supply in the amino acid pool and is thus responsible for slowing or halting protein synthesis

How does your body use the protein once it has been ingested? Consider the following statements and select the correct ones regarding protein use. Select all that apply. The liver uses amino acids to create glucose. Amino acids are used to create new proteins. If you ingest more protein than your body needs, the protein is stored in muscle. If calorie intake is inadequate, amino acids can be used for production of energy.

The liver uses amino acids to create glucose. Amino acids are used to create new proteins. If calorie intake is inadequate, amino acids can be used for production of energy.

When variations, also called mutations, occur within genes, the proteins that are encoded by those genes are modified. Many times, mutations occurring in genes do not result in noticeable effects on the proteins synthesized from them, and are, therefore, harmless. Other times, however, a certain genetic mutation may affect the final structure and function of a protein enough to result in disease. Which of the following statements correctly applies to the genetic disorders sickle-cell anemia and phenylketonuria? PKU is one of the most common inherited blood disorders in the United States. The bodies of individuals with PKU are unable to metabolize the amino acid tryptophan, and it builds up in the blood. Sickle-cell anemia occurs when two amino acids are changed within one of the four polypeptide chains that make up the hemoglobin protein. Sickle-cell anemia can result in mental retardation if not identified and treated early in life. The mutation that causes sickle-cell results in production of hemoglobin proteins which are misshapen; some of them look like half-moons.

The mutation that causes sickle-cell results in production of hemoglobin proteins which are misshapen; some of them look like half-moons.

Mutual supplementation

The process of combining two or more incomplete protein sources to make a complete protein

Transanimation

The process of transferring the amine group from one amino acid to another in order to manufacture a new amino acid.

Translation

The process that occurs when the genetic information carried by messenger RNA is translated into a chain of amino acids at the ribosome.

Transcription

The process through which messenger RNA copies genetic information from DNA in the nucleus.

The body uses two types of amino acids: essential and nonessential. Which of the following statements about essential and nonessential amino acids is correct? There are 11 nonessential amino acids. Nonessential amino acids cannot be produced in our bodies. Our bodies can produce essential amino acids when the amino acid pools are diminished. There are 11 essential amino acids.

There are 11 nonessential amino acids.

A molecule with four to nine amino acids joined together by peptide bonds is referred to as __________. a tripeptide a polypeptide a quatropeptide an oligopeptide

an oligopeptide

Most minerals are better absorbed from _____ sources than they are from supplements. animal food plant synthetic unprocessed food

animal food

Minerals can undergo minor modifications and change their _____ structure. atomic molecular essential chemical

atomic

High-protein intake is associated with high _______. mental functioning energy levels metabolism blood cholesterol

blood cholesterol

Small family farming is a more _________form of raising livestock. efficient modern environmentally friendly profitable

environmentally friendly

Minerals are ________ elements. benign nonessential inorganic organic

inorganic

Symptoms such as edema, distention of the belly, loss of appetite, skin problems, and retarded growth and development are often associated with _______. excess protein intake kwashiorkor marasmus edema

kwashiorkor

A serious protein-energy malnutrition disease is ______. diabetes marasmus osteoporosis goiter

marasmus

The link between beriberi and thiamin was first found through _____. randomized trials clinical trials observation case studies

observation

Toxicity from water-soluble vitamins is _____. common increasing declining rare

rare

An example of mutual supplementation would be ___. Whole wheat bread and almond butter sandwich red beans and rice meat and potatoes berries and cream

red beans and rice