Principles Of Nutrition Chapter 6

Front 1

Proteins

Back 1

Compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain. Some amino acids also contain sulfur atoms.

Front 2

Amino Acids

Back 2

Building blocks of proteins

Front 3

What is the structure of a typical amino acid?

Back 3

Each contains an amino group, an acid group, a hydrogen atom, and a distinctive side group. all attached to a central carbon atom.

Front 4

Nonessential Amino Acids

Back 4

Amino acids that the body can synthesize

Front 5

Essential Amino Acids

Back 5

Amino acids that the body cannot synthesize in amounts sufficient to meet physiological needs

Front 6

Conditionally essential amino acids

Back 6

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

Front 7

Peptide bond

Back 7

a bond that connects the acid end of one amino acid to the amino end of another, forming a link in a protein chain

Front 8

Dipeptide

Back 8

two amino acids bonded together

Front 9

Tripeptide

Back 9

three amino acids bonded together

Front 10

Polypeptide

Back 10

many (ten or mor) amino acids bonded together

Front 11

Hemoglobin

Back 11

the globular protein of the red blood cells that carries oxygen from the lungs to the cells throughout the body

Front 12

Denaturation

Back 12

the change in a protein's shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents

Front 13

Pepsin

Back 13

a gastric enzyme that hydrolyzes protein

Front 14

Pepsinogen

Back 14

the inactive form of pepsin that is activated by hydrochloric acid in the stomach

Front 15

Proteases

Back 15

enzymes that hydrolyze protein

Front 16

Peptidase

Back 16

a digestive enzyme that hydrolyzes peptide bonds

Front 17

Proteomics

Back 17

the study of the body's proteins

Front 18

transcription

Back 18

the process of messenger RNA being made from a template of DNA

Front 19

Translation

Back 19

the process of messenger RNA directing the sequence of amino acids and synthesis of proteins

Front 20

Sickle-cell anemia

Back 20

a hereditary form of anemia characterized by abnormal sickle- or crescent-shaped red blood cells. These cells interfere with oxygen transport and blood flow.

Front 21

What are symptoms of sickle-cell anemia precipitated by?

Back 21

dehydration and insufficient oxygen (as may occur at high altitudes)

Front 22

What are the symptoms of sickle-cell anemia?

Back 22

hemolytic anemia (red blood cells burst), fever, and severe pain in the joints and abdomen

Front 23

Gene expression

Back 23

the process by which a cell converts the genetic code into RNA and protein

Front 24

Enzymes

Back 24

proteins that facilitate chemical reactions without being changed int he process; protein catalysts

Front 25

Fluid Balance

Back 25

Maintenance of the proper types and amounts of fluids in each compartment of the body fluids

Front 26

Edema

Back 26

the swelling of body tissue caused by excessive amounts of fluid in the interstitial spaces; seen in protein deficiency (among other conditions)

Front 27

Acids

Back 27

compounds that relase hydrogen ions in a solution

Front 28

Bases

Back 28

compounds that accept hydrogen ions in a solution

Front 29

Acidosis

Back 29

above-normal acidity in the blood and body fluids

Front 30

Alkalosis

Back 30

above-normal alkalinity (base) in the blood and body fluids

Front 31

Antigens

Back 31

substances that elicit the formation of antibodies or an inflammation reaction from the immune system. A bacterium, a virus, a toxin, and a protein in food that cause allergy are all examples of these.

Front 32

Antibodies

Back 32

large proteins of the blood and body fluids, produced by the immune system in response to the invasion of the body by foreign molecules (usually proteins called antigens). They combine with and inactive the foreign invaders, thus protecting the body.

Front 33

Immunity

Back 33

the body's ability to defend itself against diseases

Front 34

Protein Turnover

Back 34

the degradation and synthesis of protein

Front 35

Amino Acid Pool

Back 35

the supply of amino acids derived from either food proteins or body proteins that collect in the cells and circulating blood and stand ready to be incorporated in proteins and other compounds or used for energy

Front 36

Nitrogen Balance

Back 36

the amount of nitrogen consumed (N in) as compared with the amount of nitrogen excreted (N out) in a given period of time

Front 37

Deamination

Back 37

removal of the amino (NH3) group from a compound such as an amino acid

Front 38

High Quality Proteins

Back 38

dietary proteins containing all the essential amino acids in relatively the same amounts that human being require. They may also contain nonessential amino acids.

Front 39

Protein Digestibility

Back 39

a measure of the amount of amino acids absorbed from a given protein intak

Front 40

Limiting Amino Acid

Back 40

the essential amino acid found in the shortest supply relative to the amounts needed fro protein synthesis in the body.

Front 41

Complementary Proteins

Back 41

two or more dietary proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other

Front 42

Protein-Energy Malnutrition (PEM)

Back 42

a deficiency of protein, energy, or both, including kwashiorkor, marasmus, and instances in which they overlap

Front 43

Acute PEM

Back 43

Protein-energy malnutrition caused by recent severe food restriction; characterize in children by thinness for height (wasting)

Front 44

Chronic PEM

Back 44

protein-energy malnutrition caused by long-term food deprivation; characterize in children by short height for age (stunting)

Front 45

Marasmus

Back 45

a form of PEM that results from a severe deprivation, or impaired absorption, of energy, protein, vitamins,and minerals

Front 46

Kwahiorkor

Back 46

a form of PEM that results either from inadequate protein intake or, more commonly, from infections.

Front 47

Dysentery

Back 47

an infection of the digestive tract that causes diarrhea

Front 48

Whey protein

Back 48

a by-product of cheese production; falsely promoted as increasing muscle mass. It is the water part of milk that separates from the curds.

Front 49

DNA

Back 49

the double helix molecules of which genes are made

Front 50

Gene Expression

Back 50

the process by which a cell converts the genetic code into RNA and protein

Front 51

Genes

Back 51

sections of chromosomes that contain the instructions needed to make one or more proteins

Front 52

Phenylketonuria

Back 52

an inherited disorder characterize by failure to metabolize the amino acid phenylalanine to tyrosine

Front 53

RNA

Back 53

a compound similar to DNA, but it is a single strand with a ribose sugar instead of a deoxyribose sugar and uracil instead of thymine as one of its bases

Front 54

How many essential amino acids are there for humans?

Back 54

9

Front 55

Name the 9 essential amino acids.

Back 55

Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Trytophan, Valine

Front 56

How many common amino acids are there?

Back 56

20

Front 57

How are proteins formed?

Back 57

Chemically speaking, proteins are more complex than carbohydrates or lipids, being made of some 20 different amino acids. Cells link amino acids together in a series of condensation reactions to form peptide bonds which create proteins. The distinctive sequence of amino acids in each protein determines its unique shape and function.

Front 58

What are the primary functions of protein in the body?

Back 58

1) Building materials for growth and maintenance
2) Enzymes
3) Hormones (not all are protein, some are made from cholesterol)
4) Regulators of Fluid Balance
5) Acid-Base regulators
6) Transporters
7) Antibodies
8) A Source of Energy and Glucose

Front 59

What is the current RDA for protein?

Back 59

0.8 g/kg/day
and
10-35% of energy intake

Front 60

When will a positive nitrogen occur?

Back 60

when the body synthesizes more than it degrades - growing infants, children, adolescents, pregnant women, and people recovering from protein deficiency or illness

Front 61

When will a negative nitrogen occur?

Back 61

the body degrades more than it synthesizes and loses protein - people who are starving or suffering other severe stresses such as burns, injuries, infections, and fever

Front 62

Name some high-quality protein foods

Back 62

foods derived from animals - meat, fish, poultry, cheese, eggs, yogurt, and milk
Soy protein

Front 63

Name some low-quality protein foods

Back 63

Corn protein and some other plant proteins