Ch 6

Front 1

Protein denaturation

Back 1

protein function lost

tertiary structure gone

denature enzyme

high fever

blood pH out of normal range

Denaturation is desirable during digestion

Front 2

proteins

Back 2

large complex molecules found in cells of all living things

synthesis controlled by genetic material (DNA)

contain CHON

made from a combo of amino acids (20)

Front 3

amino acids are connected by ___

Back 3

polypeptide bonds

Front 4

Nine essential amino acids

Back 4

cannot be produced in sufficient quantities to meet physical needs

must be obtained from food

Front 5

None essential

Back 5

can be synthesized in sufficient quantities

Front 6

transamination

Back 6

transfer amine group from an essential amino acid to a different group and R group

used to make nonessential amino acids

Front 7

conditionally essential amino acids

Back 7

nonessential amino acids becomes essential

Front 8

Phenylketonuria

Back 8

PKU tyrosine becomes a conditionally essential amino acid that must be provided by the diet

Front 9

protein turn over

Back 9

existing proteins are degraded to provide the building blocks for new proteins

amino acid pool includes amino acids from food and cellular break down

Front 10

protein strands in muscle fibers are much longer than they are wide

Back 10

this structure plays an essential role in enabling muscle contraction and relaxtation

Front 11

protein denaturation

Back 11

affects shape and function

proteins uncoil and lose shape

damagin substances heat acid base heavy metal alcohol

Front 12

for protein synthesis

Back 12

all essential amino acids must be available to the cell

Front 13

limiting amino acid

Back 13

essential amino acid that is missing or in the smallest supply

Front 14

incomplete protein (low quality)

Back 14

insufficent essential amino acids. does not support growth and health, many plant sourcs

Front 15

complete protein (high quality)

Back 15

sufficient amounts of all nine essential amino acids

Front 16

mutual supplementation

complementary protein

Back 16

combine 2 or more incomplete protein sources to make a complete protein

- two or more foods are combines to supply all 9 essential amino acids for a complete protein

Front 17

protein digestion

Back 17

begins in stomach

hydrochloric acids- denatures protein strands and activates pepsin

pepsin: enzyme breaks down proteins into short polypeptides and amino acids

Gastrin : hormone controls hydrochloric acid production and pepsin release

Front 18

protein digestion

Back 18

continues in small intestine

pancreatic enzymes (proteases) complete digestion

cells in wall of small intestine complete breakdown of all polypeptides into single amino acids

peptidases- break peptide bonds

amino acids-->liver

Front 19

protein is used for fuel primarily when ___ or _____ intake is low

Back 19

energy , carbohydrate

Front 20

proteolysis

Back 20

dietary proteins are digested into amino aids or small peptides

Front 21

amino acids are transported to the ___

Back 21

liver

-made into proteins

-release into the blood for uptake by other cells for building and repair functions

Front 22

excess dietary protein

Back 22

used for energy or stored as triglycerides

Front 23

ammonia from amino acid deamination

Back 23

used as nitrogen source for synthesis of nonessentail amino acids

-high levels are toxic

-liver converts ammonia to less toxic urea

Front 24

methods for estimating protein quality

Back 24

chemical score

protein digestibility corrected amino acid score (PDCAAS)

Front 25

chemical score

Back 25

comparison: limiting amino acid in a food vs. reference food

the amino acid found to have to lowest proportion in the test food as compared to the reference food is defined as the limiting amino acid

Front 26

PDCAAS

Back 26

uses chemical score and a correction factor for digestibility to calculate a value for protein quality

-protein with higher digestibility are more complete

-impractical measures not used for individual diet planning

Front 27

functions of proteins

Back 27

cell growth ,repair, maintenance

-enzymes and hormones

-fluid and electrolyte balance

-acid base balance

-immune system

-energy source

-nutrition transport and storage

Front 28

______determines protein needs

Back 28

Nitrogen balance

Front 29

Positive

(-) nitrogen balance

Back 29

+ body is retaining or adding protei: growth, pregnancy or recovery form illness or a protein deficiency

- body is losing protein: starvation of very low energy diets severe ilness infections high fever burns

Front 30

RDA

Back 30

.8 per kg body weight per day

recommented percentage of energy is 10-15%

proteins needs are higher during growth and development

Front 31

too much protein

Back 31

high cholesterol and heart disease

contribution to bone loss

kidney diease

Front 32

vegetarism

Back 32

restricting the diet to foods of plant origin

can be low in some nutrients

Front 33

protein energy malnutrtion

Back 33

caused by inadequate protein and energy intake

Front 34

marasmus

Back 34

grossly inadequate energy and nutrient intake

-most common in children living in impoverished conditions

Front 35

kwashiorkor

Back 35

disease resulting in low protein intake

causes person to look swollen in belly