Proteins

Front 1

An amino acid has a central carbon atom bonded to:

Back 1

A hydrogen atom (H), an amino group (NH2), a carboxylic acid group (COOH), and an R-group which gives the amino acid its unique characteristics.

Front 2

Condensation reaction in which a hydroxyl group (OH) of one amino acid is joined with a hydrogen atom (H) of another amino acid, and a water molecule is released.

Back 2

Peptide Bond

Front 3

Proteins are classified based on their number of amino acids:

Back 3

dipeptides, tripeptides, oligopeptides (2-12), and polypeptides (>12)

Front 4

We need ___ different amino acids to make all of the proteins required by the body.

Back 4

20

Front 5

There are ___ essential amino acids that are not made in the body and must be consumed in the diet. And there are ___ nonessential amino acids that can be synthesized in the body by transamination.

Back 5

9, 11

Front 6

Amino acids become conditionally ___________ when the body is unable to synthesize one or more nonessential amino acids.

Back 6

Essential

Front 7

Transfer of an amino group from one amino acid to another organic compound (a keto acid) to form a different amino acid.

Back 7

Transamination

Front 8

Contains adequate relative amounts of all essential amino acids

Back 8

Complete protein source

Front 9

_____________-derived foods are considered complete protein sources

Back 9

Animal

Front 10

Contains very low amounts of one or more essential amino acids.

Back 10

Incomplete protein source

Front 11

Combining foods with incomplete proteins to provide adequate amounts of all essential amino acids is called:

Back 11

Protein Complementation

Front 12

Examples of Protein Complementation are:

Back 12

Rice and beans

Corn and beans

Front 13

Determined by complete vs incomplete and bioavailability.

Back 13

Protein quality

Front 14

_____________ protein source is complete and bioavailable and is derived from animal sources.

Back 14

High-quality

Front 15

______________ protein source is incomplete and/or not bioavailable and is derived from plant sources.

Back 15

Low-quality

Front 16

turning on protein synthesis for a certain protein

Back 16

Up-regulation

Front 17

turning off protein synthesis for a certain protein

Back 17

Down-regulation

Front 18

Sequence of amino acids that makes up a single polypeptide chain. Determines how the polypeptide will be folded into its final protein shape.

Back 18

Primary structure

Front 19

determines chemical and physical characteristics critical to protein's function

Back 19

Protein shape

Front 20

Weak ________ bonds between elements of the amino acid backbone cause folding of a primary structure and results in a secondary structure

Back 20

hydrogen

Front 21

common patterns of a secondary structure

Back 21

a-helix or a B-folded sheets

Front 22

Additional folding of a polypeptide to form a functional 3-dimensional protein. This structure is due to interactions between R-groups. Strong disulfide bonds (S-S) between sulfur-containing amino acids.

Back 22

Tertiary Structure

Front 23

Combination of several polypeptide chains to form a complex protein. Example: Hemoglobin and its prosthetic groups (hemes).

Back 23

Quaternary Structure

Front 24

Alteration of a protein's 3-dimensional structure by heat, agitation, acid, chemicals, enzymes, or heavy metals such as lead or mercury.

Back 24

Denaturation

Front 25

Some seafoods such as: __________... are high in mercury.

Back 25

Shark, swordfish, king mackerel, tilefish, shrimp, tuna, salmon, pollock, and catfish

Front 26

Alteration of DNA sequence (gene) resulting in an alteration of amino acid sequence. May influence metabolism or cause disease (sickle cell, PKU, and cancer). MAy be heritable.

Back 26

Mutation

Front 27

Alteration of a gene that is present in at least 1% of a population. Can influence response to nutrients and overall health.

Back 27

Polymorphism

Front 28

Alterations in gene expression that do not involve changes in DNA sequence. Some changes can be inherited. Nutrition likely determines some of these alterations. Ex. fetal malnutrition may increase risk of disease in later life.

Back 28

Epigenetics

Front 29

1990s project to describe all genes making up human chromosomes. Found humans have only ~30,000 genes

Back 29

Human Genome Project

Front 30

Study of how inherited genetic variations influence the body's responses to specific nutrients.

Back 30

Nutrigenetics

Front 31

Study of how nutrition and genetics interact to influence health. Nutritionists can now study how dietary factors help turn a gene on or off.

Back 31

Nutrigenomics

Front 32

Academy of Nutrition and Dietetics and the American College of Sports Medicine agree that athletes need a _______ protein intake.

Back 32

higher

Front 33

Power athletes need:

Back 33

1.2-1.7 gr/kilogram/day

Front 34

Endurance athletes need:

Back 34

1.2-1.4 gr/kilogram/day

Front 35

_________________ must be transported into the brush border (enterocytes) through passive and active transport.

Back 35

Amino acids

Front 36

Absorption of proteins occurs in the _______________. Amino acids enter blood, and circulate to liver via Hepatic portal system.

Back 36

Duodenum

Front 37

Help the body maintain blood glucose at appropriate levels

Back 37

Proteins

Front 38

Generate ATP to power chemical reactions when glucose and fat availability is limited.

Back 38

Proteins

Front 39

Excess dietary protein is stored as ________.

Back 39

fat

Front 40

Amino acids that can be converted to glucose via gluconeogenesis.

Back 40

Glucogenic amino acids

Front 41

synthesis of glucose from non-carbohydrate sources such as amino acids

Back 41

gluconeogenesis

Front 42

Steps of Gluconeogenesis:

Back 42

1. Deamination: removal of an amino group from amino acid.

2. Carbon skeletons are converted to glucose and used to form ATP.

Front 43

balance between protein degradation and protein synthesis

Back 43

Protein turnover

Front 44

In the body, amino acids that are immediately available to cells for protein synthesis and other purposes.

Back 44

Labile amino acid pool

Front 45

Insulin promotes protein synthesis. The thyroid hormone and cortisol stimulate protein degradation.

Back 45

Protein turnover is regulated by hormones

Front 46

Deamination produces _______, which is toxic.

Back 46

Ammonia (NH3)

Front 47

A relatively nontoxic nitrogen-containing compound produced from ammonia in the liver.

Back 47

Urea