Chapter 6: Proteins

Question 1

amino acids

Answer 1

The building blocks of proteins. Each contains central carbon atom, an amino group, an acid group, and a side chain.

Question 2

essential amino acids

Answer 2

Cannot be synthesized by the body in sufficient amounts to meet the needs and therefore must be included in the diet.

Question 3

nonessential amino acids

Answer 3

Can be synthesized y the human body in sufficient amounts to meet their needs.

Question 4

Transamination

Answer 4

The process by which an amino group from one amino acid is transferred to a carbon compound to form a new amino acid.

Question 5

conditionally essential amino acids

Answer 5

amino acids that are essential in the diet only under certain conditions or a certain times of life. (ex. only if there is enough phenylalanine in the diet is there going to be enough tyrosine)

Question 6

dipeptide

Answer 6

Two amino acids linked by a peptide bonds.

Question 7

tripeptide

Answer 7

3 amino acids linked by peptide bonds

Question 8

polypeptide

Answer 8

A chain of 3+ amino acids linked by peptide bonds

Question 9

primary structure

Answer 9

Linear sequence of amino acids

Question 10

secondary structure

Answer 10

Shapes within parts of a protein (e.g. beta-pleated sheet, helical, linear)

Question 11

tertiary structure

Answer 11

Final 3D Structure
-Multiple polypeptide chains linked together (a protein) create a specific 3D shape to perform a specific task. If the shape is altered in any way the protein will NOT work the same way.

Question 12

denaturation

Answer 12

the alteration of protein’s 3D structure. This can be caused by certain changes in the environment such as an increased temperature of pH.

Question 13

Why is protein important? (5)

Answer 13

1. Regulating body processes
2. Growth and Repair of Tissues
3. Immune Deficiency
4. Transportation
5. Energy (as a last resort if the body has not fat or CHO

Question 14

amino acid pool

Answer 14

All of the amino acids in body tissues and fluids that are available for use by the body.

Question 15

deamination

Answer 15

the removal of the amino acid group from an amino acid

Question 16

amino acid pool allows for… (3)

Answer 16

1. Energy production
2. Synthesis of glucose or fatty acids
3. Synthesis of nonprotein molecules that contain nitrogen

Question 17

protein turnover

Answer 17

the continuous synthesis and breakdown of body proteins

Question 18

gene

Answer 18

a length of DNA containing the information need to synthesize RNA or a polypeptide

Question 19

transcription

Answer 19

the process of copying the information in DNA to a molecule of mRNA

Question 20

translation

Answer 20

the process of translation mRNA code into the amino acid sequence of a polypeptide chain

Question 21

limiting amino acid

Answer 21

the essential amino acid that is available in the lowest concentration in relation to the body’s needs

Question 22

gene expression

Answer 22

the events of protein synthesis in which the information coded in a gene is used to synthesize a product, either a protein or a molecule of RNA

Question 23

neurotransmitters

Answer 23

molecules that function to transfer signals between the cells of the nervous system and can stimulate or inhibit a signal

Question 24

urea

Answer 24

a nitrogen-containing waste product formed from the breakdown of amino acids that is excreted in the urine

Question 25

antibodies

Answer 25

proteins produced by the bodes immune system that recognize foreign substances in the body and help to destroy them

Question 26

protein-energy malnutrition (PEM)

Answer 26

a condition characterized by wasting and an increased susceptibility to infection that results from the long-term consumption of insufficient amounts of energy and protein to meet needs

Question 27

kwashiorkor

Answer 27

a form of protein-energy malnutrition in which only protein is deficient

Question 28

marasmus

Answer 28

a form of protein-energy malnutrition in which a deficiency of energy in the diet causes severe body wasting

Question 29

protein excess causes (4)

Answer 29

1. Hydration and kidney function (if kidneys do not work well already extra stress is added to them) 2. Bone health (excess calcium is lost in the urine) 3. Kidney stones (in creased risk) 4. Heart disease and cancer risk (high protein = high animal products = high risk CHD)

Question 30

phenylketonuria (PKU)

Answer 30

an inherited disease in which the body cannot metabolize the amino acid phenylalanine. If the disease is untreated, toxic by-products called phenylketones accumulate in the blood and interfere with brain development

Question 31

celiac disease

Answer 31

a disorder that causes damage to the intestines when the protein gluten is eaten

Question 32

nitrogen balance

Answer 32

the amount of nitrogen consumed in the diet compared with the amount excreted by the body over a given period of time

Question 33

negative nitrogen balance

Answer 33

nitrogen intake < nitrogen output the total body protein decreases e.g. when severely burned

Question 34

positive nitrogen balance

Answer 34

nitrogen intake > nitrogen output total body protein increases e.g. when pregnant

Question 35

High protein needs

Answer 35

pregnant and lactating women, the ill, those who exercise, and children

Question 36

protein quality

Answer 36

a measure of how efficiently a protein in the diet can be used to make body proteins

Question 37

complete dietary protein

Answer 37

protein that provides essential amino acids in the proportions needed to support protein synthesis

Question 38

incomplete dietary protein

Answer 38

protein that is deficient in one or more essential amino acids relative to body needs

Question 39

chemical or amino acid score

Answer 39

a measure of protein quality determined by comparing the essential amino acid content of the protein in a food with that in a reference protein. The lowest amino acid ratio calculated is the chemical score

Question 40

protein digestibility-corrected amino acid score (PDCAAS)

Answer 40

a measure of protein quality that reflects a protein's digestibility as well as the proportions of amnio acids it provides

Question 41

protein efficiency ratio

Answer 41

A measure of protein quality determined by comparing the weight gain of a laboratory animal fed a test protein wit the wight gain of an animal fed a reference protein

Question 42

net protein utilization

Answer 42

a measure of protein quality determined by comparing the amount of nitrogen retained in the body with the amount eaten in the diet

Question 43

biological value

Answer 43

a measure of protein quality determined by comparing the amount of nitrogen retained in the body with the amount absorbed from the diet

Question 44

protein complementation

Answer 44

the process of combining proteins from different sources so that they collectively provide the proportions of amino acids required to meet needs

Question 45

vegetarianism

Answer 45

a pattern of food intake that eliminates some or all animal products

Question 46

vegan

Answer 46

a pattern of food intake that eliminates all animal products

Question 47

risks of missing animal products

Answer 47

lack of B vitamins, calcium, vitamin D, iron, zinc, DHA, and EPA