Chapter 6: Proteins

Question 1

proteins

Answer 1

Macromolecules
composed of monomeric subunits, called amino acids

Question 2

amino acids

Answer 2

Simple monomers
composed of the elements carbon, oxygen, hydrogen, and nitrogen.

Question 3

nonpolar amino acids

Answer 3

Hydrophobic amino acids with side groups that are long or bulky.

Question 4

polar amino acids

Answer 4

Hydrophilic amino acids that are not charged.

Question 5

basic amino acids

Answer 5

Hydrophilic amino acids that are positively charged.

Question 6

acidic amino acids

Answer 6

Hydrophilic amino acids that are negatively charged

Question 7

nonessential amino acids

Answer 7

Amino acids that are made in the human body.

Question 8

essential amino acids

Answer 8

Amino acids that are not
made by humans and must be obtained from the diet.

Question 9

conditionally essential amino acids

Answer 9

Amino acids that become
essential during certain times in life, such as child growth

Question 10

transcription

Answer 10

Process of copying DNA into messenger RNA.

Question 11

translation

Answer 11

Process of decoding messenger RNA and synthesizing a protein.

Question 12

protein folding

Answer 12

A sequence of amino acids transforms into its dictated shape

Question 13

nucleotide

Answer 13

A structural base and building block for DNA and RNA.

Question 14

peptide bond

Answer 14

The chemical bond that connects amino acids in a sequence.

Question 15

hydrochloric acid

Answer 15

Secreted by stomach cells; aids in the chemical breakdown of proteins.

Question 16

denaturation

Answer 16

The physical changes that take place in a protein when it is exposed to abnormal conditions in the environment.

Question 17

pepsin

Answer 17

An enzyme secreted by stomach cells. It breaks the peptide bonds between amino acids, producing much shorter protein fragments.

Question 18

protein turnover

Answer 18

The processes of
continually breaking down proteins and building new ones.

Question 19

collagen

Answer 19

The most abundant protein in the human body. It is a strong fibrous rope that plays a role in structure, motion, protection, and tissue repair and regeneration

Question 20

elastin

Answer 20

A fibrous protein that allows connective tissues, such as skin and tendons, to stretch back into their original shape

Question 21

keratin

Answer 21

A fibrous protein that provides skin, hair, and nails with structure

Question 22

actin

Answer 22

A contractile protein in muscle cells.

Question 23

myosin

Answer 23

A contractile protein in muscle cells

Question 24

enzymes

Answer 24

Proteins that conduct a specific chemical reaction in order to transform substrates into a product.

Question 25

albumin

Answer 25

A butterfly-shaped protein that plays a role in fluid balance, acid-base balance, and the transport of biological molecules.

Question 26

lysozome

Answer 26

An enzyme that destroys bacteria.

Question 27

antibodies

Answer 27

A protein that protects against unwanted intruders.

Question 28

Kwashiorkor

Answer 28

A syndrome of severe protein and micronutrient deficiency, characterized by swelling (edema) of the feet and abdomen, poor skin health, growth retardation, low muscle mass, and liver malfunction.

Question 29

marasmus

Answer 29

A syndrome of severe protein and energy deficiency, characterized by emaciation, poor skin health, and growth retardation.

Question 30

marasmic kwashiorkor

Answer 30

The combined syndrome of severe protein and energy deficiency, characterized by variable edema, emaciation, poor skin health, and growth retardation.

Question 31

nitrogen balance

Answer 31

When the amount of protein input into the body equals the amount used up and excreted.

Question 32

incomplete protein sources

Answer 32

Foods that contain some of the essential amino acids.

Question 33

complete protein sources

Answer 33

Foods that contain all nine of the essential amino acids

Question 34

complementary foods

Answer 34

A combination of foods that when consumed together (though not necessarily at the same time) contain all nine essential amino acids at adequate levels.

Question 35

sarcopenia

Answer 35

The age-related decline in muscle mass