Chapter 2: Chemistry of Life

Question 1

matter

Answer 1

anything that has mass and takes up space

Question 2

atom

Answer 2

smallest particle of matter. composed of subatomic particles: protons, neutrons, and electrons

Question 3

element

Answer 3

substance that cannot be broken down into simpler substances by chemical means

Question 4

4 major elements found in human body

Answer 4

hydrogen, oxygen, carbon, and nitrogen

Question 5

isotopes

Answer 5

atoms with the same atomic number but different mass numbers

Question 6

mixtures

Answer 6

physical combinations of matter

Question 7

3 types of mixtures

Answer 7

suspensions, colloids, and solutions

Question 8

solution

Answer 8

contains a solvent that dissolves a solute. The amount of solute present in a _____ is the “concentration”

Question 9

chemical bonds

Answer 9

atoms united chemically to form molecules or compounds.

Question 10

valence electrons

Answer 10

the electrons in an atom’s outermost shell

Question 11

ionic bond

Answer 11

forms when a metal and nonmetal transfer electrons to form cations and anions. The ______ results from the attraction of the pos. charged metal cation and the neg. charged nonmetal anion.

Question 12

covalent bond

Answer 12

forms when two or more atoms share electrons so that each atom obeys the octet rule

Question 13

octet rule

Answer 13

the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds.

Question 14

nonpolar covalent bonds

Answer 14

type of chemical bond that is formed when electrons are shared equally between two atoms.

Question 15

polar covalent bonds

Answer 15

unequal sharing of electrons between two nonmetals. The electrons are pulled more strongly by the more electronegative atom, and a dipole results.

Question 16

dipole

Answer 16

a partially positive and partially negative pole that forms as a result of a polar covalent bond

Question 17

hydrogen bonds

Answer 17

bond formed b/w partially (+) hydrogen atom and another partially or fully (-) electronegative atom (nitrogen, oxygen, fluorine)

Question 18

chemical reactions

Answer 18

Any time chemical bonds are formed, broken, or rearranged, or electrons are transferred between atoms

Question 19

energy

Answer 19

the capacity to do work. There are two types of _____ : potential energy and kinetic energy

Question 20

potential energy

Answer 20

energy that is stored

Question 21

kinetic energy

Answer 21

energy in motion

Question 22

3 forms of potential/kinetic energy in the body

Answer 22

chemical energy, electrical energy, and mechanical energy

Question 23

exergonic reaction

Answer 23

reaction that releases energy

Question 24

endergonic reaction

Answer 24

reaction that consumes energy

Question 25

3 types of reactions in human body

Answer 25

catabolic, exchange, and anabolic (aka synthesis).

Question 26

Catabolic (aka decomposition) reactions

Answer 26

break larger molecules into smaller ones (collapse = break down)

Question 27

exchange reaction

Answer 27

one or more atoms from the reactants are exchanged for another

Question 28

anabolic (aka synthesis) reaction

Answer 28

form larger molecules from smaller ones (anabolic = add more)

Question 29

factors for rate of reactions

Answer 29

reactants concentration, temperature, size and phase of the reactants, and presence/absence of a catalyst.

Question 30

enzymes

Answer 30

biological catalysts that increase the speed of a reaction

Question 31

water

Answer 31

acts as a solvent for substances with polar covalent and ionic bonds, which are hydrophilic, but not for those with nonpolar covalent bonds, which are hydrophobic.

Question 32

hydrophilic

Answer 32

having a tendency to dissolve in water

Question 33

hydrophobic

Answer 33

tending to repel to mix/dissolve in water

Question 34

acid

Answer 34

a molecule or other entity that can donate a proton or accept an electron pair in reactions

Question 35

base

Answer 35

a substance that can accept hydrogen ions in water and can neutralize an acid

Question 36

pH scale

Answer 36

logarithmic scale that represents the hydrogen ion concentration of a solution

Question 37

pH less than 7

Answer 37

acidic; as the pH decreases the number ____, the solution becomes more acidic.

Question 38

pH of 7

Answer 38

neutral pH level

Question 39

pH greater than 7

Answer 39

basic (alkaline); as pH increases, solution becomes more basic

Question 40

buffer

Answer 40

system of chemicals that resist a change in pH

Question 41

salt

Answer 41

metal cation bonded ionically to a nonmetal anion. _____ are electrolytes

Question 42

monomer

Answer 42

atoms or small molecules that bond together to form more complex structures such as polymers

Question 43

polymer

Answer 43

a long chain molecule that's formed from small molecules (monomers) linked together

Question 44

carbohydrates

Answer 44

primarily functions as fuel in the body but also plays a structural role

Question 45

monosaccharides

Answer 45

carbohydrate monomers

Question 46

most abundant monosaccharides in the body

Answer 46

glucose, fructose, galactose, ribose, and deoxyribose

Question 47

disaccharides

Answer 47

formed from the union of two monosaccharides by dehydration synthesis

Question 48

polysaccharides

Answer 48

consist of many monosaccharides. Glycogen is the body’s main polysaccharide

Question 49

lipids

Answer 49

stores energy, forms structural components of cell membrane, and functions as signaling molecules.

Question 50

fatty acid

Answer 50

monomer of fats. the building blocks of the fat in our bodies and in the food we eat

Question 51

triglyceride

Answer 51

3 fatty acids joined to glycerol

Question 52

phospholipid

Answer 52

contains two fatty acids and a phosphate group bonded to glycerol It is an amphiphilic molecule

Question 53

steroids

Answer 53

a class of lipids based upon a four-ring hydrocarbon steroid nucleus Any of a group of lipids (fats) that have a certain chemical structure.

Question 54

proteins

Answer 54

function as enzymes, play structural roles, are involved in movement, function in the body’s defenses, can be used as fuel, and more

Question 55

polypeptide

Answer 55

chain of amino acids (protein)

Question 56

How many levels of organization does protein have?

Answer 56

4 levels: primary, secondary, tertiary, and possible quaternary structures

Question 57

denature

Answer 57

molecule permanently loses its shape and therefore its function

Question 58

causes of denaturing

Answer 58

heat, pH changes, and certain chemicals

Question 59

nucleotide

Answer 59

a monomer composed of a nitrogenous base, a sugar, and a phosphate group

Question 60

2 types of nitrogenous bases

Answer 60

Purines= adenine (A) and guanine (G) Pyrimidines= cytosine (C), thymine (T), and uracil (U)

Question 61

adenosine triphosphate

Answer 61

(ATP) the body’s main source of chemical energy. ATP is synthesized from adenosine diphosphate (ADP) and a phosphate group.

Question 62

nucleic acids

Answer 62

DNA & RNA

Question 63

deoxyribonucleic acid

Answer 63

aka DNA, only found in cell nucleus. has 2 strands of nucleotides (double helix) joined by hydrogen bonds

Question 64

DNA

Answer 64

contains genes that provide the "recipe" or code for every protein in the body

Question 65

ribonucleic acid

Answer 65

aka RNA, single strand of nucleotides that move between cell’s nucleus and cytosol. helps assemble amino acids into a protein outside the nucleus.