Chapter 2: Chemical Basis Of Life Flashcards

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1
Q

what is an element?

A

a pure substance of 1 kind of atom

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2
Q

what is an atom?

A

the smallest functional unit of matter

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3
Q

what are the parts of an atom?

A

protons, neutrons, electrons

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4
Q

what are protons?

A

positive charge

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5
Q

what are neutrons?

A

no charge

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6
Q

what are electrons?

A

negative charge

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7
Q

how is an atom arranged?

A

the protons and neutrons are in the center of the nucleus. the electrons are arranged in orbitals around the nucleus. The first 2 electrons are in the first orbital and the rest are in the second

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8
Q

are the nucleus of a cell and atom different?

A

yes. the cell is a physical structure where the atoms is not

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9
Q

what makes up most of the weight of an atom?

A

the protons and neutrons because they both have an atomic mass of 1. The electrons have an atomic mass way less than 1 so they don’t weigh much

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10
Q

elements in the same column on the periodic table have similar…

A

properties

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11
Q

how are elements arranged?

A

by atomic number

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12
Q

what is the net charge of an atom?

A

it is zero or uncharged because the protons equal the electrons canceling each other.

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13
Q

what is atomic mass?

A

it is mainly based on #protons and neutrons

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14
Q

electrons are involved in what but have very little…

A

bonding
mass

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15
Q

what is electronegativity?

A

the ability of an atom to attract/ gain electrons

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16
Q

electronegativity increases which way on the periodic table?

A

left-right

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17
Q

when atoms lose an electron, what charge do they have?

A

positive charged ion

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18
Q

when atoms gain an electron, they have what charge?

A

a negative charged ion

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19
Q

noble gases are nonreactable because…

A

their outer most orbital is full

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20
Q

how do elements become the most stable?

A

have a full outer orbital or be completely empty

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21
Q

what are ions?

A

atoms that have gained or lost electrons

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22
Q

what are ions?

A

atoms that have gained or lost electrons

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23
Q

are ions charged particles?

A

yes. they can either be negative or positive

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24
Q

what do ions have to add up to in an ionic bond?

A

zero

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25
Q

when do opposites attract?

A

with ionic bonds

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26
Q

what are molecules?

A

made up of 2 or more atoms that are connected together by bonds. they can either be the same atom or different atoms (compound).

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27
Q

a molecule has a net charge of…

A

zero

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28
Q

ionic bonds are always charged and is between…

A

ions

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29
Q

what is a covalent bond?

A

when the electrons are shared between the atoms so there is no charge because there are no electrons.

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30
Q

why do they want to share a pair of electrons?

A

to become more stable

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31
Q

what is a type of covalent bond?

A

disulfide bonds

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32
Q

electrons are shared between two atoms

A

covalent bonds

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33
Q

hydrogen bonds are very…

A

weak

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34
Q

bond formed between a positively charged ion and a negatively charged ion

A

ionic bonds

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35
Q

what bond? Na+Cl-
C-C, C-H

A

ionic
covalent

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36
Q

what is a nonpolar covalent bond?

A

electrons are shared evenly between 2 atoms

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37
Q

what is a polar covalent bond ?

A

electrons are shared between 2 atoms, but they spend more time near one atom than the other. one end is partially positive and the other is negative

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38
Q

what type of atoms are electron hogs?

A

electronegative atoms

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39
Q

electrons spend more time near what?

A

the electronegative atoms than near other atoms

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40
Q

what is a polar molecule?

A

has a partial positive or partial negative charge at one end of molecule.

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41
Q

electronegative atoms in biological molecules are

A

O and N

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42
Q

what is a single bond?

A

a covalent bond that one pair of electrons is shared between atoms

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43
Q

what is a double bond?

A

a covalent bond that two pairs of electrons are shared between atoms

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44
Q

what is a triple bond?

A

a covalent bond where three pairs of electrons are shared between atoms

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45
Q

what is a disulfide bonds?

A

a covalent bond between two sulfur atoms S-S

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46
Q

what is a hydrogen bond?

A

a very weak bond that can break easily that is formed when a H atom is electrically attracted to an electronegative atom (O or N)

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47
Q

how many H bonds can there be in a molecule?

A

100s or 1000s

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48
Q

what are valence electrons?

A

the electrons in the outermost shell

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49
Q

what is ignored in calculations of atomic mass?

A

electrons

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50
Q

what are cations?

A

ions that have a net positive charge

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51
Q

what are anions?

A

ions with a negative charge

52
Q

what is a free radical?

A

a molecule containing an atom with a single unpaired electron in its outer shell

53
Q

what type of molecule is water?

A

polar

54
Q

in a water molecule, the o and h have what charges and why?

A

the o has a partial negative charge because it is electronegative
the h has a partial positive charge because it’s electrons spend more time near the O

55
Q

how can a molecule dissolve in water?

A

It has to be ellectrically attracted to the water molecule ( polar or charged)

56
Q

inside a water molecule how are they connected?

A

by covalent bonds and then there are hydrogen bonds between the molecules

57
Q

if one end of a polar molecule has a partial positive charge it will be attracted so what?

A

the partial negative end on the o of the water

58
Q

if one end of a polar molecule has a partial negative charge, it will be attracted to what?

A

the partial positive on the h of water

59
Q

what kind of molecules dissolve in water?

A

charged ions
charged molecules
polar molecules

60
Q

NA+ is attracted to what in water?

A

the partial negative on the O in water

61
Q

Cl- is attracted to the what in water?

A

the partial positive charge on the H in water

62
Q

the water surrounds the molecules to…

A

dissolve them

63
Q

what are hydrophilic molecules?

A

molecules that can dissolve in water

64
Q

what does hydrophilic mean?

A

water loving

65
Q

hydrophilic molecules are usually

A

charged or polar

66
Q

in a cell, where do hydrophilic molecules usually dissolve?

A

the cytoplasm because it is mainly water

67
Q

are hydrophilic molecules soluble?

A

yes

68
Q

what are hydrophobic molecules?

A

molecules that can’t dissolve in water

69
Q

what does hydrophobic mean?

A

water fearing

70
Q

hydrophobic molecules are normally

A

nonpolar, uncharged, and large

71
Q

where does hydrophobic molecules usually dissolve in?

A

nonpolar solvents

72
Q

in a cell, hydrophobic molecules usually dissolve in the

A

lipid bilayer of a membrane (fatty layer)

73
Q

what is an amphipathic molecule?

A

has one polar/charged end and one nonpolar/hydrophobic end

74
Q

why do hydrophobic parts of the molecule cluster together in an amphipathic molecule?

A

so they minimize exposure to water

75
Q

hydrophilic parts of the amphipathic molecule are attracted to

A

water

76
Q

each end of an amphipathic molecule has different

A

Properties

77
Q

what is a solute?

A

substances dissolved in a liquid

78
Q

what is a solvent?

A

the liquid in which the substance is dissolved

79
Q

what is a solution?

A

a liquid (solvent) containing dissolved substances (solute)

80
Q

what is an aqueous solution?

A

a solution made with water

81
Q

what type of solution is in a cytoplasm?

A

aqueous

82
Q

salt is the solute
water is the solvent

A

saline solution

83
Q

what is cohesion?

A

water molecules are attracted to other water molecules

84
Q

what is adhesion?

A

water molecules are attracted to charged surfaces

85
Q

cohesion and adhesion will cause what in the surface of water?

A

a curve

86
Q

why can water interact with charged surfaces?

A

it has a partial negative and positive

87
Q

water can partially dissolve into

A

ions

88
Q

when water partially dissolves, what form are the particles in?

A

ionized and hydroxide ions

89
Q

what is an acid?

A

a substance that releases H+ ions when it dissolves in water

90
Q

what is a strong acid?

A

completely dissolves into its ions (HCl->H+,Cl-

91
Q

what is a weak acid?

A

partially dissociates into its ions and some stays in its neutral form ( H2CO3-> H+, HCO3)

92
Q

what increases the H+ concentration of a solution?

A

an acid

93
Q

acids solution have a what concentration of H+?

A

high which results in low ph

94
Q

what is a low ph?

A

<7

95
Q

what is a base?

A

a substance that releases OH- ions when it dissolves in water

96
Q

what is a strong base?

A

completely dissociates into its ions (NaOH-> Na+, OH-)

97
Q

what is a weak base?

A

will partially dissociate in water (NH3+H2O <-> NH4+OH-

98
Q

a weak base is normally an

A

organic base

99
Q

there is an always an uncharged form and charged form in what?

A

weak bases and acids

100
Q

what decreases the H+ concentration of a solution?

A

base

101
Q

H+ from water binds to the substance to make what?

A

a positive charged ion

102
Q

basic solutions have what type of concentration of H+

A

low which results in high ph

103
Q

what is a high ph?

A

> 7

104
Q

what is a ph scale?

A

a measure of how acidic or basic a substance is

105
Q

A ph scale is expressed as what?

A

the negative logarithm of the H+ concentration

106
Q

what ph does pure water have?

A

7

107
Q

do alkaline and basic mean the same thing?

A

yes

108
Q

the higher the H+ concentration, what happens to the ph?

A

lower

109
Q

acidic solutions have what type of ph?

A

low (<7)

110
Q

the lower the H+ concentration, what happens to the ph?

A

higher

111
Q

what ph do alkaline or basic solutions have?

A

High (>7)

112
Q

the row on the periodic table shows what?

A

of electrons shells

113
Q

the column on the periodic table shows what?

A

of electrons in the outer shell

114
Q

can a substance be a molecule and an compound?

A

yes
NaCl, CO2

115
Q

explain the trend of electronegatity

A

less-> more

more
^
less

    more
  / less
116
Q

what is nonpolar?

A

less than 0.4

117
Q

what is polar?

A

0.4-0.8

118
Q

what is ionic?

A

more than 0.8

119
Q

what can’t denature an enzyme?

A

cold

120
Q

NaCl is what type of bond

A

Ionic

121
Q

LiF are connected by what bond?

A

Ionic

122
Q

NH3 is a molecule connected by which bond as is H2O. Can these two molecules create H bonds between one another?

A

polar covalent, yes

123
Q

Phosphate groups have what charge?

A

negative

124
Q

is amino group acidic or basic?

A

Basic

125
Q

Is carboxyl an acid or base?

A

Acid

126
Q

Why is carbon a great component of organic molecules?

A

forms polar bonds, forms nonpolar bonds, has 4 electrons in the outer shell

127
Q

is hydraphilic charged or uncharged?

A

charged