Chap 2 Flashcards
(147 cards)
1
Q
What is the smallest component of a substance that CANNOT be divided into smaller substances without losing its properties?
A
Atom
2
Q
The nucleus contains
A
protons and neutrons.
3
Q
Atoms with different numbers of neutrons in their nuclei are called
A
isotopes.
4
Q
How many electrons can be held in the second shell?
A
8
5
Q
An isotope of oxygen has an atomic number of 8 and an atomic weight of 18. How many neutrons does it have?
A
10
6
Q
Which type of bond is weak and does NOT bind atoms into molecules?
A
Hydrogen bond
7
Q
The number of extra or missing electrons in an atom’s outermost electron shell is called the atom’s
A
valence
8
Q
A bond formed from the attraction between ions of opposite charge is called a(n)
A
ionic bond
9
Q
A molecule that contains at least two different kinds of atoms is called a(n)
A
compound
10
Q
Which of the following is formed by the sharing of electrons between atoms to fill an electron shell?
A
Covalent bond
11
Q
Water has an unequal distribution of charges and is called a(n)
A
polar molecule
12
Q
Which one of the following does NOT correctly describe inorganic compounds?
a)Usually small
b)Structurally simple
c)Contain carbon
d)Include salts, acids, and bases
A
Contain carbon
13
Q
A compound that helps keep the pH from changing drastically is
A
Buffer
14
Q
MOST microbes grow best at a pH from
A
6.5-8.5
15
Q
A substance that dissociates into H+ and Cl– in water is an example of a(n)
A
acid
16
Q
In a decomposition reaction (also known as hydrolysis), sucrose can be broken down into
A
glucose and fructose
17
Q
The following is an example of what type of reaction? AB + CD → AD + BC
A
Exchange reaction
18
Q
Endergonic reactions ALWAYS
A
absorb more energy than they release.
19
Q
In a synthesis reaction,
A
atoms, ions, or molecules are combined to form a larger molecule.
20
Q
In a decomposition reaction
A
a larger molecule is broken down into smaller parts.
21
Q
Which of the following are the “building blocks” of proteins?
A
amino acids
22
Q
Which of the following are purines?
A
Adenine and guanine
23
Q
Which of the following nitrogenous bases is NOT found in an RNA molecule?
A
Thymine
24
Q
Why do saturated fats become solid more easily than unsaturated fats?
A
They are straight chains and pack more tightly together.
25
Glycogen, dextran, and cellulose are examples of
polysaccharides
26
Which level of protein structure refers to the overall three-dimensional structure of a polypeptide chain?
tertiary structure
27
Chemistry
is the study of interactions between atoms and molecules
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the smallest unit of matter and cannot be subdivided into smaller substances
atom
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atoms interact to form
molecules
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negatively charged particles
electrons
31
positively charged particles
protons
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uncharged particles
neutrons
33
Atoms with the same number of protons are classified as the same
chemical element
34
Each different chemical element has a different number of
protons
35
atomic number
: number of protons in the nucleus
36
is the total number of protons and neutrons in an atom
Atomic mass
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of an element are atoms with different numbers of neutrons
Isotopes
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are the most abundant chemical elements in living Organisms.
Hydrogen, carbon, nitrogen, and oxygen
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Electrons are arranged in _______ ________corresponding to different energy levels
Electron shells
40
Atoms form molecules by combining to fill their
outermost shells
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Molecules hold together because the valence electrons of the combining atoms form attractive forces, called
chemical bonds, between the atomic nuclei
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is a molecule that contains two or more kinds of atoms
compound
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The number of protons and electrons are _______ in an atom
equal
44
are charged atoms that have gained or lost electrons
ions
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are atoms that lose electrons and become positively charged ions
cations
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are atoms that gain electrons and become negatively charged ions
anions
47
attractions between ions of opposite charge
ionic bonds
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form when two atoms share one or more pairs of electrons
covalent bonds
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are stronger and more common in organisms than ionic bonds
covalent bonds
50
form when a hydrogen atom that is covalently bonded to an O or N atom is attracted to another N or O atom in another molecule
Hydrogen bonds
51
molecular mass
The sum of the atomic masses in a molecule
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One mole of a substance is
its molecular mass in grams
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The unit of molecular mass is a
dalton (da)
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involve the making or breaking of bonds between atoms
chemical reactions
55
A change in _______ _______ occurs during a chemical reaction
chemical energy
56
reactions that absorb energy
endergonic
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reactions release energy
exergonic
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Occur when atoms, ions, or molecules combine to form new, larger molecules
synthesis reactions
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is the synthesis of molecules in a cell
Anabolism
60
Occur when a molecule is split into smaller molecules, ions, or atoms
decomposition reactions
61
is decomposition reactions in a cell
catabolism
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Are part synthesis and part decomposition
exchange reactions
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The Reversibility of Chemical Reactions
Can readily go in either direction
Each direction may need special conditions
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Organic compounds
always contain carbon and hydrogen; typically structurally complex
65
Inorganic compounds
typically lack carbon; usually small and structurally simple
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important characteristics of water
1.Polar molecule
2. Solvent
3. Hydrogen bonds absorb heat
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Is water organic or inorganic?
inorganic
68
What does it mean for water to be a polar molecule?
Unequal distribution of charges
69
What does it mean for water to be a solvent?
Polar substances undergo dissociation in water, forming solutes
70
Why are hydrogen bonds in water important?
Hydrogen bonds absorb heat
Temperature buffer
71
Acids
Substances that dissociate into one or more hydrogen ions and one or more negative ions
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Bases
Substances that dissociate into one or more hydroxide ions and one or more positive ions
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Salts
Substances that dissociate into cations and anions, neither of which is
H+ or OH-
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The concentration of H+ in a solution is expressed as
pH
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pH formula
pH=-log10[H+]
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Increasing H+ increases
acidity
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Increasing OH- increases
alkalinity
78
Most organisms grow best between which pH?
6.5-8.5
79
Why is the polarity of a water molecule important?
Makes it a good solvent
Gives it ability for hydrogen bonding which lets it absorb a lot of heat
80
carbon skeleton
The chain of carbon atoms in an organic molecule is the
81
bond to carbon skeletons and are responsible for most of the chemical properties of a particular organic compound
functional groups
82
In an aldehyde, C===O is at the end of a molecule, vs a ketone where
in a ketone C===O is internal
83
Identify the functional groups in an amino acid
NH2 amine group
COOH carboxyl group
84
are polymers consisting of many small repeating molecules called monomers
macromolecules
85
Monomers join by
dehydration synthesis or condensation reactions
86
Serve as cell structures and cellular energy sources
Include sugars and starches
carbohydrates
87
Carbohydrates consist of
C, H, and O
88
Formula for carbohydrates
(CH2O)n
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True or false: many carbohydrates are isomers
True
90
Isomers
Molecules with same chemical formula, but different structures
91
Monosaccharides
simple sugars with three to seven carbon atoms
92
examples of common monosaccharides
Glucose and deoxyribose
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are formed when two monosaccharides are joined in a dehydration synthesis
Disaccharides
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Disaccharides can be broken down by
Hydrolysis
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consist of tens or hundreds of monosaccharides joined through dehydration synthesis
Polysaccharides
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Examples of polysaccharides
Starch, glycogen, dextran, and cellulose are polymers of glucose that differ in their bonding and function
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Examples of dissacharides
sucrose, lactose, and maltose.
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Primary components of cell membranes
Consist of C, H, and O
Are nonpolar and insoluble in water
lipids
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Simples lipids
Fats or triglycerides
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Simple lipids contain
Contain glycerol and fatty acids;
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Simple lipids are formed by
formed by dehydration synthesis
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Saturated fat
no double bonds in the fatty acids
103
Unsaturated fat
one or more double bonds in the fatty acids
104
Cis
H atoms on the same side of the double bond
105
Trans
H atoms on opposite sides of the double bond
106
Complex lipids contain
Contain C, H, and O + P, N, and/or S
107
Cell membranes are made of complex lipids called
Phospholipids
108
Structure of phospholipids
Glycerol, two fatty acids, and a phosphate group
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Regions of phospholipids
Phospholipids have polar as well as nonpolar regions
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Four carbon rings with an -OH group attached to one ring
Steroids
111
Part of membranes that keep the membranes fluid
Steroids
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How do simple lipids differ from complex lipids?
simple lipids aka triglycerides contain glycerol and fatty acids and are formed by dehydration synthesis (saturated, unsaturated, cis, trans). complex lipids ARE AMPHIPATHIC and contain c h o (and n or p or S) and are made up of glycerol two fatty acids and a phosphate (phospholipid)
113
Which elements make up proteins?
Made of C, H, O, N, and sometimes S
114
Functions of proteins
essential for cell structure and function
1.Enzymes that speed up chemical reactions
2. Transporters across cell membrane
3. Flagella
4.toxins and cell structures
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subunit of proteins
aminoacids
116
Amino acids contain an alpha-carbon that has an attached:
1. Carboxyl group -COOH
2. Amino group NH2
3.side group
117
Amino acids exist is two stereoisomers
D or L
118
Stereoisomers
stereoisomers are isomers that differ in spatial arrangement of atoms, rather than order of atomic connectivity.
119
Which stereoisomers of aminoacids are most often found in nature?
L-form
120
Peptide bonds
between amino acids are formed by dehydration synthesis
121
Primary structure
Polypeptide chain
122
Secondary structure
occurs when the amino acid chain folds and coils in a helix or pleated sheet
123
Tertiary structure
occurs when the helix or sheet folds irregularly, forming disulfide bridges, hydrogen bonds, and ionic bonds between amino acids in the chain
124
quarternary structure
consists of two or more polypeptides
125
Denaturation occurs when
proteins encounter hostile environments such as temperature and pH, and therefore lose their shapes and functions
126
Conjugated proteins consist of
amino acids and other organic molecules
Glycoproteins
Nucleoproteins
Lipoproteins
127
What two functional groups are in all amino acids?
-COOH & -NH2
128
subunit of nucleic acids
nucleotides
129
components of nucleotides
A five-carbon (pentose) sugar
Phosphate group
Nitrogen-containing (purine or pyrimidine) base
130
Nucleosides components
Pentose
Nitrogen-containing base
131
DNA stands for
Deoxyribonucleic acid
132
Contains deoxyribose
Exists as a double helix
DNA
133
In DNA, Adenine bonds with
Thymine
A is to T
134
In DNA, Cytosine bonds with
Guanine
C is to G
135
how does A bind to T and C bind to G in DNA ?
Hydrogen bonding
136
Order of the nitrogen-containing bases forms
the genetic instructions of the organism
137
Ribonucleic acid
contains
Ribose
138
Is single stranded
RNA
139
Explain the bonding of nucleotides in RNA
Adenine hydrogen bonds with Uracil
A --->U
Cytosine hydrogen bonds with Guanine
C--->G
140
Several kinds of R N A play a specific role in
protein synthesis
141
ATP stands for
Adenosine triphosphate
142
ATP is made of
Made of ribose, adenine, and three phosphate groups
143
Function of ATP
Stores the chemical energy released by some chemical reactions
144
How does ATP release energy?
Releases phosphate groups by hydrolysis to liberate useful energy for the cell
145
Which can provide more energy for a cell and why: A T P or A D P?
Adenosine triphosphate (ATP) can provide more energy for a cell than adenosine diphosphate (ADP) because it has more phosphate groups and a higher-energy bond:
146
Serology
the use of specific antibody binding. Helps hasten diagnosis
147
