Unit 1 Flashcards
1
Q
What are the 4 common characteristics all cellular life shares?
A
DNA genome
cytoplasm
ribosomes
plasma membrane
2
Q
What does eukaryote mean?
A
true nucleus
3
Q
What kind of organelles do eukaryotes have?
A
membrane-bound
4
Q
What is the eukaryote genome made of?
A
double-stranded DNA and multiple, linear chromosomes
5
Q
Can eukaryotes be single-celled and multicellular?
A
yes
6
Q
Can some eukaryotes have a cell wall?
A
yes
plants and protists
7
Q
What does prokaryote mean?
A
before nucleus
8
Q
Do prokaryotes have membrane-bound organelles?
A
no
9
Q
What is the prokaryote genome made of?
A
double-stranded DNA and a single, circular chromosome
10
Q
Are prokaryotes all single cells?
A
yes
11
Q
Do all prokaryotes have a cell wall?
A
yes
12
Q
What does eubacteria mean?
A
true bacteria
13
Q
What does eubacteria have?
A
peptidoglycan (makes up cell wall)
14
Q
What characteristic do eukaryotes share with eubacteria?
A
same physiological conditions
15
Q
What are archaebacteria called?
A
extremophiles because they inhabit harsh environments (not all)
16
Q
What characteristics do eukaryotes share with archaebacteria?
A
they both have histone proteins
they share similar molecular mechanisms
17
Q
What is a genome?
A
instructions for a cell/organism, all of the genes in an organism
18
Q
What is cytoplasm?
A
interior chemical makeup of the cell
19
Q
What do ribosomes do?
A
make proteins
20
Q
What does the plasma membrane do?
A
provides protection for the cell
21
Q
What does the rRNA sequence comparison help us determine?
A
how related different species are
22
Q
What is the phylogenic tree?
A
shows relationships between eubacteria, archaebacteria, and eukaryotes
23
Q
What are the characteristics archaebacteria have on the phylogenic tree?
A
evolutionary intermediate in between eubacteria and eukaryotes
24
Q
Are archaebacteria more closely related to eukaryotes or prokaryotes?
A
eukaryotes
25
What is a supercoil?
the additional twisting or coiling of the DNA double helix
26
What is the nucleosome?
a DNA-protein complex that's the basic unit of chromatin
27
What are histones?
A type of protein found in chromosomes
28
What is chromatin?
DNA and histone proteins combined
29
What are chromosomes made of?
chromatin
30
Do eubacteria have chromatin?
no because they have no histone proteins
31
What are the most abundant elements found in living organisms?
Hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur
32
What is cohesion?
same molecules attracted to each other
33
What is adhesion?
one substance attracted to another substance
34
Is water more dense as a liquid or solid?
liquid
35
What kind of capacity does water have for absorbing energy?
high (stabilizes temps)
36
How does water minimize change in pH?
acts as a proton donor and acceptor
37
What is the law of mass action?
the rate of a reaction is proportional to the product of the concentrations of each reactant
38
What are van der waals interactions?
weak attractions or interactions between molecules
39
Do molecules have to be very close to each other for van der waals interactions to happen?
yes
40
How many calories are in waters heat capacity?
1 calorie/gram C
41
What is the sphere of hydration?
hydrogen bonds with a surrounding layer of water molecules
42
When does dissociation occur?
when atoms or groups of atoms break off from molecules and form ions.
43
What is surface tension?
the capacity of a substance to withstand rupturing when placed under tension or stress.
44
What are hydrocarbons?
organic molecules consisting entirely of carbon and hydrogen
45
What are aliphatic hydrocarbons?
linear chains of carbon atoms
46
What are aromatic hydrocarbons?
closed rings of carbon atoms with alternating single and double bonds.
47
What are isomers?
molecules that share the same chemical formula but differ in the placement (structure) of their atoms and/or chemical bonds
48
What are geometric isomers?
similar placements of their covalent bonds but differ in how these bonds are made to the surrounding atoms
49
What are Enantiomers?
molecules that share the same chemical structure and chemical bonds but differ in the three-dimensional placement of atoms
50
What are functional groups?
groups of atoms that occur within molecules and confer specific chemical properties to those molecules.
51
Do ions have a full or partial charge?
full
52
Can water molecules ionize?
yes
53
What does pH measure?
free. H+ or -OH
54
What does a low pH mean?
acidic ((high concentration of H+)
55
What does a high pH mean?
basic (high concentration of -OH)
56
What are stacking forces?
Hydrogen bonds within a molecule that increase the strength of the hydrogen bond
57
What kind of covalent bond is the strongest?
triple bond
58
Are covalent bonds or ionic bonds more common amongst living organisms?
covalent
59
Do bonds take energy to break?
yes
60
Is nonpolar hydrophobic or hydrophilic?
hydrophobic
61
Is polar hydrophobic or hydrophilic?
hydrophilic
62
What are the 4 classes of macromolecules that make up all parts of the cell?
Proteins
Nucleic acids
Carbohydrates
Lipids
63
What elements will always be nonpolar when they are bonded together?
carbon and hydrogen
All other elements will be polar when they are bonded together (like Oxygen and Sulfur)
64
What is a monomer?
amino acid
65
What does a peptide bond occur between?
occurs between carboxyl group of the first amino acid and the amino group of the second amino acid
66
What is a dehydration synthesis reaction (condensation reaction)?
lose a molecule of water to synthesize (form) a bond
67
What are the functions of proteins?
make up cell machinery, enzymes are proteins, make up the cytoskeleton in cells
68
What elements are in carbohydrates?
carbon, hydrogen, and oxygen
69
What shapes do carbohydrates come in?
linear structures and ring structures
70
What are 3 groups of carbohydrates?
Monosaccharides, disaccharides, polysaccharides
71
What does monosaccharide mean?
1 sugar
72
What does disaccharide mean, what is it made up of, and what kind of reaction is it?
2 sugars
made up of 2 monosaccharides joined together by a condensation reaction
73
What does polysaccharides mean, what are they made up of, and what kind of reaction are they formed through?
many sugars
polymers are formed by combining many monosaccharide molecules through condensation reactions
74
What structures are in monosaccharides?
glucose, fructose, galactose
75
What structures are in disaccharides?
sucrose (glucose and fructose), lactose (galactose and glucose)
76
What structures are in polysccharides?
cellulose, starch, glycogen
77
What kind of molecule is cellulose?
structural
78
What are the functions of carbohydrates?
Make up the cell wall in prokaryotes
Serve as a source of energy as well as storing energy
79
What are nucleic acids?
polymers made up of nucleotides
80
What are nucleotides made up of?
5 carbon sugar, nitrogenous base, phosphate group
81
What do nucleic acids form and what kind of reaction is this?
Form chain links through a dehydration synthesis
82
How do nucleic acids polymerize?
through a phosphodiester bond
83
RNA is the first step of...
gene expression
84
Are most RNA molecules translated as proteins?
no
85
Can RNA function as an enzyme?
yes
86
What are lipids composed of?
hydrocarbons
87
What do lipids do?
Make up cell membranes
Provide waterproofing for aquatic animals and plants
88
Is there a common bond type in lipids?
no
89
Are monosaccharides nonpolar or polar?
polar
90
What is the amino acid structure?
The alpha carbon is bonded to a hydrogen atom, amino group, carboxyl group, and an R group
91
How many different R groups are there?
20
92
Amino acids exist in the cell as...
ionized molecules
93
When do amino acids ionize?
when they are in water
94
When does the amino group act as a base?
when it accepts H+
95
When does the carboxyl group act as an acid?
when it releases the H+
96
Are peptide bonds ionic or covalent bonds?
covalent
97
What kind of reaction is a peptide bond?
condensation reaction/dehydration synthesis because a water molecule is lost
98
Peptide bonds link together to form...
polypeptide chains
99
What is the amino terminus of the peptide bond called?
n-terminus
100
What is the carboxyl terminus called in a peptide bond?
c-terminus
101
What kind of electron sharing occurs through carbonyl groups and what does this result in?
unequal electron sharing results in a strong bond, spreading the charge across
102
What do carbonyl groups give the peptide bond?
double bond character
peptide bonds are more rigid because of this
103
Can the other sides of carbonyl groups of peptide bonds have rotation?
yes
104
What is the Protein primary (1°) structure?
Order of the amino acids in the chain
Simplest structure of proteins
Proteins dont exist in this state
105
What is the Protein secondary (2°) structure?
Alpha helices
Beta pleated sheets
Folding of the protein chain due to interactions between amino acids in the backbone
Due to intermolecular interactions between amino acids
106
What is the Protein tertiary (3°) structure?
noncovalent bonds formed between nonadjacent amino acids
Highest level of individual proteins
Due to R-group interactions
107
What is the Protein quaternary (4°) structure?
Multiple proteins bind to form a structure
108
What is a glycosidic bond?
bond that links the 2 monosaccharides
109
What are oligosaccharides?
Molecules with 3-10 sugar units
110
What are true polysaccharides?
Molecules containing more than 11 sugar units
111
Cellulose is the major energy component of cell walls in...
plants
112
Starch is the main energy storage material in...
plants
113
Glycogen is the main energy storage material in...
animals
114
What are the 5 common polysaccharides?
Chitin in fungi and arthropods
Cellulose
Peptidoglycan
Starch glycogen
115
What is chitin?
Contains nitrogen
makes up cell walls in fungi
Makes up the exoskeleton of arthropods
116
What is the purpose of peptidoglycan, what is it made up by, what are linked together, and what kind of pattern is formed?
Makes up the cell wall in eubacteria
Made up of polysaccharides and oligopeptides
Individual peptide chains link together polysaccharide chains
Forms a mesh pattern referred to as cross-linking
117
What is starch glycogen?
Energy storage molecule
118
What are beta pleated sheets and alpha helices and what are bonds formed between?
hydrogen bonds forming between carbonyl and amino groups of amino acids through the backbone
119
How does the tertiary structure form?
forms through hydrogen bonds, ionic bonds, dipole-dipole interactions, and London dispersion forces
120
How does penicillin kill bacterial cells?
Transpeptidase forms bonds between amino acids is inhibited by penicillin. Penicillin binds to the transpeptidase enzyme and inhibits it. When cell tries to divide it bursts
(It inhibits the cross-linking of peptidoglycan in bacterial cell walls)
121
Why is the ionized form of an amino acid significant for biological systems?
it allows for the formation of complex protein structures
122
What are the 4 major categories of amino acid side chains?
nonpolar hydrophobic
polar uncharged hydrophilic
polar charged (+) hydrophilic
polar charged (-) hydrophilic
123
What is an important chemical feature of nonpolar hydrophobic side chain?
lack of polar bonds, little to no electronegative atoms
124
What is an important chemical feature of polar uncharged hydrophilic side chain?
presence of electronegative atoms like oxygen or nitrogen, can form hydrogen bonds with water molecules
125
What is an important chemical feature of polar charged (+) hydrophilic side chain?
the presence of a positively charged nitrogen atom within its structure
126
What is an important chemical feature of polar charged (-) hydrophilic side chain?
the presence of a functional group with a net negative charge
127
What is the structure of an IONIZED amino acid?
alpha carbon bonded to a hydrogen ion, NH3, R group, C double bonded to an O and single bonded to an O-
128
Explain how electron sharing contributes to the high stability of peptide bonds
a partial double bond character is created on the carbonyl, making it unable to rotate
129
Why is cellulose so rigid?
long chains of glucose molecules linked together by strong hydrogen bonds
130
What is the 5-carbon sugar found in RNA? What is the hydroxyl group bonded to?
ribose, 2' carbon
131
What is the 5-carbon sugar found in DNA? What is the hydrogen atom bonded to?
deoxyribose, 2' carbon
132
How many nitrogenous bases are found in nucleic acids? What are their names?
5
cytosine, uracil, thymine, guanine, adenine
133
What do pyrimidines consist of and what is their structure?
cytosine, uracil (RNA, thymine (DNA)
6 member ring
134
What do purines consist of and what is their structure?
guanine, adenine
5 member ring fused to a 6 member ring
135
Is uracil only find in RNA?
yes
136
What are phosphodiester bonds?
covalent bonds formed through a condensation reaction
137
What does the 3' hydroxyl group join? What does this do?
phosphate group on the 5' carbon, gives nucleic acids polarity
138
What kind of backbone do nucleic acids have?
sugar-phosphate backbone
139
What makes up the sugar-phosphate backbone?
Sugar of one nucleic acid linked to a phosphate of another nucleic acid
140
What do complementary base pairs do?
hold DNA strands together in the double helix
141
Hydrogen bonds are formed between what in nucleic acids?
nitrogenous bases
142
Can any 2 nitrogenous base form hydrogen bonds with each other?
yes
143
Guanine is always paired with...
How many hydrogen bonds are formed?
cytosine
3
144
Adenine is always paired with...
How many hydrogen bonds are formed?
thymine
2
145
1) What is antiparallel orientation?
2) What does the 5' end pair up with?
3) Why is it called "antiparallel"?
1) in double-stranded DNA, 2 strands bind together in an antiparallel fashion
2) 3' end of other chain
3) because strands are running in opposite directions
146
What is the primary structure of nucleic acids?
Sequence of bases, A G C T
147
1) What is the secondary structure of nucleic acids?
2) How does RNA form secondary structures?
3) What is the secondary structure of DNA?
1) Formed through hydrogen bonding between nitrogenous bases in 2 strands of DNA
2) still forms a secondary structure because hydrogen bonds can form between nitrogenous bases within a single-strand
3) double-stranded helix
148
1) what is the tertiary structure of nucleic acids?
2) what does DNA wrap up with?
3) what do hydrogen bonds in RNA from between?
1) Addition twisting and folding that takes place
2) DNA wraps up with histone proteins
3) between nonadjacent parts of the molecule that forms 3-dimensional shapes
149
What are isoprenes linked into?
branch hydrocarbon chains called isoprenoids
150
What are fatty acids?
unbranched hydrocarbon chains joined to a hydroxyl group
151
What is a saturated fatty acid?
only single bonds between the carbons
152
What is an unsaturated fatty acid?
one or more double bonds between the carbons
There is a bend
153
What are lipids characterized by?
their insolubility in water instead of a shared chemical structure
154
What are the 3 types of lipids found in cells?
Fats
Steroids
Phospholipids
155
1) What are fats?
2) what is their function?
1) nonpolar molecule composed of three hydrocarbon chains linked to glycerol
2) Function in energy storage
156
1) What are steroids?
2) what are their functions?
1) consist of a 4-ring structure, different steroids have different functional groups attached
2) cell membranes and as a signaling molecule
157
1) What are phospholipids?
2) What are their functions?
1) glycerol linked to a phosphate group and 2 hydrocarbon chains. The phosphate is bonded to a small organic molecule (charged or polar)
2) store chemical energy, act as pigments, signaling molecules, waterproof coating on leaves and skin and act as vitamins, cell membranes
158
What is the phospholipids bilayer called?
amphipathic because it functions as hydrophobic and hydrophilic
159
What is the hydrophilic part of the phospholipid bilayer?
Head
interacts with water
160
What is the hydrophobic part of the phospholipid bilayer?
tail
tails interact with one another
161
What is the nitrogenous base in a nucleotide attached to?
1'carbon on the 5-carbon sugar
162
Is RNA or DNA more stable?
DNA
163
The monomer for nucleic acid is a...
nucleotide
164
How do phosphodiester bonds form?
3' carbon bound to a hydroxyl group, nucleotide links phosphate group to 5' carbon, a water molecule is lost
165
Is DNA negatively or positively charged?
negatively
166
Where do nitrogenous bases stick out from? What bonds do they form?
sugar-phosphate backbone and form hydrogen bonds
167
In simple terms what is the primary, secondary, and tertiary structure of DNA?
primary: sequence of bases
secondary: twisting of double helix
tertiary: double helix twists around histone proteins
168
In simple terms what is the primary, secondary, and tertiary structure of RNA?
primary: sequence of bases
secondary: single-strand folds to form a double-helix
tertiary: 3D structure is formed
169
Do phospholipids self-orientate?
yes, tails face each other, heads face the water
170
What kinds of bonds are in proteins, carbohydrates, nucleic acids, and fats?
proteins: peptide bonds
carbohydrates: glycosidic bonds
nucleic acids: phosphodiester bonds
fats: no common bonds
