Test 2 Flashcards
1
Q
sterilization
A
destruction of all forms of microbial life
2
Q
examples of sterilization
A
boiling and incineration
3
Q
disinfection
A
destructions of disease-causing micoorganism
4
Q
examples of disinfection
A
bleach
5
Q
antisepsis
A
disinfection safe for use on human tissues
6
Q
examples of antipsis
A
iodine and peroxide
7
Q
sanitize
A
microbial control to public health standards
use of sanitizers prevents epidemics
8
Q
decontaminate
A
make safe to handle
9
Q
-cide
A
denotes killing
10
Q
-stat
A
denotes inhibition
11
Q
pasteurization
A
heat treatment of food to prevent spoiling and kill certain microbial pathogens
12
Q
what does pasteurization kill
A
vegetative bacteria, not endospores
13
Q
preservation
A
any physical or chemical treatment of food that inhibits microbial growth and spoilage
14
Q
examples of preservation
A
refrigeration, radiation, low pH, chemicals, salting, drying
15
Q
microbial factors
A
microorganisms vary in susceptibility to killing and are ranked in seven groups. log-phase bacteria are more susceptible to killing, stationary are more resistant
16
Q
environmental factors
A
temperature, pH, and presence of organic matter surrounding and protecting the microorganisms
17
Q
ranking of microorganism in resistance to killing
A
bacterial endospores
fungal spores
mycobacteria
naked viruses (non-lipid coated)
fungi
bacteria
lipid-coated viruses
18
Q
rate of death
A
under constant conditions is constant and logarithmic
19
Q
how does dry heat kill microbial
A
oxidizes or burns the cell components
20
Q
how does moisture heat kill microbial
A
hydrolyzes chemical bonds (faster than oxidation
)
21
Q
positive features of killing with heat
A
effective, fast, reliable, cheap, non-toxic
22
Q
negative features of killing with heat
A
heat or moisture may damage some products
23
Q
how does the autoclave kill with moist heat
A
sterilizes (kills endospores
uses steam under pressure
uses 121 degrees at 15 pounds per square inch for 15 min.
items get wet
24
Q
who discovered pasteurization
A
louis pasteur
25
how does pasteurization kill microorganisms
uses combination of heat and tike to selectively kill them
food becomes safe to heat but not sterile
26
what are the three types of pasteurization
low temp long time: 62 C for 30 min
high temp short time: 72 for 15 sec.
ultra high temp: 140 C for 3 sec.
27
examples of dry heat
hot air oven: 170 C for 2 hours, used on items that wont burn
incineration: for bacteriological loops, bunson burners, commercial products
28
filtration
cellulose filters have pores smaller than microorganisms: air or fluid pass through to filter
29
where are disinfectants registered
EPA
30
where are sterilants registered
FDA
31
what system is used for disinfectants in hospitals
spaulding system (after Earle H. Spaulding)
32
sterilants
produce sterility, for critical items
33
high-level disinfectants
kill all pathogens for semi-critical
34
intermediate-level disinfectants
kill mycobacteria and below on killing scale
35
low-level
disinfectants kill less resistant microorganisms, for non critical items
36
how should chemicals be used
according to directions/instructions for use
37
common alcohols
ethanol and isopropanol
38
how are alcohols used
in small amounts as antiseptics (which are flammable)
39
what do alcohols do
dissolve lipids and disrupt membranes (proteins)
40
how are alcohols usually concentrated
70% in water; more powerful are 100%
example, hand sanitizer and wipes
41
common halogens
iodine and chlorine
42
how to halogens work
oxidize protiens
43
what is the concentration of chlorine
0.5 ppm in water = bleach
44
example of a halogen
betadine before surgery
45
iodine
iodine is a tincture (with alcohol) or idophor (a chemical that controls the release of halogens)
46
what do phenol and phenolics do
damage plasmic membrane
47
do phenol and phenolics have residual activity on surfaces
yes
48
where is phenol and phenolics used most
operating rooms because they can damage some materials
49
how do aldehydes act
inactives proteins and DNA
50
examples of aldehydes
formaldehyde and glutaraldehyde
51
what are aldehydes used for
as a general purpose high-level disinfectant
52
is aldehydes classified as hazardous
yes
53
how do quaternary ammonium compounds work
disrupt the cell membrane
54
what is the general purpose of quaternary ammonium compounds
is a low-level disinfectant, applied with a squirt bottle and left on for 10 miin
55
how do metals work as a chemical
combine with -SH groups, denature proteins
56
examples of metals as a chemical
silver nitrate ointments, mercury, copper
57
where are metals commonly used
burns, dosen't sting of irritate skin
58
ethylene oxide gas
denatures proteins and DNA
used for some heat sensitive hospital instruments
59
plasma sterilizers
generate superoxide radicals in vapor form
can replace autoclaves in some applications but not others
60
ionizing radiation
destorys DNA
gamma and x-ray
used for foods and some hospital supplies
61
UV light
damages DNA
used for clean surfaces and in air ducts
used in some situations to kill TB
does not penetrate or bend around corners
62
chemicals as preservation products
germicidal chemicals can be added to products that are not consumed
benzoic, sorbic, and propionic can be used in food safe to eat, reduces need for refrigeration
63
temperature as preservation products
refrigerator and freezer
64
reducing water available as a preservation product
adding salt or sugar
drying or freeze drying
65
organic catalysts
enzymes
66
what are enzymes
proteins which speed up rate of chemical reactions by lowering activation energy. the chemical bond is formed or broken at the enzyme's active site
67
what are small non-protein molecules that help the reaction and that enzymes may require
coenzymes
68
how are enzymes made and controlled by
DNA
proteins come from RNA and RNA comes from DNA
69
can we use enzymes to identify bacteria
yes
70
what do enzyme rates depend on
temperature and pH
71
what do regulatory molecule do
turn on and off the enzyme
72
how can enzymes be competitively inhibited
substrates that are similar interfere with each other at the active site (some antibiotics work this way)
73
the chemical reactions that take place in a cell
metabolism
74
synthesize larger molecules and components from smaller ones, requires energy and small chemical components
anabolic reactions
75
take larger molecules and break them up, releasing the energy in their chemical bonds.
catabolic reactions
76
how does bacteria vary in their metabolism
ability for substrates to get in varies and presence of the right enzymes varies
77
what does the efficiency of metabolism vary on
substrate and pathway
78
what are sequential enzymatic reactions that result in a product and can be linear or cyclical
metabolic pathways
79
can we identify bacteria based on their metabolism
yes
80
is metabolism high controlled
yes
81
what is stored and transferred in chemical bonds
energy
82
how many breakable phosphate bonds does ATP have
2
83
what releases energy
removing a phosphate in ATP
84
what does NAD/NADP
store and release hydrogen atoms
85
adding a H is
reduction
86
removing an H is
oxidation
87
what connects anabolic and catabolic pathways when they work concurrently in the cell
ATP and NAD, energy from the catabolic feeds the anabolic
88
common bacteria pathways
glycolysis, krebs, pentose phosphate
89
with these, bacteria can catabolize food and make the precursors for things they need
sugars for carbohydrates
amino acids for proteins
nucleic acids for RNA and DNA
90
most common catabolic pathway
glycolysis
91
what do glycolysis start with
glucose
92
most common energy source
glucose
93
what does glucose split into in glycolysis pathways
3-carbon molecules on pyruvate
94
yield of glucose
2 ATP and 2 NADH
95
metabolism of pyruvate without oxygen
fermentation
96
what does pyruvate convert to
lactic acid, acetaldehyde, other mixed organic compounds
97
can end products of fermentation unique to each species and can they be used to identify bacteria
yes
98
another name for krebs cycle
tricarboxylic acid or respiration
99
krebs cycle is
an aerobic reaction (requires oxygen)
100
what does krebs cycle start with
pyruvate from glycolysis
101
during krebs cycle what does the rest of the energy from pyruvate become
- three CO2 and water
- releases almost all the energy in the glucose
- captures enough energy for 15 ATP
- more efficient but requires oxygen
102
what is an alternative energy source to glycolysis
pentose phosphate pathway
103
what is pentose phosphate pathway important for
supplying 4-carbon and 5-carbon molecules to other pathways
104
what is performed by algae and photosynthetic bacteria
photosynthesis
105
what captures light energy which is used to make fructose from atmospheric CO2 and water
photosynthesis
106
another name for the calvin cycle
photosynthesis
107
what is a DNA molecules structure
double helix
108
what does a subunit of DNA consist of
nucleotides, a deoxyribose sugar, a phosphate, and a pryimidine or purine base.
109
what are strands of DNA
chains of sugars and phosphates held by covalent bonds, with the bases pointing outward
110
what are the two strands of DNA held together by
weaker hydrogen bonds between the bases and are twisted
111
what determines the other strand of DNA
the sequence of the original strand
112
nitrogenous bases are
complementary (adenine bonds to thymine, guanine with cytosine)
113
where is the deoxyribose missing
the -OH on the second carbon
114
how many rings does purine have
2
115
how many rings does pyrimidines have
1
116
where is pentoses connected to on DNA
between 3 and 5 carbon, connected by strong covalent phosphate bones
117
where is the base attached to DNA
1 carbon and sticks out from the chain of pentose
118
how do the chromosomes line up in two single strand
opposite directions (antiparallel)
119
base pairing
the bases form hydrogen (weak) bones with each other
120
complementary base pairing
the pyrimidines bind to the purines
thymine always binds with adenine using 2 hydrogen bonds
cytosine always binds with guanine using three hydrogen bonds
121
what does the helix twist into
supercoil (takes up less space)
122
what shape is the DNA molecule in bacteria
ends are connected and is one circular chromosome
123
what is the spot on the circle where replication always starts
origin of replication
124
what does DNA replication result in
one exact copy of the original DNA chromosome
125
what sits on the origin of replication, unwinds the helix, separates the hydrogen bonds of the base pairs, and adds new nucleotides to the template strand
DNA polymerase complex
126
what direction does DNA replication proceed in
both directions
127
when is replication complete
when the two forks meet
128
what does semiconservative mean
describes replication because it results in two chromosomes, each with one new strand and one old strand in its helix
129
are both strands replicated continuously
no, one strand is done continuously and the other is done discontinuously because the enzymes van only go in one direction
130
what is used to make RNA
DNA
130
what is used to make proteins
RNA
131
what is the purpose of DNA
to make and control the making of protein
132
making RNA from DNA
transcription
133
making proteins from RNA
translastion
134
what determines everything that happens in the cell
proteins (as structural or enzyme proteins)
135
what shape is RNA
single strand
136
what does RNA use instread of thymine
uracil
137
what are the three RNA
messenger, ribosomal, transfer
138
messanger RNA
forms an exact copy of DNA
139
ribosomal RNA
helps from ribosomes
140
transfer RNA
brings the amino acids to the ribosome
141
genes
DNA coding regions, a DNA sequence that produces one protein
142
what is a promotor
just prior to the coding region allows transcription to be turned on or off
143
terminator
stops transcription
144
what does RNA polymerase enzyme do
make a new mRNA strand from one of the DNA strands
145
RNA polymerase binds to the DNA regulatory region and starts making RNA at the beginning of the coding region
initiation
146
The polymerase moves along the DNA strand, adding RNA nucleotides together to make mRNA complementary to the DNA template
elongation
147
the polymerase comes to the end of the gene, hits the stop codon, stops and falls off
termination
148
what are linear polymers made from 20 different amino acids
proteins
149
what codes for one amino acids
a set of three nucleotides
150
what is making RNA and proteins called
gene expression
151
each of the 20 amino acids is coded for by a set of three consecutive RNA nucleotides called what
codon
152
stop codons
UAA, UAG, UGA
153
start codon
AUG
154
what does the cell make proteins from linear single-stranded mRNA using
genetic code
155
how much energy is required for translation
90%
156
uses transfer RNA and ribosomes:
-the cell has 20 unique tRNA; one for each amino acid
-each tRNA holds its amino acids on one end and has a complementary codon on the other end that sits onto the mRNA
157
large molecules with two parts:
- ribosomal RNA
- proteins
ribonucleoprotien
158
small subunit that holds the mRNA being translated
ribosome
159
what does the large subunit of ribosomes do
aligns the tRNA holding amino acids
160
how are bacterial ribosomes different
they are smaller
161
what holds the mRNA single strand
ribosomes
162
what rides in the groove between the small and large subunits of ribosome particles
mRNA
163
how many binding sites for tRNA does ribosomes have
2
164
what kind of bond is formed when the ribosome grabs the tRNA that it needs for its first two codons and holds them next to each other
peptide bond
165
what holds the first tRNA; the anticodon bound to the corresponding mRNA codon
peptide site
166
what accepts the incoming tRNA that it needs for its next codon
acceptor site
167
proteins from one amino acids at a time
the peptide site tRNA transfers it's amino acid to the acceptor tRNA, then falls off, the protein now has one more amino acid and is still sitting in the acceptor site
168
what moves forward on codon during elongation of RNA
ribosome
169
when what is formed, does a protien lengthen by on amino acid
peptide bond between new amino acid
170
bacterial translation is
fast
171
are all proteins functional after they come off the ribosome
no some are not and they need to be folded into their proper 3-D shape by chaperone enzymes and some need to be transported across the cell membrane
172
what do regulatory mechanisms do
turn synthesis of protein on or off at the gene level.
173
what is the region called where all the enzymes of one pathway are
promotor region
174
polycistronic
can code for more that one protein on one mRNA
175
cistron
RNA that codes for one protein
176
introns
only in eukaryotic cells; non-coding RNA that needs to be cut out
177
repressor
end product of a pathway that turns off transcription of the genes for all the pathway enzymes at the regulatory site when enough product has been produced.
178
inhibitor
the end product of a pathway goes back and turns off the first enzyme in the pathway
179
inducer
the presence of the nutrient that needs to be metabolized that turns on the regulatory region, allowing the genes to be turned on and enzyme made only when they are needed
180
enzymes that are normally off but can be turned on are
inducible
181
enzymes that are always on
constitutive
182
when a cells in a population of bacteria communicate with each other to coordinate the metabolism of the population as a group
quorum setting
183
an external signal sensed by bacteria
signal transduction
184
the study of the DNA sequence of an orangism
genomics
185
what may be useful in the design of new drugs
genomics
