exam3 Flashcards
1
Q
Nucleotides have ______ which gives them directionality
A
polarity
2
Q
what prime is bacterial DNA
A
5’-3’
3
Q
What DNA has a one-string structure?
A
pyrimidines
4
Q
What DNA has a double-ring structure?
A
Purines
5
Q
What is the role of bacteria’s genetic material?
A
stores info, replicates, and genetic variation for diversity
6
Q
is it eukaryote or prokaryote if the DNA resides in the cytoplasm?
A
prokaryote
7
Q
is it eukaryote or prokaryote if it has a small genome?
A
prokaryote
8
Q
is it eukaryote or prokaryote if it does not have a plasmid
A
Eukaryote
9
Q
is it eukaryote or prokaryote if it possesses a large coiled circular chromosomes?
A
prokaryote
10
Q
is it eukaryote or prokaryote if the DNA is less compacted?
A
eukaryote
11
Q
is it eukaryote or prokaryote if it contains a lot of non-coding DNA in between genes?
A
eukaryote
12
Q
is it eukaryote or prokaryote if it does not possess operons?
A
Eukaryote
13
Q
is it eukaryote or prokaryote if the DNA wraps around HU proteins?
A
Prokaryote
14
Q
Which genome has 50000 base pairs
A
bacterial genome
15
Q
Which genome has 40000 base pairs in one gene
A
eukaryotic
16
Q
A unit of multiple genes controlled by the same promoter and regulatory region
A
operon
17
Q
What are the 3 RNA products expressed by genes?
A
mRNA, rRNA, tRNA
18
Q
What enzymes are required for prokaryote replication?
A
homologs
19
Q
How does prokaryote DNA replication work?
A
Each strand is template, starts at origin of replication and goes bidirectionally, creating 2 forks. Leading strand synthesizes on long 5-3’, lagging strand synthesizes okazaki fragments that are ligated together
20
Q
What is the job of helicase?
A
Binds oriC and unwinds the double helix
21
Q
What does a primase protein do?
A
Inserts short RNA primer which provides the first 3’ OH for each strand
22
Q
how many primers do leading strands (pointing toward replication fork) need?
A
one
23
Q
How many primers do lagging strands (pointing back from the fork) need?
A
multiple for every single section you apply nucleotides to
24
Q
What happens during elongation for replication of DNA in bacteria?
A
Replication bubble grows as replication forks move in both directions.
25
Which polymerase adds DNA nucleotides to 3'OH of RNA primer for elongation?
DNA polymerase 3
26
What replaces RNA primers with DNA (corrects and methylates)?
DNA polymerase 1
27
What happens in termination?
The DNA replication is complete and replication stops
28
In termination, what is required at terminus to separate two circles?
topoisomerases
29
What is required for negative supercoiling?
gyrase
30
Which supercoiling is right-handed coiling of DNA (counterclockwise) to underwind?
negative
31
Which supercoiling is left-handed coiling of DNA (clockwise) to increase coiling for DNA packaging?
Positive
32
What do single-strand binding proteins do on ssDNA?
protect from nuclease destroying it
33
What does a DNA ligase do?
Joins okazaki fragments during DNA replication.
34
What does RNA primer do in bacteria?
provides short RNA strand with a free 3' OH group for DNA polymerase III
35
Gyrase is which coiling?
negative
36
an external force that causes dna mutations
mutagen
37
what are 2 mutagens?
carcinogen (chemical)
radiation (physical)
38
what is the cause of pyrimidine dimers?
covalent bonding of two adjacent pyrimidines on the same strand.
39
what test uses bacteria to test whether a given chemical can cause mutation in the DNA of the test organism?
AMES
40
what mutation is a single nucleotide that is changed to another?
point mutation (substitution)
41
What mutation is the removal of one or more nucleotides?
deletions
42
What mutation is the addition of one or more nucleotides?
insertion
43
What mutation is when a fragment is flipped in orientation?
inversion
44
How many strands of DNA are transcribed in bacteria?
1
45
What does the sense strand do in transcription for bacteria?
it should make the mRNA identical to original IT'S THE RNA sequence
46
What does the template strand do in transcription for bacteria?
It will make an opposite of the sense strand
47
If you have an mRNA strand of UACCGA what will the sense strand be and what will the template strand be?
Sense: ATACCGA
Template: TATGGCT
48
transcription requires 2 proteins. What are the called together and separate?
holoenzyme, sigma factor, RNA polymerase
49
What does the sigma factor do?
DNA binding protein that recognizes the sequence of 2 locations upstream of the gene (template -10 and -35)
50
What does the RNA polymerase do in bacteria transcription?
Binds to the sigma protein, separates DNA and builds RNA till it reaches the termination signal.
51
Where does the sigma factor detach from the RNA polymerase?
at the promotor
52
what number is the promoter in bacteria transcription?
-35 and -10
53
where are the codons found in bacteria?
mRNA
54
AUG always codes for?
methionine
55
How many amino acids will we have for this sequence? AACGCAUGCUUACUGAUUGACACG
4
56
what does the anticodon do?
it makes the opposite end attract a very specific amino acid
57
What is translation initiation?
Binding of mRNA to a ribosome
58
What prime does a Eukaryotic mRNA require?
5' cap and 3' poly A tail
59
What does a Prokayotic mRNA require?
shine dalgarno sequence (doesn't require 5'-3'
60
what does shine dalgarno do?
promotes the transcription of operons. ribosomal binding site
61
rRNA is a ______ because it helps bind
enzyme
62
what happens if there is an AUG in the middle of a prokaryotic mRNA and doesn't have a shine dalgarno?
it just brings in a methionine, it doesn't start again.
63
translation elongation has 3 sites. What are they and what do they do?
P site: polypeptide building site
A site: Arrival site
E site: exit site
64
What mutation is a change in DNA sequence but no change in the amino acid sequence; no affect of protein function?
silent mutation
65
what mutation is when a change in DNA sequence changes the amino acid sequence; may or may not affect protein function (results in an amino acid substitution)
Missense mutation
66
What mutation causes a truncated protein with
loss of function
Nonsense mutation
67
Which sequence has a 5-3 and which has a 3-5?
sense strand, template
68
What mutation shifts all amino acids downstream
of mutation; makes a new protein, may or may not be functional
frameshift mutation
69
If the protein function is affected is it silent or missense mutation?
Missense mutation
70
What is the difference between prokaryote and eukaryote translation?
E:Met, transcription and translation separately 80S
P:Fmet, shine dalgarno, transcription and translation simultaneously 70S, no mrna processing, operons, occurs in cytoplasm
71
what is transcriptional control for gene expression in bacteria?
DNA-RNA, most efficient, slowest regulation,
72
what is translational control for gene expression in bacteria?
RNA-Protein, less efficient than transcriptional
73
what is post-translational control for gene expression in bacteria?
protein-modifications, least efficient, fast (slight modification turns on/off)
74
what does induction do?
Turns gene on
75
what does repression do in negative control?
turns genes off
76
what does a repressor protein do?
it inhibits gene expression
77
what does negative control use?
uses a repressor protein
78
What does positive control use?
activating protein
79
if you want to activate a gene in positive control what does it need?
induction by binding of activator protein
80
If you want to deactivate a gene in positive control, what do you do?
Repression by removing activating protein
81
What is a lac operon and what does it do?
encodes genes to break down lactose
82
what does lacZ do?
Beta galactosidase, breaks down lactose into glucose and galactose
83
What does lacY do?
Lactose permease, allows lactose into cell (like lacI which is a repressor protein
84
if lactose is absent what happens with the lac operon?
repressed
85
what does a repressor bind to?
operator
86
If lactose and glucose are present what happens to the lac repressor?
It's removed, but there is LOW gene expression
87
What happens when lactose is present but glucose is absent?
CRP activator protein which is activated by CAMP, binds to ABS; high gene expression
88
what are critical objects for microbial control?
Anything injected into the body (scalpels, needles, etc)
89
What are semi-critical objects for microbial control?
Objects that enter the body but don't come in contact with the blood (endoscope, endotracheal tube)
90
what are non-critical objects for microbial control
only exposed to surface of body (bedding, grooming)
91
What is sterilization?
removes all living or latent cells, spores, and viruses. Necessary for critical objects.
92
What is disinfection?
Killing or removing microbes from inanimate objects; necessary for semi-critical objects
93
What is an antiseptic?
kills or removes microbes from living surface. (won't kill everything because it goes on skin)
94
What is sanitation?
Similar to disinfection but requires standards by governing bodies
95
what is BSL-4
microbes are dangerous and exotic, high risk aerosol-transmitted infections that are usually fatal (few labs)
96
What is BSL-3
Microbes are indigenous or exotic and cause serious potentially lethal diseases through respiratory transmission
97
What is BSL-2?
Microbes are typically indigenous and are associated with diseases of varying severity. They pose moderate risk
98
What is BSL-1
microbes are not known to cause disease in healthy hosts, minimal risk
99
-cidal means?
some control methods kill organisms
100
-static means?
some control methods stop organisms growth
101
what is the D-value
fixed percentage of microbes that die within a given time frame; measures amount of time it takes for 90% of the microbe population to die
102
What is the microbial death curve?
Evaluation of effectiveness of cidal agents
103
How do you control microbes (what methods to kill or slow down)?
Heat, radiation, drying, cold, filtration
104
what is moist heat?
bactericidal
105
what is dry heat?
bactericidal
106
what is pasteurization?
low heat
107
what is radiation?
bactericidal
108
What is drying?
bacteriostatic
109
What is cold?
bacteriostatic
110
What is the filter number that eliminates all pathogens?
.2um, .3 for HEPA air filters
111
what are surfactants?
soaps, lift and remove microbes, not kill
112
What are phenolics?
Phenol-first disinfectant in 1867 by joseph lister
113
What are halogens?
iodine (antiseptic) and chlorine (disinfectant)
114
What are alcohols?
ethyl and isopropal (antiseptic or disinfectant)
115
Why do antiseptics only work on surfaces?
There is no target so it just destroys everything. If you were to put it in your body, it would kill cells.
116
What do chemotherapeutic agents do?
Used to eliminate pathogens from the human body
117
what are examples of chemotherapeutic agents?
Antibiotics, antivirals, antifungals, anti-parasites
118
A chemical produced by one organism that can kill or inhibit the growth of another bacterial organism
antibiotic
119
What are natural antibiotics produced by?
molds and some bacterial species
120
what are semisynthetic antibiotics produced by?
modifying natural antibiotics to increase effectiveness
121
antibiotics are selectively toxic, what does that mean?
specific against bacteria and not host
122
who discovered penicillin and what was he studying and when?
alexander fleming, 1929 s aureus
123
who developed large-scale production of penicillin in 1942?
howard florey and ernest chain
124
who discovered penicillin's structure?
dorothy hodgkin
125
why slow the growth of bacteria instead of kill?
because they can release dangerous toxins when killed
126
What does bacteriostatic mean?
inhibits growthwh
127
at does bactericidal mean?
kills bacteria
128
bacteriostatic wont work for who?
immunocompromised
129
why would you prefer broad spectrum antibiotic?
if you don't know what the bacteria is and so you don't create resistance to narrow spectrum
130
Why would you prefer narrow spectrum antibiotic
so you can target a specific bacteria without killing normal flora
131
what is the minimal inhibitory concentration
the amount of drug that's going to inhibit the bacteria
132
what is the chemotherapeutic index?
ratio of the toxic does to the effective dose (TD:ED)
133
what is the effective dose?
if 50% of the population is treated and it works at a certain dose
134
what is the toxic dose?
when 50% of population experience harmful side effects.
135
what is the equation for chemotherapeutic index?
TD50/ED50
136
The higher the chemotherapeutic index the _____ the drug
safer
137
What is minimal bactericidal concentration?
lowest concentration of drug required to kill pathogen
138
how do you determine the MIC?
based on the vial with no turbidity (cloudiness)
139
How do you determine MBC?
If you plate and the plate that has no growth.
140
what is the zone of inhibition?
it determines the susceptibility of the organism
141
what is an E-Test?
it is a strip with antibiotic that is diluted as it goes down.
142
What is the basic structural unit of a DNA?
There is a nucleotide that consists of a deoxyribose sugar, phosphate group , and a nitrogenous base
143
What are the nitrogenous bases of bacterial DNA and how do they pair?
adenine with thymine and cytosine with guanine
144
What bases are pyrimidines?
Cytosine and thymine
145
What bases are purines?
Adenine and guanine
146
What is the strand directionality in bacterial dna?
antiparallel, one runs 5-3 and the other runs 3-5
147
What is the backbone structure of bacterial DNA?
alternating deoxyribose sugars and phosphate groups, connected by phosphodiester bonds. The bases project inward, forming hydrogen bonds with their compliments
148
What are the two most common targets for antibiotics?
cell wall (peptidoglycan), ribosomes
149
what are uncommon targets of antibiotics?
Nucleic acid synthesis
metabolic pathways (folic acid synthesis)
plasma membrane
150
What are inhibitors of cell wall synthesis?
Beta-lactams
Glycopeptides
bacitracin
151
What does beta lactams do?
inhibit enzyme activity of cell wall synthesis
152
What are examples of beta lactams?
penicillin, cephalosporins, carbapenems, amoxicillin
153
What do glycopeptides do?
prevent cell wall cross-linking
154
what is an example of glycopeptides?
vancomycin
155
What does bacitracin do?
inhibits enzyme activity of cell wall synthesis
156
what does beta lactams target?
transpeptidase
157
what does penicillin target?
gram + bacteria
158
what targets gram negative bacteria?
monobactams
159
what is an example of a polypeptide
bacitracin
160
what does polypeptides do?
inhibit cell wall synthesis by inhibiting phosphorylase enzymes
161
What do macrolides do?
binds to 50S ribosome unit to prevent peptide bond formation and stops protein synthesis
162
What is an example of a macrolide?
Erythromycin, azithromycin
163
What do aminoglycosides do?
Bind to the 30S ribosomal unit to impair proofreading which results in production of faulty proteins
164
What is an example of aminoglycosides?
streptomycin, gentamicin
165
What does tetracyclines do?
Bind to 30S ribosome subunit to block binding of tRNAs, inhibiting protein synthesis
166
what is an example of a tetracycline
doxycycline
167
What do quinolones do?
inhibits DNA gyrase
168
what are inhibitors of nucleic acid sythesis?
quinolones and metronidazole
169
what does metronidazole do?
nicks DNA at random
170
What antibiotics target plasma membrane?
Polymyxins, platensimycin
171
What does platensimycin do?
Inhibits fatty acid production needed for cell membrane
172
What do antivirals target in replication cycle?
attachment/uncoating, genome release, viral release, replication
173
what does horizontal gene transfer help bacteria with?
resistance because of plasmids
174
What methods does a pathogen use to develop resistance?
modifies drug cellular target, mutates, modifies drug structure or degrades it through horizontal gene transfer, alters concentration of drug, prevents drug from entering by blocking penetration, pumps drug out of cell
175
What antibiotic has most problems with resistance?
beta lactam
176
what do drugs to inhibit/avoid resistance do?
bind to prevent degradation like clavulanic acid with binds to beta lactam to prevent penicillin degradation
177
What is phage therapy?
Virus invades specific bacteria using lytic cycle to kill
178
what is the study of the molecular and cellular interaction between a host and introduced foreign molecules?
immunology
179
What is the first line of defense?
innate immunity
180
What is the second line of defense?
Adaptive immunity
181
What is innate immunity?
you are born with it (skin)
182
What is adaptive immunity?
you must be exposed before it can work (cell mediated immunity)
183
what does immunity mean?
ability to resist FUTURE infections caused by previously encountered pathogens
184
Which immunity is non specific?
innate
185
Which immunity depends on exposure?
adaptive
186
Which immunity is specific?
adaptive immunity
187
Which immunity prevents or slows the entry of foreign pathogens?
innate immunity
188
Which immunity is delayed but effective response?
adaptive immunity
189
Which immunity has two divisions, humoral and cell mediated? (b cell and t cells)
Adaptive
190
Which immunity attacks pathogens that breech barrieres?
innate immunity
191
Which immunity has a rapid response?
innate immunity
192
Which immunity has a memory of previous invaders?
adaptive immunity
193
Which immunity has no memory of previous invaders?
innate immunity
194
Which immunity is present at birth?
innate immunity
195
Which immunity is skin, mucosal membranes, washings, and secretions?
Non-cellular innate immunity
196
Which immunity has phagocytosis and immunological surveillance?
Cellular attacks (second innate defense) innate immunity
197
What are examples of non-cellular innate immunity?
Physical barriers (skin, mucosal membrane), fever, circulating proteins, cytokines, inflammation
198
What are examples of cellular attacks innate immunity?
Phagocytosis, immunological surveillance (NK cells)
199
what are physical barriers for innate immunity?
skin, mucous membranes, epithelial cells
200
What are secretions and mechanical barriers of innate immunity?
sweat, tears, saliva, vomit, diarrhea, urine, sneezing, mucociliary escalator
201
What are examples of chemical defenses of innate immunity?
Sebum, lysozyme (tears, mucus), HCL in stomach, antimicrobial peptides
202
what is a fever caused by?
pyrogens
203
What is the complement system?
over 20 proteins that circulate in the blood and interstitial fluid that protect against infections
204
what are the complement proteins activated by?
binding to microbes or antibodies
205
What does binding of complement proteins lead to?
Phagocytosis by opsonization, lysis of target cell, local inflammation
206
what are the two main pathways of activation in the complement system?
classical, alternative
207
What does the classical pathway in the complement system require?
adaptive system (antibody)
208
What does the alternative pathway in the complement system require?
direct activation by bacterial cell
209
The process by which either antibodies or complement proteins bind to the surface of an antigen to identify
opsonization
210
what do a and b in complement proteins do?
a-inflame, b-opsin
211
What is the MAC?
Membrane attack complex, drills holes into cells to cause lysis
212
what does c5b, c6, c7, c8, c9 do in the complement system?
MAC
213
what does c1 do?
phagocytosis
214
what does c3 convertase do
hydrolyzes and creates more c3
215
What are cytokines?
proteins that are being secreted to manage the immune system (stimulate, inhibit)
216
What are chemokines?
cytokines that induce chemotaxis (attract)
217
What are interferons?
Cytokines that interfere with viral replication. They send out signals to neighbors telling them to make viral resistance when they are infected, and signal macrophages
218
What are interleukins?
Cytokines that promote T and B cell development
219
What are Tumor necrosis factors (TNF)?
Cytokines that promote apoptosis
220
Interferons also induce expression of ________
enzymes to cleave to viral RNA or to inhibit translation
221
The formation of blood
hemotopoiesis
222
What are blood stem cells called?
hemocytoblasts
223
What do myeloid blood cells include?
leukocytes (red blood, eosinophils, basophils, neutrophils, monocytes, mast cells, macrophages, dendritic)
224
What do lymphoid blood cells include?
lymphocytes (NK, T, B cell)
225
What are granulocytes?
Basophil, neutrophil, Eosinophil
226
What are agranulocytes
Macrophage, dendritic cells
227
What are lymphocytes?
T, B cells and NK
228
What do neutrophils do?
Phagocytosis, antibacterial, pus
229
What are elevated during a bacterial infection?
Neutrophils
230
What do Eosinophils do?
Kill parasites, involved in allergic responses, have lysozymes
231
What do Basophils do?
Release histamine, signal for allergic responses
232
What do mast cells do?
contain histamine and heparin, inflammation
233
Do mast cells circulate?
no they stay in the tissues
234
What do monocytes do?
Phagocytes, differentiate into macrophages or dendritic cells
235
What do macrophages do?
Destroys pathogens and release cytokines for inflammation
236
What do dendritic cells do?
In skin and present cells with antigens
237
what are pamps?
They are the molecular arrangements displayed by most pathogens (identifying factors so we can identify a pathogen with receptors)
238
What are PRRs
WBCs display receptors that bind to and recognize pamps (receptors that identify pathogens)
239
How does an NK cell work?
it is on surveillance, looking for abnormal cells, when its activating molecule is activated, it secretes toxins (perforin) to break it down.
240
What two toxins does NK cells release and what do they do??
perforin and cytotoxic enzymes, punch holes in bacteria
241
What kills cells coated with ADCC (antibody dependent cell mediated cytotoxicity)
NK cells
242
What is a normal count for wbc?
4500-11,000
243
If you have a bacterial infection, which WBC increases?
neutrophils, producing immature forms (band cells)
244
What do neutrophils do in a viral infection?
decrease
245
Lymphocytes increase in which infection?
viral
246
What does acute inflammation provide us?
Destroys offending agents, walls off and localizes infection, turns on immune system (phagocytes), repairs tissue damage
247
What is the classical inflammation sequence vascular phase?
mast cells and basophils release histamines to vasodilate and increase capillary permeability (leaking tissue, brings WBCs, platelets, proteins)
248
What is the classical inflammation sequence cellular phase?
Leukocytes arrive, attracted because of positive chemotaxis
249
What is the classical inflammation sequence systemic phase?
Body's response to inflammation
fevers, soreness, increased WBCs, elevated inflammatory markers caused by chemical mediators of inflammation (cytokines, prostaglandins, leukotrines)
250
What are 5 signs of inflammation?
heat, redness, swelling, pain, loss of function
251
what does fluid do in the vascular phase?
dilutes toxins/antigen
252
What do you call the fluid that leaks out of the blood vessels that cause local swelling?
Transudative or exudative fluid
253
What is extravasation?
leakage of blood contents into surrounding tissues (not red blood cells)
254
What is diapedesis?
Ability of WBCs to squeeze through blood capillary walls to enter tissue
255
What is a rolling neutrophil?
it binds and releases to a receptor to slow until it slows enough to stop and adhere to an integrin
256
What is margination?
neutrophils lines up against endothelium binding to selectins
257
What is adhesion?
Neutrophil cell integrins bind to endothelial adhesion molecules
258
What is emigration?
Cells move through the vessel wall to the affected area and squeeze between cell walls (diapedesis)
259
What are chemical mediators of inflammation?
Prostaglandins, cytokines, leukotrines
260
What causes loss of function?
pain or swelling
261
What is chronic inflammation?
Inflammation the persists and is not resolved
262
What cells does chronic inflammation involve?
Lymphocytes and macrophages
263
What does chronic inflammation lead to?
host tissue damage
264
What are 3 examples of chronic inflammation?
Hepatitis, granulomas, abscesses
265
