Exam #3 Study Guide Flashcards
1
Q
central dogma
A
overall flow of genetic information
2
Q
genetics
A
study of genes, how they carry information, how information is expressed and how they are replicated
3
Q
gemine
A
all the genetic information
4
Q
chromosome
A
structures containing DNA that physically carry hereditary information, contains genes
5
Q
gene
A
segment of DNA that encode functional products
6
Q
genetic code
A
set of rules that determines how a nucleotide sequence is converted to an amino acid sequence in a protein
7
Q
geneotype
A
genetic makeup of an organism and represents potential expression
8
Q
pheotype
A
expression of actual genes, represents actual expression
9
Q
genomics
A
the sequencing and molecular characterization of genomes
10
Q
DNA gyrase
A
relaxes supercoiling ahead of the replication fork
11
Q
DNA ligase
A
makes covalent bonds to join new strands, Okazaki fragments and new segments in excision repair
12
Q
DNA polymerase
A
synthesize DNA, proofreading and facilitating DNA repair
13
Q
topoisomerase
A
relaxes supercoiling ahead of the replication fork and separates DNA circles at the end of DNA replication
14
Q
helicase
A
separates stands
15
Q
replication fork
A
The point at which the two strands of DNA are separated to allow replication of each strand.
16
Q
top stand is the
A
3’-5’
17
Q
the lagging stand is
A
5’-3’
18
Q
top strand is the
A
leading strand
19
Q
primase places
A
RNA primers
20
Q
transcription
A
transcribe the DNA in to a message
21
Q
transcription occurs in the _________ in eukaryotic cells
A
nucelus
22
Q
RNA polymerase transcription role
A
copies RNA from a DNA template
23
Q
transcription begins when RNA polymerase binds to the
A
promoter sequence
24
Q
in transcription only
A
one strand is transcribed
25
3 stages of transcription
initiation, elongation, termination
26
initation
RNA polymerase binds to the DNA and recognizes a site called _________ at the end of 3' end of the template strand of the target gene. When RNA polymerase finds a promoter it breaks ___________ ______ holding the DNA strands together at the site of the promoter and __________ begins
promoter, hydrogen bond, transcription
27
RNA polymerase does not bind to all promoters with equal __________
affinity
28
the difference in promoter strength is one way that cells can control _______ __________. The more strongly RNA polymerase binds to a particular promoter the more likely the gene is to be ___________
gene expression, transcribed
29
in elongation one strand of the DNA serves as the _______ ________ and the RNA is transcribed from this
template strand
30
elongation continues until it reaches the
Terminator
31
at the termination site the
RNA polymerase and the newly synthesized RNA transcript are released
32
termination can occur in 2 mechanisms
self termination and enzyme dependent termination
33
self termination
RNA sequence transcribed at the terminator causes the RNA to hydrogen bond with itself forming a stem loop structure which essentially pulls the RNA polymerase off
34
enzyme dependent termination
termination protein binds to the terminator and pushes RNA polymerase off the DNA
35
codons
groups of 3 mRNA nucleotides the code for a particular amino aicd
36
degeneracy
each amino acid is coded by several codons
37
START
AUG
38
STOP
UAA, UAG, UGA
39
what components are needed for translation
ribosome, tRNA, mRNA
40
translation step 1
on the assembled ribosome a tRNA carrying the first amino acid isa pried with the ______ ______ on the mRNA. The place where this first tRNA sits is called the _______ site
start codon, P site
41
translation step 2
the second codon of the mRNA pairs with a tRNA carrying the second amino acid at the ___ site. The first amino acid joins to the second by a _______________ bond. this attaches the polypeptide to the tRNA in the __ site
A site, polypeptide, P site
42
translation step 3
the ribosome moves along the mRNA until the second tRNA is in the __ site. The next codon to be translated is brought into the ___ site. The first codon now occupies the ___ site
P, A, E
43
translation step 4
the second amino acid joins to the third by another ________ _______ and the first tRNA is _______ from the E site
peptide bond, released
44
translation step 5
when the ribosome reaches a stop codon
the polypeptide is released
45
prokaryotes transcription location
cytoplasm
46
eukaryotes transcription location
nucelus
47
prokaryotes: can translation begin BEFORE transcription is complete
YES
48
eukaryotes: can translation begin BEFORE transcription is complete
NO
49
prokaryote translation location
cytoplasm
50
eukaryote translation location
cytoplasm
51
3 things that are unique to just eukaryotic cells
exons, introns, snRNPs
52
exons
regions of DNA that code for proteins
53
introns
regions of DNA that do NOT code for proteins
54
snRNPs (small nuclear ribonucleoprotein)
remove introns and splice exons together
55
mutation
permanent change in the base sequence of DNA
56
mutagens
agents that cause mutations
57
Ames test
exposes mutant bacteria to mutagenic substances to measure the rate of reversal of the mutagen
indicates the degree to which substance is mutagenic
58
2 types of repairs to fix mutagens
photolyases
nucleotide excision repair
59
photolyses use what to break apart what
use visible light to break apart thymine dimers
60
nucleotide excision reapir
enzymes cut out incorrect bases and fill in correct
61
nucleotide excision repair are also called
dark reactions
but can occur with or with out lighr
62
2 ways to identify mutagens
positive (direct) selection
negative (indirect) selection
63
positive (direct) selection
detects mutant cells because they grow/appear different than unmuated cells
64
negative (indirect) selection
detects mutant cells that cannot grow or preform a certain function
65
auxotroph
mutant that has a nutritional requirement absent in the parent
66
how to identify a auxotroph
replica plating
67
constitutive genes
expressed at a fixed rate (not regulated but constantly produced at this rate)
68
operons
segment of DNA where RNA polymerase imitates transcription of structural genes
69
operon consists of
promoter and operator
70
promoter
segment of DNA where RNA polymerase imitates transcription of structural genes
71
operator
segment of DNA that controls transcription of structural genes
72
all of the structural genes of an operon are transcribed into a single _____ which is then translated into this entire set of _________
mRNA, proteins
73
pre transcriptional contro;
epigenetic control, repression, induction
74
epigenetic control, how do you turn nucleotides off
methylating them
75
methylated genes can be or cannot be passed to offspring
can
76
is epigenetic control permeant or not
not permanent
77
repression
inhibits gene expression and decrease enzyme synthesis
78
repressor is mediated by
repressors
79
repressors are
proteins that block transcription
80
the default position for repression is
on
81
repressible operons
are always transcribed unless deactivates by a repressor
82
induction
turns genes on
83
induction is initiated by an
inducer
84
default position of induction is
off
85
inducible operons
not transcribed unless they are activated by an inducer
86
example of inducible operon
lac operon of E. coli
87
3 parts of lac operon
promoter, operator, 3 structural genes
88
the 3 structural genes of lac operon encode for proteins involved in
catabolism of lactose
89
when lactose is available to the cell the operon is _______________ to produce the proteins of lactose catbolism
induced/stimulated
90
e.coli has a regulator gene near lac operon and this gene is constantly transcribed and translated to produce
repressor protein
91
the repressor protein binds to the operator DNA at lac operon physically preventing
RNA polymerase from moving beyond the promotor
92
when a repressor protein is bound the genes for lactose catabolism can to cannot be transcribed
cannot
93
when lactose is present in the cell some of it is converted to
allolactose
94
allolactose binds to the repressor proteins and
inactivates them which prevents them from binding to the operator
95
once the repressor proteins are inactivates the structural genes are now transcribed resulting in the production
of the enzyme needed to catabolize lactose
96
in lac operon the inducer is ____________ because it stimulates transcription of lac operon
alloactose
97
an example of a repressible operon is
trp operon in e.coli
98
3 parts of tap operon
promoter, operon and 5 structural genes
99
5 structural genes encode for proteins involved in the biosynthesis fo
tryptophan
100
when excess tryptophan is available to the cell the operon is ___________ ending the production of the proteins of tryptophan biosynthesis
repressed
101
e coli contains a regulatory gene near the trp operon and this gene constantly transcribed and translated to produce
repressor proteins
102
repressor proteins of trp operon are inactive unless
excess tryptophan is avaibale
103
the repressor proteins of trp operon can be activated by
tryptophan
104
once the repressor protein is activated by tryptophan it can bind to the trp operon preventing
RNA polymerase from moving beyond the promotor
105
when a repressor protein is bound to trp operon the genes for tryptophan biosynthesis cannot be transcribed into
mRNA
106
post transcriptional control
riboswitch
microRNAs
107
riboswitch
part of an mRNA molecule that binds to a substrate and changes the mRNA structure
translation is initiated or stopped
108
mircoRNAs
base pair with mRNA to make it double stranded
double stranded RNA is enzymatically destroyed preventing production of a protein
109
positive regulation
catabolite repressoin inhibits cells from using carbon sources other than glucose
110
cAMP
builds up in the cell when glucose is not available
111
cAMP binds to
CAP
112
CAP binds to
lac promotor
113
lac promotor
imitates transcription allowing the cell to use lactose
114
genetic recombination
exchange of genes between two DNA moleules; creates genetic diversity
115
crossing over
two chromosomes break and rejoin resulting in there insertion of foregin DNA into the chromosome
116
vertical gene transfer
transfer of genes from an organism to its offspring
117
horizontal gene transfer
transfer of genes between cells of the same generation
118
2 types of mobile genetic elements
plasmids and transposons
119
mobile genetic elements
move from one chromosome to another or from one cell to another
120
are plasmids self replicating or not
self repliating
121
plasmids are what shape
circular
122
plasmids often code for proteins that enhance the
pathogenicity
123
3 types of plamsids
conjugative plasmid, dissimilation plasmids, resistance factors
124
conjugative plasmids
carries genes for sex villi and transfer of the plasmid
125
dissimilation plasmid
encode enzymes for catabolism of unusual compunds
126
resistance factors
encode antibiotic resistance
127
two groups of resistance factor genes
RTF, and r determinant
128
transposons
segments of DNA that can move from one region of DNA to another
129
transposons contain
insertion sequences
130
insertion sequences code for
transposes that cuts and reseals DNA
131
2 types of transposons
simple and complex
132
simple transposons
only contain the essential elements needed for trans positioning
133
simple transposons are compose of
transposes gene flanked by an inverted repeat
134
simple transposons are complete units capable of effecting their own movement from
one location to another
135
inverted repeat sequin is a region of DNA in which the sequence of nucleotides is
identical to an inverted sequence in the complementary strand
136
the transposase enzyme recognizes this inverted repeat in a target site and
inserts the transposon or a copy into the DNA moleules at such target site
137
the transposase gene codes for the enzyme that
facilitates the movement of the transposon
138
transposase cuts the DNA so the transposon can
leave its original position
139
transposase also cuts the DNA in new positions where the
transposon inserts itself and creates the covalent bond between the transposon and its new host DNA
140
simple transposons move through 2 types of mechanisms
cut and paste and replicative
141
cut and paste
the entire transposon moves to another location
142
replicative
transposon is copied to a new location
143
complex transposons
carry other genes and transposase gene
144
complex transposons consist of
two simple transposons with another sequence of DNA between them
145
in a complex transposon the other gene is often something that gives
select advantage to the organism containing the transposon
146
ends of complex transposons are
insertion sequences
147
the insertion sequences are capable of
moving/coping themselves independent of the rest of the complex transposons
148
the element in the middle of the complex transposon can or cannot move on its own
cannot
149
3 types of horizontal gene transfer
transformation, conjugation, transduction
150
transformation
genes transferred from one bacterium to another as 'naked' DNA
151
transformation
some bacteria are capable of taking up fragments of DNA from
their surroundings and integrating the fragments into their own chromosome by recombiniation
152
competent
cells capable of taking up DNA from their environment
153
species that is naturally compenent
streptococcus pneumoniae
154
species that can be MADE compenent
e. coli
155
conjucation
plasmids transferred from one bacterium to another
156
conjugation requires cell to cell contact via
sex pilli
157
2 types of conjucation
f factor and Hfr
158
F factor F+ cells
cells containing an F factor and serve as DNA donors during conjucation
159
F factor F- cells
cells lacking F factor and serve as DNA recipients during conjucation
160
conjucation F factor
Conjucation pills extends from an _____ cell to an ____ cell and pulls the cells together, the cells come together and stabiliz. Transfer of DNA begins. A _________ stranded copy of the F factor is transferred from F+ to F-. each cell synthesizes a complementary strand of plasmid resulting in a __________ copy of the plasmid in each cell.
F+, F-, single, complete
161
Hfr conjugation contains the F factor on the
chromosome
162
Hfr conjucation
Occasionally an F factor integrates into the E.coli __________ converting the F+ cell to an ________ cell. Hfr form conjucation pili and cells come together and stabilize. Transfer of DNA. DNA transfer begins in the _________ of the F factor within the HFr cells chromosome, the result is the F- cell does not receive a full copy of the F factor since the recipient cell does not revieice a full copy of the F factor it is still ___. However the DNA from the donor can recombine with recipient chromosome giving the recipient new chromosomal ________
chromosome, Hfr, middle, F-, genes
163
transduction
DNA is transferred from donor cell to recipient via bacteriophage
164
2 types of transduction
general and specialized
165
general transduction
random bacterial DNA is packaged inside a phage and transferred to a recipient cell
166
specialized transdcution
specific bacterial genes are packaged inside a phage and transferred to a recipient cell
167
mutations and recombination create
diverity
168
natural selection
acts on populations of organisms to ensure the survival of organisms within a particular environment
169
biotechnology
use of microorganisms, cells or cell components to make a product
170
example of products from biotechnology
foods, antibiotics, vitamins, enzymes
171
biotechnology selection
selecting for a naturally occurring microbe the produces a desired product
172
biotechnology mutation
mutagens cause mutations that might result in a microbe with desirable trait
173
biotechnology site directed mutagensis
a targeted and specific change in a gene
174
recombinant DNA (rDNA) technology
insertion or modification of genes to produce desired proteins
175
examples of rDNA
gene encoding for a protein for pest resistance
gene encoding segregative enzyme to clean up toxic waste
human growth hormone
amylase, cellulase and other enzymes prepare for clothing manufacture
176
vector
self replicating DNA molecule used to transport foregin DNA into a cell
177
vector can carry new DNA to
desired ell
178
a vector MUST
BE ABLE TO SELF REPLICATE
179
what can be used as a vector
plasmids and viruses
180
shuttle vectors
exist in several different species and can move cloned sequences among various organisms
181
clone
population of genetically identical cells arising from one cell; each carries the vector
182
restriction enzymes
cut specific sequences of DNA
183
restriction enzymes ____________ phosphodiester bonds between individual nucleotides at specific recognition sequences on both strands of DNA and they are able to ____ or ______ the DNA sequence the same way everytime
hydrolyze, cut, digest
184
restriction enzymes occur naturally in bacterial cells and are able to destroy
invading DNA
185
restriction enzymes create blunt ends or staggered cuts known as sticky ends. what one is better for cloning
sticky ends
186
polymerase chain reaction (PCR)
process of increasing samll quants of DNA for analysis
187
PCR is used diagnostic tests for
genetic diseases and detecting pathogens
188
3 steps of PCR
denaturation
priming
extension
189
denaturation
DNA is incubated at high temps which causes strands to separate by breaking the hydrogen bonds between each base pair
190
priming
DNA is incubated at a relatively low temp allowing primers to attach to the single stranded target DNA
191
extension
DNA is incubated at an intermediate temp at which the DNA polymerase rapidly replicates DNA
192
PCR occurs in what machine
thermocylcer
193
target DNA
piece of DNA being amplified in the PCR reaction
194
Reverse transcriptase PCR
uses mRNA as template and reverses the normal flow of genetic information utilizing the enzyme reverse transcriptase, mRNA is used to create cDNA
195
ways DNA can be incorporated into the cell
transformation, electroporation, protoplast fusion, gene gun, microinjection
196
transformation
cells take up DNA from the surrounding environment
197
electroporation
electrical current forms pores in plasma membrane
198
protoplast fusion
removing cell walls from 2 bacteria allows them to fuse
199
gene gun is used in
plant
200
microinjection
technique that uses a glass micropipette with a diameter much smaller than that of the cell and is able to puncture the plasma membrane so that DNA can be injected through it
201
genomic libraries are collection of
clones containing different DNA fragments
202
complementary DNA is made from mRNA by
reverse transcriptase
203
cDNA is used for obtaining eukaryotic genes because eukaryotic genes have
introns
204
synthetic DNA
builds genes using DNA synthesis machine
205
selecting a clone
blue white screening, colony hibridization
206
blue white screening uses a plasmid vector containing
amplicllin resistance gene and b-galactpsidease
207
blue white screening
bacteria is grown in media containing amplicllin and X gal only the bacteria that have picked up the plasmid will grow because they are now ampicillin reistance
208
white colonies
bacteria that have picked up the recombinant plasmid will not hydrolyze lactose
209
blue colones
bacteria with the intact lacZ gene will hydrolyze the x-gal
210
colony hybridization
common method of identifying cells that cary a specific gene
211
colony hybridization uses
DNA probes
212
DNA probes are
short segments of single stranded DNA complementary to the desired gene
213
gene produces are frequently the reason for
genetic modifcation
214
E. coli advantages
easily grown
genomics are known
215
E. coli disadvantages
produces endotoxins
216
saccharomyces cerevisaiae
easily grown and larger genome
express eukaryotic genes easily
likely to continuously secrete product
217
plant cells
express eukaryotic genes easily
easily grown
large scale
low cost
218
mammalian cells
express eukaryotic genes easily
can make products for medical use
harder to grow
219
2 ways to silence genes
siRNAs
RNAi
220
siRNA
bind to mRNA which is then destroyed by RNA induced silencing complex
221
RNAi
inserts DNA encoding siRNA into a plasmid and transferred into a cell`
222
viruses are obligatory intracellular parasites meaning
require living host cells to multiply
223
viruses contain
DNA/RNA
224
viruses have a _________ coat
protein
225
viruses have no
ribosomes and ATP-generating mechanisms
226
viruses are sensitive to
interferon
227
host range
spectrum of host cell a virus can infect
228
most viruses infect only specific types of cells in one
host
229
bacteriophages
viruses that infect bacteria
230
genus
-virus
231
family
-viridae
232
order
-ales
233
subspecies are designates by a
number
234
viral species
a group of viruses sharing the same genetic information and ecological niche (host)
235
viruses must be grown in
living cells
236
bacteriophages are grown in
bacteria
237
bacteriophages form
plaques
238
plaques are
clearings on lawn of bacteria on the surface of agar
239
each plaque corresponds to a single
virus
240
plaques can be expressed as
plaque forming units
241
growing animal viruses
in living animals
embryonate cells
cell cultures
242
embryonated eggs
virus injected into the eggs
viral growth is signaled by changes or death
243
what is the most convientiet way
cell cultures
244
cell cultures
tissues are treated with enzymes to separate cells
245
in cell cultures _______ cell lines are used
continuous
246
normal cells grow in __________ across the container
monolayer
247
transformed cells
do not grow in monolayer
248
viral identification
cytopathic effects
serological tests
nucleic acids
249
seroglical test example
western blotting
250
western blotting
reaction of the virus with antibodies
251
nucleic acids example
RFLPs
PCR
252
for a virus to multiply it must
invade host cell and take over hosts machinery
253
bacteriophage 2 cycles
lytic and lysogenic
254
lytic cycle causes
death of host
255
what bacteria go through lytic cycle
T-even
256
lytic cycle steps
attachment
phage attaches by the tail fibers to host cell
257
lytic cycle steps
penetration
phage lysozyme opens the cell wall; tail sheath contracts to force the tail core and DNA into cell
258
lytic cycle steps
biosynthesis
production of phage DNA and proteins
259
lytic cycle steps
maturation
assembly of phage particles
260
lytic cycle steps
release
phage lysozyme breaks cell wall
261
lysogenic cycle
phage DNA is incorporated in the host DNA
262
lytic cycle uses what transduction
general
263
lysogenic cycle uses what transduction
specialized
264
what cycle does bacteriophage lambda use
lysogenic
265
lysogeny
phage remains latent
266
during lysogenic cycle phage DNA incorporates into
host cell DNA
267
prophage
inserted phage DNA
268
during lysogenic cycle when the host cell replicates its chromosome
it also replicates prophage DNA
269
lysogenic cycle results in
phage conversion
270
phage conversion
host cell exhibits new properties
271
in temperate bacteriophages the phage DNA forms a ______ which can either replicate and be transcribed to produce phage components in the lytic cycle or proceed to __________ ______
circle, lysogenic cycle
272
multiplication of animal viruses steps
attachment, biosynthesis, maturation
273
attachment of animal viruses
viruses attach to the cell membrane
274
entry of animal viruses by
receptor mediated endocytosis or fusion
275
biosynthesis of animal virsues
production of nucleic acids and proteins
276
maturation of animal viruses
nucleic acid and capsid proteins assemble
277
animal viruses vary based on
nucleic acids, naked or enveloped
278
naked viruses
without an envelope
bind to surface of host cell and inject their DNA
279
membrane fusion
infect their host by binding to receptors on host cell
envelope of the virus merges with the host membrane and then capsid enters the cell, the capsid opens and released the viral genetic material into cytoplasm
280
phagocytosis
host cell envoploes the viral envelope and absorbs the virus and once it has entered the host the outer and inner part of the envelope merge together and the capsid is released into the cytoplasm
281
biosynthesis of DNA viruses, they replicate their DNA in ____________ of the host using ______ ____________
nucleus, viral enzymes
282
adenovirus strands
double
283
adenovirus envelope
no
284
adenovirus diease
respiratory infection
285
poxviridae strands
double
286
poxviridae envelope
yes
287
poxviridae diease
skin lesions, smallpox
288
herpesvirdae strands
double
289
herpesvirdae envelope
yes
290
herpesvirdae diease
cold sores, chickenpox, mononucleosis, kaposis sarcoma
291
papoviridae strands
double
292
papoviridae enveloped
no
293
papoviridae diease
warts and cancer
294
hepadenaviridae strands
double
295
hepadenaviridae enveloped
yes
296
hepadenaviridae diease
Hep B
297
biosynthesis of RNA virsues
virus multiples in the host cells cytoplasm using RNA dependent RNA polymerase
298
biosynthesis of RNA virsues
ssRNA +(sense) strand
viral RNA serves as mRNA for protein
299
biosynthesis of RNA virsues
ssRNA- (antisense) strand
viral RNA is transcribed to a + strand to serve as mRNA for protein synthesis
300
picornaviridae strand
single
301
picornaviridae envolpoed
non
302
picornaviridae disease
enterovirus: poliovirus and coxsackievirus
rhinovirus: common cold
303
togaviridae strand
single
304
togaviridae enveloped
yes
305
togaviridae disease
alphavirus
rubivirus: rubella
306
rhabdovirdae strand
single
307
rhabdovirdae diease
lyssgavirus: rabies
308
reoviridae strand
double
309
reoviridae envoloped
no
310
reoviridae diease
reovirus, rotavirus
311
biosynthesis of RNA to produce DNA
use reverse transcriptase to produce DNA from viral genome
312
oncogenesis
transform normal cells into cancerous cells
313
oncogenic virus
become integrated into host cells DNA and induce tumors
314
transformed cell
harbors a tumor specific transplantation antigen on surface and a T antigen in the nucelus
315
why would viral cancer go without detection
most of the particles of certain viruses may infect cells without inducing cancer
may develop after long viral infection
cancers caused by viruses are not contagious
316
2 types of viral cancers
sarcoma and adenocarcinoma
317
sarcoma
cancer of connective tissue
318
adenocarcinoma
cancer of glandular epithelial tissue
319
DNA oncogenic viruses non cancer
adenovirus, herpesvirdae, poxvirdiae
320
herpesviridae
epstein barr
321
DNA oncogenic viruses cancer
papovaviridae, hepadnaviridae
322
papovaviridae leads to
cervical and anal cancer
323
hepadnaviridae leads to
hep b which leads to liver cancer
324
RNA oncogenic viruses
retroviridae
325
retroviridae
viral RNA is transcribed to DNA (using reverse transcriptase) which can integrate into host DNA
326
retroviridae can lead to HTLV1 and 2 and lead to adult T cell
leukemia and lymphoma
327
provirus
viral DNA that is integrated into the host cells DNA
328
oncolytic viruses
1900-1920, able to selectively infect and kill tumor cells or induce an immune response genetically modified to removed virulence genes and add CSF genes that promote WBS
329
oncolytic viruses can treat
melenoma
330
latent virus
remains asymptomatic in host cell for long periods
331
latent virus may reactivate due to change in
immunity
332
persistent virus
occurs gradually over long periods of time
333
examples of latent
cold sores, leukemia, shingles
334
examples of persistent
cervical and liver cancer, HIV/AIDS
335
plant viruses enter how
through wounds caused by insects
336
plant viruses normally are protected from disease by
cell wall
337
viroids
short pieces of naked DNA
338
virusoids
viriods enclosed in protein coat
339
prions are
proteinaceous infectious particles
340
prions are inherited via
ingestion, transplant, surgical instruments
341
example of transmissible spongiform encephalopathies
mad cow diease
sheep scrapie
creutzfeldt-jakob diease
GSS diease
fatal familial insomnia
342
PrP c
normal cellular prion protein on cell surface
343
PrP sc
scrapie protein, accumulates in brain cell forming plaques
344
normally PcP folds into a functional form with several
a helices
345
prion protein is capable of forming
B pleated sheets
346
infectious prions convert normal prions into more infectious ones by folding into
beta pleated sheet
347
infectious prions group into multimers which are very stable and resistance to
protease
