Test Block 3 Flashcards
1
Q
what kind of chromatin is actively dividing
A
euchromatin
2
Q
what does PCNA do
A
help to keep the polymerase bound
3
Q
proof reading ability of DNA is duect to a _________
A
3’ to 5’ exonuclease activity
4
Q
endonuclease occurs at the ________. exoonuclease occurs at the ______
A
middle; end
5
Q
Explain the steps of BER
A
- DNA cleaved by DNA MYH glycosylase
- recognized by AP endonuclease
- PARP binds
- Pol fills and ligase seals
6
Q
Explain steps of MMR
A
- MSH proteins detect mismatch
- MLH proteins recruit exonuclease
- pol fills, ligase seals
7
Q
lynch syndrome is associated with which repair mechanism
A
MMR
8
Q
lack of MLH1 leads to degradations of ____, lack of MSH2 leads to loss of ____
A
PMS2;MSH6 (MMR)
9
Q
how are thymine dimers repaired
A
NER
10
Q
explain steps of NHEJ
A
- ku70 and ku80 bind to broken ends
- nuclease artemis is recruited
- pol fills, ligase seals
11
Q
which repair mechanism uses sister chromatid as a template for repair?
A
homologous recombination repair (BRCA1, BRCA2, PALB). Loss of heterozygosity
12
Q
what is the order of repair mechanisms by length
A
BER, MMR, NER, HRR, NHEJ
13
Q
removes a postitive charge from lysine, making DNA easier to unwind and become transcriptionally active
A
HAT
14
Q
how does methyl groups encourage the packaging of DNA
A
by physically blocking the binding of transcription factors
15
Q
where does methylation of DNA occur
A
the 5’ carbon on cysteine
16
Q
antibodies contain _____ light and _____ heavy chains
A
two; two
17
Q
DNA elements that act at a distance to repress transcription
A
silencers
18
Q
how do steroid receptors work
A
HSP bind receptors in cytosol
ligand (cortisol) displaces HSP
GR dimerizes and enters nucleus
19
Q
what are the stop codons
A
UGA, UAA, UAG
20
Q
what is the start codon
A
AUG
21
Q
what does eIF3 do
A
prevents premature binding of ribosomal subunit
22
Q
what does EF1 do
A
Blocks the A site
23
Q
what does EF2 do
A
attach to charged tRNA
24
Q
How is EF2 regulated
A
when phosphorylated, it is inactive
25
How is EIF4 regulated
insulin binds, phosphorylates to activatew EIF4
26
what blocks the binding of aminoacyl tRNA by blocking the A site
tetracyclins
27
what binds to the 30s subunit to prevent intitation
aminoglyside (streptomycin)
28
what does erythromycin do
blocks 50s subunit
29
what inhibits peptides transferase
lincomycin and lindamycin
30
what activates EEF2
Diptheria Toxin
31
what antibiotics wrecks your teeth
tetracyclin and deoxycyclin
32
what enzyme catalyzes peptide bond formation
peptidyl transferase
33
how does tetracyclin prevent bacterial translation
blocks the A site
34
what was given to Dr. Rees son
clindamycin
35
to enter G1 cells must have
high concentration of growth factors
sense adhesion
have sufficient nutrients
36
what does increased cyclin D lead to
increased CDK4 and CDK6, increases CDK1/2 and Cyclins A, B, E
37
Bad is active when it is _________
nonpohosphorylated (AKT regulates)
38
what does MAP Kinase activate
AP-1 (jun and fos) and induction of myc and fos
39
what is guardian of the genome
p53
40
Familial adenomatous polposis is associated with
APC
41
Lynch syndrome is associated with which genes
MLH1, MSH2
42
describe cell proliferation of retinoblastoma
GF, Cyclin D, CDK4/CDK6, phosphorylates RB/E2F complex, E2F breaks away and enters nucleus to begin proliferation
43
DNA damage triggers an _______ in p53
increase
44
what does p53 stimulate
transcription of p21
45
what is MDM2
how p53 downregulates itslef
46
what happens when there is a loss of APC function
B catenin is not degraded, leads to cell prolifersation
47
how to identify autosomal recessive inheritance
if both parents have the disorder, all kids will have it
| not seen in every genration
48
what type of disease is xeropderma pigmentosum
auto recessive
49
what are indications for auto dominant
two affected parents may ahve unaffected offspring
| approx half of children will have disease w/ one affected parent
50
huntingtons disease is an example of
auto dom
51
X linked recessive is more commonly displayed in ______. an example
males; hemophilia A
52
An indication for X linked dominatn. example
father cannot pass to sons, but all daughters are affected. congenital hypertrichosis
53
how many repeats puts you at risk for huntingtons
40
54
HOXD13 mutations lead to
syndactyly
55
limb buds arise deep to
apical epidermal ridges
56
limb buds grow by proliferation of
mesenchyme
57
muscles of head, SKM, skeleton (exceot cranium), dermis and connective tissue arise from
praraxial mesoderm
58
epidermis, hair, skin,nails arise from
ectoderm
59
AER forms at site of
FGF10
60
AER secrets
FGF8, FGF4
61
WNT mutations cause
osteogenesis imperfecta
62
what is responsible for separating webbing
apoptosis
63
limb development occurs weeks
4-8
64
upper limbs rotate _______, lower limbs rotate ______
dorsally, ventrally
65
what is ectrodactyly
lobster claw
66
another name for phocomelia
flapper babies
67
what does NMJ include
motor end plate, axon terminals, synaptic cleft
68
what are another name for vSNARE
synaptobrevin and synaptotagmin (calcium sensor)
69
what is another name for mSNARE
syntaxin 1A, SNAP-25
70
what is the difference between end plate potential and action potential
ligand gated vs voltage gated
71
where is RYR1, RYR2, and RYR3 found
SKM, cardiac muscle, SKM
72
what does DHPR do
senses voltage change
73
what does troponin I do
inhibits the binding of myosin
74
what does troponin T do
binds to tropomyosin
75
what does troponin C do
binds calcium
76
which potential is all or non
action (voltage gated)
77
which potential is a graded potential
motor end plate (ligand gated)
78
a single contraction with increasing force with each subsequent twitch
treppe
79
hypocalcemia leads to _______
tetany (increases excitabiity)
80
a muscle with longer length =
greater velo, less force
81
a muscle with shorter length =
greater force, less velo
82
a fusiform muscle has a ______ length
greater
83
a pennate muscle has a _______ length
shorter
84
what is the order muscle fibers are recruited
type 1, type 2a, type x, type 2 B
85
power output =
force x velocity
86
main causes of fatigue (4)
1. CNS fatigue
2. Anaerobic metabolites
3. depletion of ATP/glycolysis
4. electrolyte loss
87
what are the two types of smooth muscle
unitary (single) or multiunit
88
in smooth muscle, calcium binds to ________ to activate _________
calmodulin, myosin light chain kinase
89
what are the sources of Calcium in smooth muscle
1. ECF
2. Ca induced Ca release
3. second messenger release from SR
90
what causes relaxation in smooth muscle
myosin light chain phosphatase
91
does smooth muscle contain sarcomere
no
92
Type I keratins are _______, type II keratins are _______
acidic, basic
93
the lowest energy radiation is
UVA
94
what is the steps p53 takes to produce melanin
p53, POMC, MC1R, cAMP, MITF, pigment
95
what are the types of barriers of the skin
physical, chemical, biological
96
what is the pH of the skin
4.7
97
what is the average weight of the skin
3.3 kg
98
what are the layers of the dermis
papillary and rheticular
99
what kind of tissue is in the papillary layer
aerolar connective tissue
100
what kind of barrier protects against bacterial growth and UV radiation
chemical
101
where are the thermoreceptors for body temp
hypothalmus
102
eccrine sweat glands function is
thermoregulation
103
vernix caseosa contains ______
sebum
104
melanocytes are usually found in the
basal layer
105
the dermis develops from _________ , which is derived from
mesenchyme, mesoderm
106
a clown patterned skin condition
harlequin ichthyosis
107
a lack of melanin in patches of the skin
piebaldism
108
T/F cardiac muscle does not divide
true
109
what provides electrical connection in cardiac muscle
gap junctions
110
increasing length of sarcomere affects
preload
111
NE/EPI increases Ca avalibity, which leads to
increased contractility
112
Ach leads to _______ contractility
decreased
