Flashcards in week 4 Deck (63)
Loading flashcards...
1
Which amino acid does transcription always start with?
methionine
2
Which post translational modification targets protein for destruction?
ubiquitination
3
Describe lysosomal degradation
long half life
membrane proteins
extracellular proteins
4
describe proteosomal degradation
short half life
key metabolic enzymes
defective proteins
5
Describe primary proteins
sequence
6
describe secondary proteins
local folding
7
describe tertiary proteins
long-range folding
8
describe quarternary proteins
multimeric organisation
9
Describe supra molecular proteins
large scale assemblies
10
What is proteostasis?
protein homeostasis
11
What does proteostasis involve?
synthesis
degradation
localisation
trafficking
assembly
processing
folding
12
Describe alpha helix formation
results from h bonds forming between carbonyl oxygen atom of each peptide bond with the amide H atom from an amino acid 4 positions toward the C terminus
13
Describe an alpha helix
periodic spiral
confers directionality
R groups face outwards, covering the helix
14
Describe beta pleated sheet
each strand is 5-8 amino acid residues
H bonding between strands of polypeptide forms the planar sheey
directionally parallel or anti-parallel
R groups project from both faces of the sheet
15
Describe how secondary proteins form
stabilised by interactions between R groupd
hydrophobic interactions between non-polar R groups
hydrogen bonds between polar R groups
disulphide bonds
16
Describe how proteins normally fold
assemble into 3D conformation
determined by its primary structure
hydrophobicity is an important determinant for final conformation
17
What are some of the problems with protein folding?
considerable variation in time taken for a protein to adapt to final conformation
cellular environment is highly crowded
increased tendency for proteins to aggregate
18
What is a molecular chaperone?
any protein that interacts with, stabilises, or helps another protein to acquire its functionally active conformation, without being present in its final structure
19
how do molecular chaperones work?
selectively bind to short stretches of hydrophobic amino acids
20
What are some proteome maintenance functions of molecular chaperones?
de novo folding
oligomeric assembly
protein trafficking
proteolytic degradation
21
What is the enzyme that detects problems with protein folding?
glucosyltransferase
22
What does glucosyltransferase detect?
hydrophobicity
23
What are the stages of the ubiquitin proteasome system?
polyubiquitination
polyUb- protein recognised by CAP
polyUB removed; protein unfolded
protein threaded through proteasome
proteolysis
24
WHat is a proteinopathy?
accumulation of misfiled proteins resulting in aggregates, thereby gaining toxic activity or losing the normal function
25
What are the genes involved in early onset familial AD?
amyloid precursor protein
presenilin 1, 2
26
What is the gene associated with sporadic AD?
apolipoproteinE e4 allele
27
What are the 2 abnormalities in protein in the brain of someone with AD?
amyloid plaques in extracellular space
neurofibrillary tangles in cytoplasm
28
What is the change in amyloid shape associated with AD?
change from alpha helix to beta sheet
29
What are the main components of neurofibrillary tangles?
paired helical filaments - tau
30
What are the physiological actions of Tau?
neurite outgrowth
axonal transport
microtubule dynamics
31
What are the pathological actions of tau?
neuronal fibrillary tangles
microtubule dysfunction
cell death
32
What are involved on the phosphorylation of tau?
cdk5
GSK3beta
33
What is a proposed mechanism for tau aggregation?
detachment from microtubules
misfiled tau
pretangels
b sheeted sheet containing structures
neurofibrillary tangles
34
Describe dementia with lewy bodies
shares symptoms with AD and parkinson's disease
presence of cortical lewy bodies
alpha - synuclein aggregates
35
Describe a-synuclein in DLB
misfiling into beta pleated sheet structure that further aggregates into higher order insoluble structures; fibrils; the building blocks for lewy bodies
36
Describe transmissible spongiform encephalopathies
family of rare, progressive neurodegenerative disorders
loss of motor control and behavioural changes
can be inherited, sporadic or acquired
long incubation periods
characteristic changes associated with neuronal loss and failure to induce inflammatory resposnse
37
What is anterograde memory loss?
memory loss after disease sets in
38
What is retrograde amnesia?
old memories are forgotten
39
What is aphasia?
loss of language function
40
What is dysphagia?
impaired language function
41
What is agraphia?
loss of ability to write
42
What is alexia?
loss of ability to read
43
What is nominal dysphasia?
trouble naming objects
44
describe wernickes aphasia
fluent, fast, phonemic and semantic paraphasia, comprehension impaired, temporal lobe. receptive dysphasia
45
Describe brocas aphasia
non fluent, agramatic, phonemic paraphasias common, can't get words out, interior frontal lobe. comprehension is in tact
46
Where is important for visuospatial function?
right hemisphere
47
What is topographical disorientation?
dont know way around familiar environment
48
what is agnosia?
non recognition
49
what is prosopagnosia?
doesn't recognise face of people
may recognise smell, style of walking etc
50
What is included in cognition?
attention / orientation
memory
executive functioning
language
calculation
praxis
visuospatial ability
51
What are the different ways that attention can be classified?
arousal
sustained attention
divided attention
selective attention
52
What tests can be used to assess attention?
orientation in time and place
digit span
reciting months of the year backwards
serial 7s
spell world backwards
the STROOP test
53
What is the frontal lobe involved in?
goal setting and motivation
judgement control of inhibtion
flexibility and problem solving
planning / sequencing organisation
abstract reasoning
social behaviour
personality
54
Describe Wernicke's aphasia
fluent
phonemic and semantic paraphasia
comprehension impaired
Wernicke's area (temporal lobe)
55
Describe broca's aphasia
non-fluent
agramatic
phonemic paraphasias common
Broca's area (inferior frontal lobe)
56
What area of the brain is involved in calculation?
left hemisphere
angular gyrus in parietal lobe
57
WHat is acalculia?
inability to comprehend or write numbers properly
58
What is anarithmetria
difficulty with arithmetic
59
What types of dyspraxia are there?
errors in conception
errors in production
60
How can you test praxis?
imitation of gestures
orobuccal movements
use of imagined objects
lower limb apraxia
61
What are common problems associated with visuospatial deficits?
topographical disorientation
difficulties with dressing
mis-reaching for objects
visual neglect
visual object agnosia
prosopagnosia
62
WHat are the hallmark features of delirium?
impaired conciousness
hyperactive or hypoactive subtype
acute onset
change in cognition
visual hallucination
sleep-wake cycle
emotional changes
in most cases, evidence of underlying direct cause
63
