Trigger 10

Question 1

what is tryosine

Answer 1

precursor of all catcecholamines

synthesised from phenylaline

Question 2

describe the sysnthesis of catecholamine neurotrasmitted pathway

Answer 2

tryosine 
dihydroxyphenylaline 
dopmaine 
noradrenlaine 
adrenlaine

Question 3

where is dopamine most abundant

Answer 3

corpus straitum

Question 4

describe the nigrostriatal pathway

Answer 4

key dopamine pathway
cell body in the substaial nigra, moves up to corpus straitum
70% of dopmainic neurones are found here

Question 5

desrcibe the misocortical pathway

Answer 5

starts in VTA

through forebrain up to the cortex

Question 6

what happens in parkinsons

Answer 6

dopamine neurones are dyding

ridig muscles due to too much inhibtion of movement

Question 7

effect of less parkinsons on the motor coretx

Answer 7

the Dopamin neurones die which causes a redcution in inhibition
results in a overexcition of inhibitory signals to thalamus
reduction in glutamine so reduction in motor cortex leading to bradykinesia

Question 8

what is bradykniesa

Answer 8

suppression of voluntray movement

Question 9

why is L-DOPA used to treat parkinsons

Answer 9

Dopmaine is hydrophilic so cant cross BBB

L-DOPA is take pheripherally and can then cros the BBB where is it converted to dopamine

Question 10

How is dopamine broken down

Answer 10

broken down by homovanillic acid via DOPAC and 3MT

Question 11

what is the use of COMT

Answer 11

prevents L-DOPA being broken down into another dopamine precusor

Question 12

what is MAO-B used for

Answer 12

used in the treatment of depression and parkinsons

prevent the breakdown of dopamine

Question 13

what is alzhemirs

Answer 13

progressive neurodegeneration

most common cause of dementia

Question 14

symptoms of alzhemirs

Answer 14

• loss of memory, cognitive ability, communication
• changes in mood and personality
• forgetting recent events, unable to store new infotmaion in the temporal lobe

Question 15

what is huntingdons disease

Answer 15

progressive neurodegeration 
reduces lifespan (15-20yrs)

Question 16

symptoms of huntingdons

Answer 16

cognitive disorders - impulse control, task organisation. flexibilty, learning
movement disorder - involuntray jerking. twitching movements, rigidity, speech

Question 17

describe the ubiqutin protesome system

Answer 17

Ub activated by ubiquition-activiating enzyme (E1)
Ub then transferred to ubiqutitin-conjugating enzyme (E2)
protiens that are targeted for degreation have a region on them called degrons
E3 ubiquitin liages binds to degrons
Poly Ub signals for protesomal degredation
protein substrate in degraded, generting short peptides and free ubiquitin that can be resued

Question 18

describe apoptosis

Answer 18

programmed cell death 
membrane blebbing and cell seperates into membrane bound apoptoic bodies 
cell shrinks 
chromatin condenses 
nuclear DNA fragments 
attracts macropahges to phagocytose cell

Question 19

describe necrosis

Answer 19

usually uncontrolled and in respne to acute trauma
membrane blebbing
cell contents including lysosomes enzymes spill over inducing inflammaroty response and tissue degradeation
cells and organelles swell and burst

Question 20

describe the extrinsic apopotic pathway

Answer 20

Fas ligand binds to death receptor
protien recruitment and form death-inducing signalling complex
activatses caspase 8 (initator)
activates caspase 3 or 7 (exceutioner)

Question 21

describe the intrinsic pathway

Answer 21

cytotoxic stress
translocation of pro-apoptoic Bel-2 family to mitochondria
mitochondrial cytochrome C realesed
oligomerisation of pro-apoptoic factor Apf-1 - forms apoptosome
recruits caspse 9
activates caspase 3

Question 22

what is autopahgy

Answer 22

fromation of membrane bound structure
turns into an autophagosome
lysosom merges
autolysosome

Question 23

what is radio ligand binding

Answer 23

important when developing new drugs

the time a lignad binds to a receptor

Question 24

drug binding affinity

Answer 24

how likely it is for the drug to be bound to the receptor

longer time = greater affinity

Question 25

equation radio ligand binding

Answer 25

conc Drug x conc Receptor/ conc DR = kd

kd = dissocation constant

Question 26

describe competeive biding experiments radioligand binding assay

Answer 26

fixed conc radiolabel ligand with know bidning kinetics
incubated with increasing conc of unlabelled (competitive agonist/antagonist) drug B
creates a sigmoid curve log graph

Question 27

what is the IC50

Answer 27

amount of the new drug that is required to make 50% binding of the old drug

Question 28

what is the cheng-prusoff equation

Answer 28

IC50/(1+ (conc A/Ka)) = Ki

Ka =Kd of the old drug

Question 29

what dopmaine receptors are Gas

Answer 29

D1 ans D5

Question 30

what dopmaine receptors are Gi/Go

Answer 30

D2, D3, D4

Question 31

DNA methylation

Answer 31

the addition of a methyl group to one of the bases in the DNA chain, and is a key epigenetic modification.

Question 32

what are histones

Answer 32

Histones pack and order DNA into structures known as nucleosomes so that it fits within a cell’s nucleus.

Question 33

what is histone modifacation

Answer 33

Histone modifications are post-translational modifications that regulate gene expression

Question 34

what are non-coding RNA

Answer 34

are RNA molecules transcribed from the genome that do not encode proteins.

Question 35

what is Epigenetics

Answer 35

Epigenetics is the study of heritable changes in gene expression (active versus inactive genes) that do not involve changes to the underlying DNA sequence — a change in phenotype without a change in genotype — which in turn affects how cells read the genes.

Question 36

what is siRNA

Answer 36

Single-stranded RNA molecule (usually from 21 to 25 nucleotides in length) produced by the cleavage and processing of double-stranded RNA; binds to complementary sequences in mRNA and brings about the cleavage and degradation of the mRNA.