Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > Neurotransmitters 4 > Flashcards

Neurotransmitters 4 Flashcards

1
Q

serotonin synthesis and breakdown

A

same as norepinephrine from tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • produced in the pineal gland in response to the light–dark cycle level in the blood rising in a dark environment
  • organizing seasonal and circadian rhythms
  • melatonin may also be involved in regulating reproductive functions
A

melatonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

melatonin neurotransmitter is also synthesized from

A

tryptophan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

within brain is produced both by mast cells and by certain neuronal fibers

A

histamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

synthesis of histamine

A

from histidine in a single step enzyme histidine decarboxylase requires pyridoxal phosphate, and its mechanism is very similar to that of DOPA decarboxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

activation of the exocytotic release of histamine

A

depolarization of nerve terminals activates the exocytotic by voltage-dependent as well as a calcium-dependent mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

breakdown of histamine in brain

A

deactivated by methylation, then oxidation by MAO-B, followed by an additional oxidation step.

SAM (S-adenosylmethionine) converts to through said methylation SAH (S-adenosylhomocysteine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

breakdown of histamine in peripheral tissues

A

undergoes deamination by diamine oxidase, followed by oxidation to a carboxylic acid

no methylation like in the brain thats the big difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

acetylcholine is synthesised from

A 
acetyl CoA and choline by the enzyme 
choline acetyltransferase (ChAT).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

acetylcholine is stored in and released through

A

vesicles and later released through calcium-mediated exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

derived from the hydrolysis of phosphatidylcholine in membrane lipids

A

acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

acetylcholine is inactivated by

A

acetylcholinesterase enzyme

products are acetic acid and choline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the major neurotransmitter at the neuromuscular junctions

A

acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

excitatory neurotransmitter within the central nervous system leading to the depolarization of neurons

A

glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

does not readily cross the blood-brain barrier

A

glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

γ-aminobutyric acid

A

gaba

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

gaba

A

major inhibitory neurotransmitter in the central nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

gaba is synthesised by the

A

decarboxylation of glutamate in a single step catalyzed by the enzyme glutamic acid decarboxylase (GAD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

glutamate is synthesised

A

de novo from glucose/α-ketoglutarate (via enzyme glutamate dehydrogenase or through transamination reactions)

20
Q

gaba is recycled in the central nervous system by

A

a series of reactions called the GABA shunt which conserves glutamate and GABA.

21
Q

uptake of gaba occurs in

A

glial cells

22
Q

transporter of glutamate between cells in the CNS

A

glutamine

23
Q

mechanism of gaba shunt in glial cells

A

glial cells produces glutamate, which is converted to glutamine and transported out of the glial cells to neurons, where it is converted back to glutamate

24
Q

lack GAD and cannot synthesise GABA

A

glial cells

25
Q

excitatory neurotransmitters

A

aspatate and glutamate

26
Q

aspatate synthesised from

A

oxaloacetate via transamination reactions

27
Q

cannot pass blood brain barrier

A

aspatate

28
Q

involved in learning and memory processes as well as motor functions

A

excitatory amino acids aka (glutamate and aspartate)

29
Q

prolonged stimulation of neurons by excitatory amino acids results in neuronal death or injury overexcitatory effects result in

A

alzheimer’s disease

30
Q

major inhibitory neurotransmitter in the spinal cord

A

glycine

31
Q

glycine is synthesised

A

in neurons synthesized de novo within the nerve terminal from serine by the

enzyme serine hydroxymethyltransferase

which requires folic acid

32
Q

glycine inactivation

A

via uptake by a high-affinity transporter

33
Q

controls vasodilation neurotransmission and the ability of the immune system to kill tumor cells and parasites

A

nitric oxide (NO)

34
Q

nitric oxide is synthesised from

A

arginine by nitric oxide synthase

35
Q

what in smooth muscles cells leads to the relaxation of smooth muscle and the subsequent dilation of vessels

A

cGMP activation of protein kinases

36
Q

what leads to an increased in cellular cGMP

A

nitric oxide activation of a soluble guanylate cyclase
(a lyase enzyme that converts guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP) and pyrophosphate part of the G protein signaling cascade that is activated by low intracellular calcium levels and inhibited by high intracellular calcium levels)

37
Q

can easily cross cell membranes

A

nitric oxide because its a gas

38
Q

nitric oxide quirks

A
  • not stored in vesicles
  • not released by calcium-dependent exocytosis (it diffuses)
  • no active process that terminates its action
  • decays spontaneously
  • does not interact with receptors on target cells
  • action is not confined to the conventional presynaptic-postsynaptic direction
  • retrograde messenger and regulates the function of axon terminals presynaptic to the neuron in which it is synthesised
39
Q

nitric oxide inhibitor

A

hemoglobin and other heme proteins which bind it tightly

40
Q

cofactor and coenzyme for all three NO isoforms

A

BH2 as a cofactor (Tetrahydrobiopterin (BH4, THB)

(NADPH) as a coenzyme

41
Q

any of two or more functionally similar proteins that have a similar but not identical amino acid sequence and are either encoded by different genes or by RNA transcripts from the same gene which have had different exons removed.

A

isoforms

42
Q

site : neurons and epithelial cells
activated by : influx of extracellular calcium
enzyme : nitric oxide syntheses (nNOS)

A

Isoform I

43
Q

site : macrophages and smooth muscle cells
induced by : cytokines
enzyme : inducible form of nitric oxide synthase (iNOS)

A

Isoform II

44
Q

site : endothelial cells lining and blood vessels
activated by : influx of extracellular calcium
enzyme : endothelial nitric oxide synthase

A

Isoform III

45
Q

function contributes to pathogen killing and has immune-regulatory effects such as inhibiting T cell activity

A

iNOS

Biochemistry (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions