Flashcards in LG2.12 Glutamate Biochemistry Deck (19)
What types of receptors does Glutamate have?
i. Ionotropic Receptor
ii. Metabotropic Receptor
What are the three glutamate Ionotropic receptors?
NMDA, AMPA, Kainate
What is the metabotropic Receptor?
What fraction of neurons in the CNS are signaled by the neurotransmitter glutamate?
What neurotransmitter is the primary excitatory and most prevalent in the CNS/PNS?
What is EEAT?
Excitatory Amino Acid Transporters
What do EEAT do?
-Actively transport glutamate and aspartate (with sodium) out of extracellular space to keep synapse sensitive to next signal and to protect brain from excessive stimulation and neuronal death
Where are EEAT located?
On endothelial cells, postsynaptic neuron, and presynaptic neuron
How is glutamate gradient affected by ischemia?
a. Low oxygen and low glucose of ischemia depletes ATP.
b. Low ATP leads to decreased activity of Na+/ATPase pumps
c. Loss of Na+ gradient disables active transport of glutamate.
d. Leaking of glutamate leads to high extracellular glutamate causing
e. Excess signaling, seizures, and neuronal cell death.
What is Gluten?
-Group of proteins in wheat; structure and elasticity is useful in baking.
What is Glutamine?
The most prevalent amino acid found in gluten about ¼ of all amino acids. A five carbon a-amino acid that has an amide side chain
What is Glutamate?
A five carbon a-amino acid that has a carboxylic acid side chain
What is alpha-ketoglutarate?
-A five carbon a-keto acid that has a carboxylic acid side chain
What does Glutamine synthetase do?
Glutamate to Glutamine using ATP
What does Glutaminase do?
Glutamine to Glutamate, no ATP used
What is Glutamate dehydrogenase?
Glutamate to alpha-ketoglutarate
Which is higher in energy Glutamate or Glutamine?
a. Glutamate is a breakdown product of glutamine because glutamine is higher in energy
b. Glutamate is more oxidized and lower in energy than glutamate
How is Glutamate involved with the Cirtic acid Cycle?
- Citric acid cycle intermediates are transaminated into amino acids
- Citric acid cycle intermediates are readily replenished in the brain by its supply of glucose. In addition, glutamate can readily be converted to a-ketoglutarate.