The atmosphere is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface; data from the Mars Exploration Rovers indicate that suspended dust particles of roughly 1.5 micrometres diameter.
Glutamate is a powerful excitatory neurotransmitter that is released by nerve cells in the brain. It is responsible for sending signals between nerve cells, and under normal conditions it plays an important role in learning and memory.
L-glutamate is a substrate for the enzyme glutamic acid decarboxylase (GAD) which catalyzes the decarboxylation of L-glutamate to make gamma-aminobutyric acid (GABA). L-Glycine and GABA are inhibitory neurotransmitters and L-glutamate is an excitatory neurotransmitter. Understand the similarities and differences between receptors for excitatory and inhibitory amino acid neurotransmitters in terms of: mechanism of action (ligand-gated ion channels), subunit composition, and hydropathy profiles.