Cellular environment · proportions
A shared number sample: 40,000 water · 140 K⁺ · 10 Na⁺ · 10 Cl⁻ · 1 free Mg²⁺ · 5 ATP · 3 soluble-protein proxies. Colors follow this order: blue-gray, violet, amber, green, pink, pale gold, teal.
Assumed concentrations: water ≈40 M; K⁺ 140 mM; Na⁺ and Cl⁻ 10 mM each; free Mg²⁺ 0.7 mM (rounded to one marker); ATP pool 5 mM; protein proxy 3 mM (150 g/L at 50 kDa). ATP is mostly Mg-bound. Generic cellular estimates vary by cell and compartment; this selected mixture is not a complete ionic balance.
Water dominates molecule counts. Sizes are enlarged independently, motion is slowed, and this sparse sample does not reproduce molecular packing or measured diffusion. Lipids remain in membranes; background DNA/RNA and ribosomes are omitted from the abundance sample. The rounded nucleus is shown with a front cutaway, double envelope, representative pores and a nucleolus.
Cell composition · Intracellular magnesium / ATP · Nuclear envelopeDOPAMINE × DAT · ATOMIC CONTACTSOpposite charges anchor dopamine
The amine is usually NH₃⁺ near physiological pH. Asp79 presents COO⁻. Their N···O separation is 2.56 Å in 8Y2D, consistent with a salt bridge.
C · dopamineNOC · protein
Solid sticks: covalent bonds
Dashed lines: noncovalent contacts
1 Å = 0.1 nanometres
Experimental heavy atoms from human DAT–dopamine, PDB 8Y2D (2.80 Å). Charges reflect usual physiological protonation. Hydrogen positions are not resolved; polar distances alone do not establish hydrogen bonds. Dopamine binds and is transported without being chemically converted.Inspect the experimental structure ↗