Spiders have to absorb salts and wastes while humans have microscopic subunits in the kidneys called to filter blood. spiders have malpighian tubules to absord salts and wastes while humans have microscopic subunits in the kidneys called nephrons to filter blood.

Spiders have malpighian tubules to absorb salts and wastes while humans have microscopic subunits in the kidneys called nephrons to filter blood. Malpighian tubules remove wastes from insects by producing urine and solid nitrogenous waste, which are then excreted from the body.

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.