O processo de excreção permite que o homem se livre de substâncias que são tóxicas e inúteis ou que estão em excesso. Em condições fisiológicas normais, uma pessoa saudável deve eliminar, na urina: a. Agua, uréia, sais minerais e pigmentos. b. Agua, ácido úrico, proteínas e glicose. c. Agua, uréia, glicose e sais minerais. d. Agua, proteínas, sais minerais e pigmentos. e. Agua, amônia, hormônios e polissacarídeos.

a. Water, urea, mineral salts and pigments

Explanation:

The composition of urea of a normal healthy human consist of Water, urea, mineral salts and pigments. The water which is present in excess amount in our body will be removed by the body. Our body need salts in low amount which is taken from the food while the excess amount of salts and some pigments in the foods are also removed through the process of excretion and added into the urine. Due to these pigments, the color of urine is yellowish.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure