<P> Any proteins under roughly 30 kilodaltons can pass freely through the membrane, although there is some extra hindrance for negatively charged molecules due to the negative charge of the basement membrane and the podocytes . </P> <P> Any small molecules such as water, glucose, salt (NaCl), amino acids, and urea pass freely into Bowman's space, but cells, platelets and large proteins do not . </P> <P> As a result, the filtrate leaving the Bowman's capsule is very similar to blood plasma (filtrate or glomerular filtrate is composed of blood plasma minus plasma protein i.e. it contains all the components of blood plasma except the proteins) in composition as it passes into the proximal convoluted tubule . </P> <P> Measuring the glomerular filtration rate (GFR) is a diagnostic test of kidney function . </P>

Where does the filtrate go after it leaves the bowman's capsule