The table gives the content of glucose, urea and calcium ions in the blood entering the kidney, in
the glomerular filtrate and in the urine of a person.
Values are given in mg per 100 cm'.
Component / mg per 100 cm
Blood Glomerular filtrate
Urine
Component
glucose
100
100
0
urea
26
26
1820
calcium ions
4
4
5
a) i) Which of the components provides energy for
the body?

ii) Which of the components is a metabolic
waste product?

b) Explain why the figures for each component are the
same for the blood concentration and
glomerular filtrale.