The table shows the concentration of amino acids in three different parts of a kidney nephron.
| Part of the nephron | Concentration of amino acids (mmol/dm3^{3}3) |
|---|---|
| Bowman's capsule | 4.5 |
| Start of proximal convoluted tubule | 4.5 |
| End of proximal convoluted tubule | 0.0 |
Explain one conclusion that can be made from this data.