In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Glomerular epithelial protein 1 ( GLEPP1 ) is a podocyte receptor membrane protein tyrosine phosphatase located on the apical cell membrane of visceral glomerular epithelial cell and foot processes .
### Output Text:
Glomerular epithelial protein 1 ( GLEPP1 ) is a podocyte receptor membrane protein <span class="chemical">tyrosine</span> phosphatase located on the apical cell membrane of visceral glomerular epithelial cell and foot processes . 