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: Liver injuries were quantified as serum activities of glutamate - oxaloacetate transaminase ( GOT ) and glutamate - pyruvate transaminase ( GPT ) .
### Output Text:
Liver injuries were quantified as serum activities of <span class="chemical">glutamate</span> - <span class="chemical">oxaloacetate</span> transaminase ( GOT ) and <span class="chemical">glutamate</span> - <span class="chemical">pyruvate</span> transaminase ( GPT ) . 