The Protist Kingdom consists of mostly unicellular organisms that can have characteristics similar to plants, animals or fungi. Characteristics of Protists: mostly unicellular, few multicellular, eukaryotic, can be heterotrophic or autotrophic.Ex: algae, Paramecium, kelp (multicellular). î î î.he Protist Kingdom consists of mostly unicellular organisms that can have characteristics similar to plants, animals or fungi. Characteristics of Protists: mostly unicellular, few multicellular, eukaryotic, can be heterotrophic or autotrophic. Ex: algae, Paramecium, kelp (multicellular). î î î.
The active metabolites of codeine, notably morphine, exert their effects by binding to and activating the Î¼-opioid receptor. This occurs because opioids structurally mimic endogenous endorphins which are naturally found within the body and also work upon the Î¼-opioid receptor set.
Codeine is not itself centrally active, and must first be converted via first pass metabolism into morphine by the cytochrome P450 enzyme CYP2D6. Codeine is also metabolised into the inactive norcodeine via the CYP3A4 enzyme system.