During the asexual blood stage, participates in initial cleavage of native host hemoglobin (Hb) resulting in Hb denaturation (PubMed:8844673, PubMed:11782538, PubMed:15574427). May cleave preferentially denatured hemoglobin that has been cleaved by PMI (PubMed:8844673). Digestion of host Hb is an essential step which provides the parasite with amino acids for protein synthesis, and regulates osmolarity (Probable). Hydrolysis of the bonds linking certain hydrophobic residues in hemoglobin or globin. Also cleaves small molecules substrates such as Ala-Leu-Glu-Arg-Thr-Phe-|-Phe(NO2)-Ser-Phe-Pro-Thr. Inhibited by pepstatin A. Component of the hemozoin formation complex (HFC) composed of falcipain 2, plasmepsins PMII, PMIII/HAP and PMIV, heme detoxifying protein HDP and falcilysin FLN. The HFC complex is involved in hemoglobin degradation and detoxification of heme in the food vacuole during the asexual blood stage. At the beginning of the asexual blood stage, the transmembrane zymogen is transported to the cytostome, an endocytic structure spanning the parasite cell membrane and the parasitophorous vacuole membrane where host proteins such as hemoglobin are endocytosed (PubMed:9169469). Following endocytosis, localizes to the cytostome vacuole membrane to be then delivered to the digestive (or food) vacuole where it is cleaved into the soluble and active enzyme (PubMed:9169469). In trophozoites, localizes to the digestive vacuole, an acidic vacuole where host hemoglobin is digested (PubMed:9169469, PubMed:11782538). Expressed during the asexual blood stage; expression begins in late rings, increases in trophozoites and continues in schizonts (at protein level). Not N-glycosylated. Proteolytically cleaved into the soluble active mature form in the digestive vacuole by cysteine protease falcipains; the process begins at the early ring stage (PubMed:9169469). Proteolysis requires an acidic environment (By similarity). In absence of falcipains, autoprocessing may serve as an alternate activation system (By similarity). Belongs to the peptidase A1 family.