Chloroplast stroma
= Chloroplast stroma
The <chloroplast stroma> is the fluid compartment inside the <inner chloroplast envelope membrane> and outside <thylakoids>, containing <Calvin cycle> <enzymes>.<Biology 2e by Mary Ann Clark and others/8.1 Overview of Photosynthesis>[Biology 2e, 8.1, Figures 8.6–8.7: stroma and Calvin cycle location]{ref}
A <chloroplast stroma> location is therefore more informative than an unspecified “inside the <chloroplast>” location. In the boundary model above, entering <chloroplast stroma> has not yet entered <thylakoid lumen>. <Protein targeting> must distinguish these destinations; a fraction containing <chloroplasts> does not establish which internal compartment contains a detected <protein>.