Did chloroplast and mitochondria used to be eukaryotic cells?

Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. ... Eukaryotic cells containing mitochondria then engulfed photosynthetic prokaryotes, which evolved to become specialized chloroplast organelles.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.