BIOB10H3 Lecture Notes - Lecture 8: Red Blood Cell, Membrane Protein, Cyanobacteria
Document Summary
Chloroplasts: originated as cyanobacteria that lived as symbionts within eukaryotic cells (phagocytosis) still many similarities with cyanobacteria similar photosynthetic machinery can divide by binary fission. Chloroplasts: structure: a giant compared to other organelles! It is as big as a human red blood cell. Inner envelope membrane: stroma, thylakoid, grana = stacks of thylakoids, stroma lamellae which connects the grana. Outer envelope membrane: large channels = porin proteins: allows large molecules to get in and out. Inner envelope membrane: highly impermeable, variety of transporters, pumps and channels present. Downstream just means that the signal is located closer to the c terminus. All three (or two) signals together make the transit peptide target to chloroplast, then to stroma, then to thylakoid. To enter the chloroplast: the protein is unfolded by hsp70 in the cytosol the transit peptide then interacts with its receptor located close to the protein translocation channel on the outer envelope membrane.
