Organelle Ecology - Chloroplasts

Question 1

importance of regulating the number, size, distribution of chloroplasts

Answer 1

want to have the right amount of stuff so enough co2 can get into chloroplasts- want the right surface area, and the best conformation to capture as much as poss

Question 2

important protein in plastid division

Answer 2

FtsZ ring (inner)- an outer ring then joins
MIN system important to ensure central placement

Question 3

stromule

Answer 3

tubular structure arising from plastids, connect plastids and allow passage of molecules e.g. for photorespiration

Question 4

stromule formation mechanism

Answer 4

overexpression of chloroplast outer membrane proteins

Question 5

stromules and immunity

Answer 5

stromules can be induced by immune signalling molecules like SA
stromules can then attach to the nucleus and move molecules in- e.g. ROS

Question 6

mechanisms for movement of chloroplasts

Answer 6

Phot2 photoreceptors detect local strong light, eventual CHUP1 activation, which initiates actin activity, allowing movement towards where weaker light is being detected

Question 7

details of MIN system

Answer 7

MinD forms caps at alternating ends every 1-2 minutes, disassembled by MinE, allowing midpoint to be easily determined

Question 8

other organelles stromules associate with

Answer 8

ER for exchange of metabolites
mitochondria for photorespiration via perioxome