Phloem Flashcards
Describe the transport of carbohydrate in plants
At source cell sucrose is transported into the sieve tube, by co transport with H ions by companions cell.
This lower the water potential in phloem and water enters by osmosis.
Produces High hydrostatic pressure.
Mass flow transport surcose from site of photosynthesis to respiring cell.
Use your understanding of mass flow hypothesis to explain how pressure is generated inside this phloem tube.
Sucrose actively transported into phloem.
Reducing the water potential in phloem.
Water moves into phloem by osmosis from xylem.
Phloem pressure is reduced during the hottest part of the day. Use your understanding of transpiration and mass flow to explain why.
High rate of transpiration , so water lost through stomata.
Cause less water movement from xylem to phloem
