BIOL 220 Lecture Notes - Lecture 1: P680, Ferredoxin, Carbon Fixation
Document Summary
Plasmodesmata: physical connections between two plant cells, consisting of membrane-lined gaps in the cell walls through which the two cells" plasma membranes, cytoplasm, and smooth er can connect directly. Functionally similar to gap junctions is animal cells. The symplast of adjacent cells is often connected through plasmodesmata. Apoplast: the region outside the plasma membranes consisting of the porous cell walls and the intervening extracellular air space. Transpiration: loss of water vapor from aboveground plant parts. Occurs when (1) stomata are open, and (2) the air surrounding leaves is drier than the air inside leaves. Water moves from roots to leaves passively because of differences in the potential energy of water. Water potential ( ): the potential energy that water has in a particular environment compared with the potential energy of pure water at room temperature and atmospheric pressure. Under these conditions, pure water has a water potential of 0. Differences in water potential determine the direction that water moves.
