What do plant cells/tissues need?
How do plants generate ATP for cellular work?
In glycolysis, a molecule of glucose is converted into two pyruvates and two NADH are produced. Two ATP, the body's source of energy, are used and four ATP are produced -- a net gain of two ATP.
What are the essential nutrients for plants and how do they use them?
How are these essential nutrients acquired?
How does bulk flow work?
sap in the vasc tissue
How does water potential drive transpiration?
(lowest negative pressure)
from soil ->trunk->leaf->airspace->outside air
Translocation, the movement of carbohydrates from their site of production to where they are needed, is accomplished through the pressure-flow theory. In this theory, sugar enters the sieve tube cells of the phloem, reducing the concentration of water inside. This causes water to osmose into the sieve tube in an attempt to balance the concentration. Meanwhile, where cells are using sugar, the concentration of sugar is falling. This leads to a concentration gradient from the leaves (where sugar production occurs) to the site where sugar is needed. Because the sieve tube cell walls are rigid, the entry of excess water causes pressure to rise. This causes the water in the phloem by the leaves to push away in an attempt to equalize the pressure -- at the same time carrying sugar with it.
Describe root pressure.
In this theory, water entering the root exerts a pressure on the water already in the xylem above it pushing it further upwards. Root pressure, however, also does not account for moving water large distances.