lecture 5

Question 1

what is CO2 converted into during photosynthesis?

Answer 1

sugars

Question 2

where does water uptake occur

Answer 2

at the roots

Question 3

what comes through the leaves

Answer 3

CO2

Question 4

what controls the short distance movement of substances

Answer 4

plasma membrane permeability

Question 5

passive transport absorbs what

Answer 5

water

Question 6

active transport absorbs what?

Answer 6

minerals

Question 7

what is the most important active transporter in the plasma membrane

Answer 7

proton pump

Question 8

what does the proton pump do?

Answer 8

1. pumps H ions (H+) out of cell
2. creates proton gradient bc H concentration is higher outside of cell than inside
3. creates membrane potential, inside of the cell is negatively charged relative to the outside

Question 9

besides water, what else do the root cells uptake

Answer 9

nitrate (NO3-)

Question 10

net uptake of or loss of water by a cell occurs by

Answer 10

osmosis

Question 11

what do aquaporins do?

Answer 11

facilitate diffusion of water; they are water channels that exist in vacuole and cell membranes, they speed up osmosis, without changing direction of water movement.

Question 12

water potential determines ______

Answer 12

direction of movement of water

Question 13

as turgor pressure increases, _______

Answer 13

pressure potential (wp) increases

Question 14

turgor pressure is the pressure exerted by the plasma membrane against the cell wall, and the cell wall against the _________

Answer 14

protoplast

Question 15

what is the protoplast?

Answer 15

the living part of a cell, it includes the plasma membrane

Question 16

plasmolysis occurs when…..?

Answer 16

when the protoplast shrinks and pulls away from the cell wall

Question 17

what is the apoplast

Answer 17

everything external to plasma memb. including cell walls, extracellular space, and INTERIOR of vessel elements and tracheids

Question 18

what is symplast?

Answer 18

it consists of the CYTOSOL of living cells, as well as the plasmodesmata

Question 19

why is efficient movement possible?

Answer 19

bc mature tracheids and vessel elements(xylem) are not alive so have no cytoplasm, and sieve tube elements (phloem) have very little organelles.

Question 20

unlike osmosis, bulk flow is independant of ____?

Answer 20

solute concentration

Question 21

what is the casparian strip

Answer 21

the belt of wax between cells and endodermis prevents water molecules to enter

Question 22

transpiration is a combination of? (4)

Answer 22

evaporation, cohesion, adhesion, negative pressure