Chapter 36: resource acquisition and transportation in plants

Question 1

Cotransport

Answer 1

Two molecules moving together, the cotransporter is the protein which allows cotransports to move in and out of the cell together

Question 2

Osmosis

Answer 2

Water moving from one place to another

Question 3

Solute potential

Answer 3

How much solute is being added to water

Question 4

Pressure potential

Answer 4

How much pressure is being exerted on the water

Question 5

Turgor

Answer 5

Plant cells take in water and become rigid

Question 6

Aquaporin

Answer 6

Channel in the cell wall, allows water to pass through the cell

Question 7

Symplast

Answer 7

Everything inside the cell

Question 8

Apoplast

Answer 8

The cell wall

Question 9

Bulk flow

Answer 9

The movement of water from the soil up through the plant to the leaf tissue through xylem

Question 10

Transpiration

Answer 10

Plant losing water through the stomata

Question 11

Sugar sink

Answer 11

A place where the plant loses more sucrose than it produces

Question 12

What is passive diffusion? Active transport?

Answer 12

Passive diffusion: Diffusion which requires no ATP to complete, oftentimes just letting molecules diffuse
Active transport: The plant does something (such as change the electricity on the side of a stomata) to move cells around

Question 13

What is a proton pump? What forms of potential energy does it create that can be used to do cellular work?

Answer 13

A proton pump pumps protons in and out of the cell, therefore making it positive or negative, which can attract certain cells and nutrients into the cell

Question 14

How can this energy created by proton pumps be used for the active transport of different solutes like ions and sucrose?

Answer 14

Most commonly, the ions will want to balance out the electrical charge inside and outside of the cell, so the proton pump will make the inside negative to attract cations inside of the cell, and anions to outside of the cell, sucrose in specific has a neutral charge, so for it to come in it first needs to attach to another molecule which will want to enter the cell, then both molecules will enter the cell through the cotransporter

Question 15

Define the term “water potential”

Answer 15

Water potential is just where the water will want to go, it can be found by subtracting the total amount of solutes in water from the amount of pressure which is being exerted onto the water

Question 16

How does water potential determine the direction of water movement?

Answer 16

Water will want to balance itself out so that its even all around, so if there is a lot of solutes in one side of a permeable membrane and no solutes on the other side, the water will move from the place with the low solutes to the one with high solutes so that the concentration is the same on both sides
high water potential to low water potential

Question 17

Be able to use the water potential equation for determining the movement of water in a defined system, i.e., between a plant cell and its aqueous environment.

Answer 17

Water Potential = Water pressure - Water solute

Question 18

What are the three major pathways of transport (routes) through plant cells?

Answer 18

Symplastic: Through the inner parts of the cell
Apoplastic: Through the cell wall
Transmembrane: It goes through the cell wall, into the symplast, then back into the cell wall, then into the symplast, over and over again

Question 19

What is the function of the Casparian strip?

Answer 19

It makes sure that no toxic substances can reach the xylem and infect the tree

Question 20

What process exerts the pulling force on water in the xylem of a plant that ultimately pulls water into the leaf?

Answer 20

Transpiration gets water to leave the plant, however that water leaving is also sticking to the other water molecules which can reach all the way down into the roots, so when something leaves by transpiration it pulls up all the water

Question 21

What properties of water make the movement of the xylem sap against gravity possible?

Answer 21

Cohesion: Molecules sticking to each other
Adhesion: Molecules sticking to a surface

Question 22

What are stomata? What is the mechanism responsible for their opening and closing?

Answer 22

Stomata close and open whenever the plants needs to lose less water, or needs to perform photosynthesis, the cells that allow them to do that are called the guard cells

Question 23

What are the stimuli for stomatal opening and closing?

Answer 23

1. Light hitting the plant
2. The leaf running out of CO2
3. The plants internal clock

Question 24

What is the effect of water deficiency on stomata?

Answer 24

If the stomata does not have enough water then it will close

Question 25

How does movement through xylem differ from movement through phloem?

Answer 25

The phloem moves a sort of sap, it has sugar sources and sugar sings, from the leaves to the sinks
The xylem, moves water and minerals, from the root to the top