Biology 172 - Lecture 34

Front 1

What are 3 things plant cells have that animal cells lack?

Back 1

Vacuoles, Cell Wall, and chloroplasts

Front 2

What are adjacent plant cells attached by?

Back 2

Plasmodesmata

Front 3

Meristematic tissue

Back 3

Rapidly dividing, undifferentiated, responsible for continued growth

Front 4

Dermal Tissue

Back 4

Single layer of cells covering plant that secrets a waxy cuticle (which reduces evaporation and barrier against pathogens)

Front 5

Ground Tissue

Back 5

the bulk of plant body, complex (several types of cells, many specialized for structural support with a secondary cell wall)

Front 6

Vascular Tissue

Back 6

specialized for long-distance transport of water and nutrients

Front 7

Xylem

Back 7

conducts water and ions from root system to shoot system

Front 8

Phloem

Back 8

Conducts sugars, amino acids, chemical signals, etc. through plant body

Front 9

Where is meristematic tissue located?

Back 9

In the leafs and roots

Front 10

Where are all types of tissues, except meristematic tissue, located?

Back 10

In the Stem and Root (Vascular runs through - red; Ground tissue is the bulk - gray)

Front 11

Tracheids/vessel elements

Back 11

water-conducting cells found in xylem; tracheids have pits and adjacent to them are vessel elements that have larger perforations. Water moves both vertically and laterally through them.

Front 12

Phloem

Back 12

Contain companion cells and sieve-tube members

Front 13

Companion cells

Back 13

contain all the ogranelles found in a plant cell; they are not conducting cells but provide material to maintain the cytoplasm and plasma membrane of sieve-tube members.

Front 14

Lignin

Back 14

If secondary cell walls have lignin, they are very tough and rigid. **Feature of xylem

Front 15

Xylem is _____ at maturity; Phloem is _______ at maturity

Back 15

dead; alive

Front 16

Parenchyma cells

Back 16

Lack secondary cell wall

Front 17

Transpiration

Back 17

Acquiring CO2, and releasing O2 through the stomata

Front 18

Photosystem II

Back 18

Oxidized water to replace electrons it sends to the ETC

Front 19

How does water move from roots to leaves?

Back 19

Through a passive mechanism that does not require any expenditure of ATP. Water is moving DOWN the potential gradient (high to low)

Front 20

Osmosis

Back 20

Movement of water with low solutues into a cell with solutues.

Front 21

Turgor pressue and cell wall pressure

Back 21

Resists the movement of water into the cell to dilute its solutes by turgor pressure (caused by increase in volume of cell) and subsequently, wall pressure that pushes back with equal force.

Front 22

Water potential gradient

Back 22

Exists between the soil (high), plants, and atmosphere (low)

Front 23

Apoplastic vs. Symplastic routes

Back 23

A - within porous cell walls; S - through cells via plasmodesmata

Front 24

Xylem can act as a capillary tube. What three forces enable this?

Back 24

Surface tension, Cohesion, and Adhesion. HYDROGEN BONDING of H2O

Front 25

Menisci and water travel

Back 25

The formation of a meniscus at a water-air surface allows for water to be pulled up from the roots.

Front 26

Cohesion-tension theory

Back 26

Water is pulled through the xylem in continuous columns due to bonding between water molecules and the pulling forces generated by transpiration.

Front 27

Translocation

Back 27

Sugars move along their concentration gradients from source to sinks

Front 28

How do sugars move?

Back 28

Through vascular bundles of phloem.

Front 29

Translocation is the direction of movement during the active growing season of __________.

Back 29

Photosynthesis

Front 30

Source leaves and Sink relationship

Back 30

Source leaves send sugars to areas on the same side they are located on.

Front 31

Pressure-Flow Hypothesis

Back 31

Sucrose leaves source cell by active transport and enters companion cell. The concentration of sucrose in phloem at leaves is high, while the concentration of solutues in xylem at leaves are low. Water moves through sieve-tube, creating a flow of sucrose in the phloem down to sink cells. As water moves in, turgor pressure in phloem source increases. Cells at sink remove sucrose - solute potential decreases between xylem and sieve-tube and water potential in phloem near sink increases, resulting in water moving back into xylem.

Front 32

Cotransporters

Back 32

Symporter - carry two molecules in the same direction against concentration gradient (high to low). Antiporters carry two molecules in opposite direction.

Front 33

Phloem Loading at Sources: Active Transport in Companion cells

Back 33

Inside phloem cell, a proton pump transports protons to the outside of phloem cell, where it is used in a cotransporter to symport sucrose back inside the phloem cell. **Sucrose is coming from the leaf cell (passive transport of sucrose out of the leaf)