Plant Transport, Nutrition, and Metabolism

What do plants need?

Light, CO₂, H₂O, Minerals, O₂H

How do water and minerals transport in plants

Root to shoot

What direction transport does water and minerals move in plants

Unidirectional transport

How does food move in plants

Multiple directions!

How do bryophytes transport water?

Diffusion

Transport routes of large plants

In/Out of individual cells, within tissues, long distance

What are the processes when transporting water in/out cells

Passive and active transport

How does PASSIVE TRANSPORT use ATP

Doesn’t use! Down concentration gradient

How does ACTIVE TRANSPORT use ATP

Uses it! Against concentration gradient

What is chemiosmosis

Using active and passive transport

What is the water potential level in osmosis when there is a high concentration of solutes

Low water potential

What is the water potential level in osmosis when there is a low concentration of solutes

High water potential

In osmosis, water potential moves from ___ to ____

High; Low

What type of solution is a turgid cell typically in

Hypotonic

Hypotonic solution

Low solute concentration : High water potential

What type of solution is a plasmolyzed cell in

Hypertonic solution

Hypertonic solution

High solute concentration : Low water potential

What type of solution is a flaccid cell in

Isotonic solution

Isotonic solution

Equal solute concentration : Equal water potential

Components of water potential

Water potential = Solute potential (-) + Pressure potential (±/-)

Sign of solute potential

Negative

Sign of pressure potential

Negative or positive

Tissue-Level Transport: Transmembrane

Molecules repeatedly cross plasma membranes and cell walls

Tissue-Level Transport: Symplastic

Molecules move through the symplast

Tissue-Level Transport: Apoplastic

Molecules move through the apoplast

What is this part of the dicot root

Epidermis

What is this part of the dicot root

Cortex

What is this part of the dicot root

Stele

What is this part of the dicot root

Endodermis

What is this part of the dicto root

Pericycle

What is this part of the dicot root

Xylem

What is this part of the dicot root

Phloem

Function of the Casparian strips

Regulates mineral transport through intracellular spaces

Steps in plant transport

Creation of membrane potential and proton gradient —> Chemiosmosis —> Water uptake and osmosis

What is root pressure created by

Flow of water into stele

Pressure can drive water ___ without transpiration

UP

Guttation

Leaking of water out of tips of vasculature tips in leaves due to root pressure

Transpiration

Movement of water through plant, driven by evaporation

What type of environment causes LESS evaporation

Dry, hot air climate

What type of environment causes MORE evaporation

Moist, cool air climate

What powers the movement of water from roots to leaves

Water pressure gradient

What is transpiration regulated by

Stomata!

Stomata

Little pores in surfaces of leaves

Closed stomata

Empty of water, flaccid, deflated

Open stomata

Full of water, turgid

How do plants open/close stomata

Uses active transport

What is the first step in stomatal closing

Potassium ions moveout of the vacuole and out of the cells

What is the second step of stomatal closing

Water moves out of the vacuoles, following potassium ions

What is the third step of stomatal closing

Guard cells shrink in size

What is the fourth step in stomatal closing

Stoma closes

What is the first step of stomatal opening

Potassium ions move into the vacuoles

What is the second step of stomatal opening

Water moves into the vacuoles

What is the third step of stomatal opening

Guard cells expand

What is the fourth step of stomatal opening

Stoma opens

How does water get to the stomata?

Xylem and Phloem tissues

What are xylem called in gymnosperms

Tracheid

What are xylem called in angiosperm

Vessel element

Wood, aka:

Secondary xylem

Components of tracheids

End wall, pits

Characteristics of vessel elements and tracheids

Dead at maturity, thick cell walls

What cell type are xylem

Sclerenchyma

Transport in phloem

Organic molecules and some minerals; Source to sink

Phloem transport status changes depending on ____

Conditions

Components of phloem

Sieve plate pore, sieve plate, sieve-tube element, companion cell

Characteristics of sieve-tube element

Lacks organelles, has cytoplasm

Characteristics of companion cell

Has nucleus(active), adjacent to STE, lots of connections to STE

Function of companion cell

Plays role in delivery of substances from sources into phloem, phloem to sink

Direction of companion cell

high to low OR low to high

Symplastic phloem loading

Passive transport

(Partly) Apoplastic phloem loading

Active transport

First step of transport in phloem

“Phloem Loading” of sucrose - ACTIVE/PASSIVE, water potential decreases in phloem, water enters

Second step of transport of phloem

Water absorption creates PRESSURE, forcing movement down pressure gradient - PASSIVE

Third step of transport of phloem

Pressure gradient maintained by “unloading” sucrose at sink (ACTIVE/PASSIVE)

Fourth step of transport of phloem

Water potential so water returns to xylem

What is long distance transport in xylem driven by

Transpiration, cohesion-adhesion-tension, water potential gradients

First step in plant metabolism

Energy converted in organized steps

Second step in plant metabolism

ATP generated and used

Third step in plant metabolism

Reducing power generated and used

Fourth step in plant metabolism

Requires membranes: Chloroplast, mitochondria

When does photosynthesis and respiration occur in plants during the day

Photosynthesis respiration (usually)

When photosynthesis and respiration occur in animals during the day

Respiration

When does photosynthesis and respiration occur in plants during the night

Respiration

When does photosynthesis and respiration occur in animals during the night

Respiration

________ alone can result in the transportation of water up a stem

Root pressure

_________ is the pull of water through the plant, driven by evaporation of water

Transpiration

__________ opens and closes and control the rate of transpiration

Stomata

___________ explains the movement of water in the _____

Cohesion-adhesion-tension theory; xylem

Phloem move materials from sources to sinks using ______ and the _______

Phloem loading; Pressure-flow hypothesis

Plant metabolism includes both _____ and ______

Respiration; Photosynthesis