1. Transport and Circulation

2. We’ll be discussing Cellular Transport
Plant Tissues and Transport in Plants
Trends and Various Strategies Used by Animals to Transport Materials
Transport in Man
Disorders of the Circulatory System

4. Membranes and cellular transport

5. Active vs Passive Transport

6. Transport of large molecules

7. Summary of Transport Processes
Diffusion
Osmosis
Facilitated Diffusion
Pumps
Endocytosis/exocytosis
Direction
High to Low
Low to High
N/A
Transport Mechanism
Pores
Channels
Membrane
Energy Required? No
Yes
Type of particle
Small, nonpolar
Water
Small-medium
Ions
Small-large
Examples of particles
CO2, O2
H2O
Glucose, fructose, Na+, Ca+2
Na+, K+, H+
Food, waste

8. Transport within the eukaryotic cell
Endomembrane system
Endoplasmic reticulum
manufacturing and transport facility
proteins produced in rough ER are packaged in vesicles
Golgi apparatus
modification and storage facility
receiving end and shipping end
Vacuole
large membrane bound sacs
usually stores undigested nutrients
Cyclosis/cytoplasmic streaming

9. Transport in Plants

11. Vascular tissues: xylem and phloem
Tracheids*
Vessel elements*
Parenchyma cells
Fiber
Phloem
Sieve-tube members
Companion cells
Sclerenchyma fibers
Both are continuous throughout the plant body

12. Transport occurs on three levels
Uptake and release of water and solutes by individual cells
Short-distance transport of substances by tissues and organs
Long-distance transport of minerals in water and sap within xylem and phloem by the whole plant body

13. A variety of physical processes are involved in the different types of transport
Sugars are produced by
photosynthesis in the leaves. 5
Through stomata, leaves take in CO2 and expel O2. The CO2 provides carbon for
photosynthesis. Some O2 produced by photosynthesis is used in cellular respiration. 4
CO2 O2
Light
H2O
Sugar
Transpiration, the loss of water
from leaves (mostly through
stomata), creates a force within
leaves that pulls xylem sap upward. 3
Sugars are transported as
phloem sap to roots and other
parts of the plant. 6
Water and minerals are
transported upward from
roots to shoots as xylem sap. 2
Roots exchange gases
with the air spaces of soil,
taking in O2 and discharging
CO2. In cellular respiration,
O2 supports the breakdown
of sugars. 7
Roots absorb water
and dissolved minerals
from soil. 1 O2
H2O
CO2
Minerals

14. Transport of ions at the cellular level depends on selectively permeable membranes
Controls the movement of solutes into and out of the cell
With specific transport proteins
Enable plant cells to maintain an internal environment different from their surroundings

15. Short-distance H2O transport from the soil to the root xylem occurs through diffusion

16. Water and minerals ascend from roots to shoots through the xylem Root pressure Transpiration–cohesion–tension theory
Tension – negative pressure

17. Stomata help regulate the rate of transpiration
Lower epidermal
tissue
Trichomes
(“hairs”)
Cuticle
Upper epidermal tissue
Stomata
100 m
Stomata help regulate the rate of transpiration
Leaves – broad surface areas
Increase photosynthesis
Increase water loss through stomata (transpiration)
Turgid
Flaccid

18. Turgid
Flaccid

19. Translocation – transport of organic molecules in the plant
Organic nutrients are translocated through the phloem (Pressure – Flow model)
Vessel
(xylem)
H2O
Sieve tube
(phloem)
Source cell
(leaf)
Sucrose
Sink cell
(storage
root) 1
Loading of sugar (green dots) into the sieve tube at the source reduces water potential inside the
sieve-tube members. This causes the tube to take up water by osmosis. 2 4 3
This uptake of water generates a positive pressure that forces the sap to flow along
the tube.
The pressure is relieved by the unloading of sugar and the consequent loss of water from the tube at the sink.
In the case of leaf-to-root
translocation, xylem recycles water from sink
to source.
Transpiration stream
Pressure flow
Translocation – transport of organic molecules in the plant
Phloem sap
Mostly sucrose
Sugar source  sugar sink
Source is a producer of sugar
Sink is a consumer/storage facility for sugar

20. Pressure – flow model high solute concentration at source
increase in hydrostatic pressure
sugars in sink draw water out of phloem