S
Chapter 5: Transport in Plants & Animals
Fundamentals of Biology, SEM II AY 2022-2023
Objectives
• To demonstrate:
✓ The different types of
transport systems in
plants and animals.
5.1 Membrane
permeability
structure
results
in
selective
• All cells have the plasma membrane
11)
i
• The plasma membrane is Selectively permeable:
✓ Allows some molecules in and keeps other molecules out.
✓ The structure helps it to be selective!
e
Lipids
bilayer
5.1 Membrane
permeability
structure
results
• Function of the membranes:
in
selective
in
-
• A steady movement of small molecules and ions moves across the
plasma membrane in both directions.
5,5 •
-x
Sugars, amino acids, and other nutrients enter the cell, and metabolic
waste products leave it.
=
out
in
I
• The cell takes in oxygen for cellular respiration and expels carbon
-
-
dioxide.
=
-
20+ waste.
• cell membranes are selectively permeable, and substances do not
cross the barrier as and when they like.
5.1 Membrane
permeability
structure
results
in
selective
2
-
• Importance of lipid bilayer:
• Consists of Hydrophilic heads and hydrophobic tails, which are
↳o
arranged in two layers and hence the name lipid bilayer.
• Polar molecules such as glucose and other sugars pass only slowly
-
↳•
rapid
•
through a lipid bilayer.
I
e
Water, an extremely small polar molecule, does not cross very
in
price
rapidly.
read
-
-Phot
Non polar molecules, such as
CO2
hydrocarbons, carbon dioxide, and
oxygen, can dissolve in the lipid bilayer
of the membrane and cross it with ease.
~
radquicen
5.2 Passive Transport
/
y
Transport
Passive
*
S
I
Active
5.2 Passive Transport
Passive Transport:
• Does not require energy.
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5
• Involves diffusion or facilitated transport.
• Carrier proteins are not required.
5.2 Passive Transport
Passive Transport
Diffusion
See
lipids
<salutes)
Osmosis
(water)
Facilitative Diffusion
Diffusion of water
molecules.
Diffusion with the
help of transport
proteins
(protein
carriers).
bilayers
-
con
A
5.2 Passive Transport
1. Diffusion:
->
from
cone
151
concentration
low
to
b
Conc
&
• In the absence of other forces, diffusion is the movement of a
substance from where it is more concentrated to where it is less
concentrated.
• Diffusion is associated with movement of solids, liquids or gases, but
not water.
• The molecules move down a concentration gradient.
-
• Diffusion continues until all molecules are evenly distributed
(equilibrium is reached).
5.2 Passive Transport
• Diffusion across a biological membrane is a spontaneous
process.
• One important example is the uptake of oxygen by a cell
performing cellular respiration.
• The diffusion of a substance across a biological membrane is
called passive transport because the cell does not have to
expend energy to make it happen.
5.2 Passive Transport
ahh#)>⑦@π?.
.
⑤
↑
b
-
M
b
-
-
5.2 Passive Transport
1.
high
low
solute
to
solute.
from high H20
to low H20 can.
2
2. Osmosis:
from
con
• Osmosis is diffusion of water from a
region of lower solute
concentration to that of higher solute concentration until the solute
concentrations on both sides of the membrane are equal.
• The molecules move down a concentration gradient.
• The diffusion of a water across a biological membrane (osmosis) is
called passive transport because the cell does not have to
expend energy to make it happen.
5.2 Passive Transport
Osmosis
↓
only water
A
>
-
B
5.2 Passive Transport
Osmosis in animal cells:
•
He0
•
8
·
&
↑
.....
H20
Shring
Same
Isotonic: If a cell without a wall, such as an animal cell, is placed in an
environment that is isotonic to the cell (iso means "same"), there
will be no net movement of water across the plasma membrane.
↑more
-> core
Hypertonic: if a cell is transferred to a solution that is hypertonic to
the cell (hyper means "more”), the cell will lose water to its
environment, thus it shrivels, and probably die.
•
Example : This is one reason why an increase in the salinity (saltiness) of a
lake can kill the animals there—if the lake water becomes hypertonic to the
animals' cells, the cells might shrivel and die.
bless -
•
&
I
⑨
d
&
D
·o
;555
conc
Hypotonic: If we place the cell in a solution that is hypotonic to the
cell (hypo means "less"), water will enter the cell faster than it leaves,
and the cell will swell and lyse (burst) like an overfilled water
balloon.
5.2 Passive Transport
Osmosis in animal cells:
Shrivel
normal
I
↳urstllest
5.2 Passive Transport
Osmosis in plant cells:
• Hypotonic: When water enters the cell , the plant cell swells as
water enters by osmosis, However, the elastic wall will expand only
so much before it exerts a back pressure on the cell that opposes
further water uptake. At this point, the cell is turgid.
• Hypertonic: When water leaves the cell, the plant cell shrivels
and the central vacuole becomes very small. This results in a process
called Plasmolysis.
• Isotonic: If a cell with a wall, such as a plant cell, is placed in an
environment that is isotonic, there will be no net movement of
water across the plasma membrane, or sometimes water moves in
both directions making it soft.This is called Flaccid condition.
5.2 Passive Transport
Osmosis in plant cells:
and
protect
plant
cell
rotonic Iertonein
5.2 Passive Transport
same
high
water
Low
H20
-
H2O
->
HO
L
*
-
-
Lysed
I
shriveled
mall
H20
↳ ↳
H20
-
E
->
&
->
↳
5.2 Passive Transport
3. Facilitated Diffusion:
• Many polar molecules and
ions blocked by the lipid
bilayer of the membrane
diffuse passively with the
help
of
transport
proteins.
• This movement of lipid
insoluble
molecules
through the membrane is
called facilitated diffusion.
5.3 Active Transport
Active Transport:
• To pump a molecule across a membrane against its gradient requires
work.
• In active transport, the movement of substances across membranes
is against concentration
concentration.
gradient
from
low
• Need energy in the form of ATP.
• Proteins involved in active transport are called pumps.
• Proteins use energy to move substances.
to
high
5.3 Active Transport
5.3 Active Transport
Active Transport - Pumps:
• Animals for active transport have sodium potassium pumps
especially in nerve and muscle cells.
• For example, compared to its surroundings an animal cell has a
much higher concentration of potassium ions and a much lower
concentration of sodium ions.
• The plasma membrane helps maintain these steep gradients by
pumping sodium out of the cell and potassium into the cell.
• Change in shape of the pump after attachment and detachment,
allows the movement of sodium and potassium ions.
Sodium Potassium pump:
Low
A
High
5.4 Bulk Transport
in
out
Bulk Transport (Exocytosis & Endocytosis):
• Moving large molecules (macromolecules) into & out of cell
through vesicle formation.
• Vesicle formation require energy.
• Examples:
✓ Exocytosis
✓ Endocytosis
• Phagocytosis: “cellular eating”
->
• Pinocytosis: “cellular drinking”
solid
->
• Receptor-Mediated Endocytosis
liquid
5.4 Bulk Transport
Exocytosis:
&55
• Vesicles fuse with plasma
-
membrane.
• The plasma membrane is
enlarged.
• Molecules move out of the
cell.
3-8
↳8:
5.4 Bulk Transport
passive
Endocytosis:
1.
↳ diffussich
Yes
I
Phagocytosis
solid
eating
2.
Pinocytosis
Liquid
drinking
3.
Receptor-mediated
endocytosis
speisis
fic
eng
->
5.4 Bulk Transport
1. Phagocytosis:
• It is the cellular process
of eating.
• Also called cell eating.
suraund
• It involves engulfing solid
particles by cell membranes.
S
digestion
5.4 Bulk Transport
2. Pinocytosis:
• It is when cell ingests
extra cellular fluid and
contents.
• Also called cell drinking.
• Forms invagination by cell
membranes.
• Releases fluid filled vesicles
in cytoplasm.
aking
as
5.4 Bulk Transport
3. Receptor-Mediated
Endocytosis:
•
It is a type of (pinocytosis)
in which specific molecules
are ingested into the cell.
•
Location of receptors on
the plasma membrane
called a coated pit.
•
Molecules first bind to
specific receptor proteins
•
Vesicle will form, contain the
molecules and their receptor.
Receptor
↑
-
Sted
Dixi
5
8
->
digestic
enzy
5.5 Plant structure, growth and development
Major Plant organs:
•
•
•
The three basic plant organs: Roots,
Stems, and leaves.
CO2
S
Light
Plant is divided into a root system and
a shoot system. Shoot system
consisting of stems and leaves.
Forms
-
-
Plants must absorb water and minerals
from below the ground and CO2 and
light from above the ground.
I
-
•
Roots will die without the organic
nutrients imported from the shoot
system.
•
Conversely, the shoot system depends
on the water and minerals that roots
absorbed from the soil.
-
-
7
minerals
is water
Basic
organs
↳root
↳ Stem
5.5 Plant
structure, growth and development
↳Leaves
Different types of Plant cells
plant systems
root
b
systems
woot)
bshoot systems
stem
Leaves
flowers
5.5 Plant structure, growth and development
Different types of Plant cells
loss of water from Learts
8
5.6 Vascular Transport in Plants
④
-
CO2 +HO-CHiO6
⑬
-
I
-
⑬
I
0
↑
-miniras
I
xylem (ap
One
CHOst
-
planted
.
#
-
zylem
①
⑳
>
Es
Respiring
mco2
-
M
↳Ar
On
+
Or
kloewyger
God's
1.
2
xylem -Root
phloem
to
leaves (water
leaves to all
and menral)
plant
5.6 Vascular Transport in Plants
& intere
be
Vascular Tissue (Xylem)
Xylem includes 2 types of dead, hollow,
tubular cells:
• Tracheid: These are long, thin tube
like structures without perforations
at the ends.
• Vessel elements: short, wide tubes
perforated at the ends (together
form a pipe, called vessel).
✓ (Both
cells have
sections on the walls)
pits
(thin
down->up
5.6 Vascular Transport in Plants
Vascular Tissue (Xylem)
Xylem includes 2 types of dead, hollow,
tubular cells:
• Tracheid: These are long, thin tube
like structures without perforations
at the ends.
• Vessel elements: short, wide tubes
perforated at the ends (together
form a pipe, called vessel).
✓ (Both
cells have
sections on the walls)
pits
(thin
5.6 Vascular Transport in Plants
Vascular Tissue (Phloem)
• Phloem cells are ALIVE!
(unlike xylem)
• Phloem composed of:
• Sieve tube members (STM)
• Companion cells
Xylem cells [dead]
5.6 Vascular Transport in Plants
Cell type
Tracheid
Vascular Tissue (Phloem)Long
Length
• Phloem cells are ALIVE!
Wedth
(unlike xylem)
Thin tube
• Phloem composed of:
No perforation at
ontube members (STM)
Perforati
• Sieve
the end (absent)
Pits
• Companion cells
Present
Vessel elements
Short
Wide tube
Has perforation at
the end (present)
Present
5.6 Vascular Transport in Plants
Sit
de
↳
dis
upword
000o
-
dan
0
Water and Minerals
0
Food
Xylem
Cell type
5.6 Vascular Transport in Plants
Phloem
One way
(up)
Two ways
(up+down)
Transported
material
H₂O + minerals
Sugar
(Food)
End walls
between cells
Absent
Present
(With perforation)
Type of cells
Trachied, vessel
element
(Dead)
STM
- companion cells
(Alive)
Direction of flow
Water and Minerals
Food
5.6 Vascular Transport in Plants
Types of transport in
plants:
Transport in plants occurs on
three levels:
• Cellular transport level
• Short-distance transport
• Long-distance transport
I
5.6 Vascular Transport in Plants
-
e
Types of transport in plants:
• Cellular level: uptake and loss of water and solutes by specific
cells (root hairs).
①it
• Short distance transport: Cell to Cell at
level of tissue or organ
cell
(loading sugar from leaf to sieve tube).
• Long distance transport: transport of [
sap within xylem and
phloem (whole plant).
5.6 Vascular Transport in Plants
Short-distance transport:
plasma
cellthat
↑5141
• Symplast route: connections between cells or plasmodesmata
-
have a continuous cytoplasm.
-
• Apoplast route: Area of cell wall provides a matrix through which
liquids may travel.
->
->
cell wall-cell
cytoplasom
membren
5.6 Vascular Transport in Plants
Long-distance transport
• Diffusion is much slow for long distance transport in a plant like those of
water and minerals.
• Long-distance is the transport of sap within xylem and phloem at the
level of the whole plant.
• Water & Solutes move through xylem vessel elements.
• Sugars (food) travels through sieve tubes.
• The process of movement in vessels and sieve tubes is called Bulk flow.
•
Bulk Flow: The movement of a fluid driven by pressure.
5.6 Vascular Transport in Plants
As
all
plants
Long-distance transport
->
push sugar
• In phloem, hydrostatic pressure (due to addition of sugar with water)
generated at one end of a sieve tube forces sap to the opposite end of
↳ phorem
the tube.
The place where the food is Prepared (Source- leaf)
The place where the food is stored or used (Sink).
In xylem it is tension (negative Pressure) that drives long distance
transport.
palling force
Transpiration: evaporation of water from a leaf reduces pressure in leaf
xylem.
Root pressure: creates pressure in the roots to push the water up.
cell
•
•
•
•
•
- >
↳
pushing
force
5.6 Vascular Transport in Plants
Pathway of water movement through xylem (by
Osmosis):
1.
Soil water enters the root through its epidermis.
2.
Water travels in two ways :
• The cytoplasm of root cells — called the symplast: crosses the
plasma
membrane
and
then
cell to cell through plasmodesmata
passes
from
• In the nonliving parts of the root — called the apoplast: in the
spaces between the cells and in the cells walls themselves. This
water has not crossed a plasma membrane.
5.6 Vascular Transport in Plants
Pathway of water movement through xylem (by
Osmosis):
3. The endodermis which is the inner boundary of the cortex
is impermeable to water.
4. Endodermis has a corky material running in horizontal and
radial direction called casperian strip.
xyem
5. Therefore, to enter the 1
stele I the Apoplastic water must
enter the symplasm of the endodermal cells.
6. From here it can pass by plasmodesmata into the cells of
the stele.
-
5.6 Vascular Transport in Plants
-j
↑
5.6 Vascular Transport in Plants
Transport of Water up the Xylem:
-> the
1. Root Pressure (pushing xylem sap)
- >
2. Transpiration (pulling xylem sap)
water and mineral
5.6 Vascular Transport in Plants
1. Root Pressure (pushing xylem sap)
• Root cells actively pump ions (by using ATP) into the xylem and
create a gradient allowing water to move into xylem.
• The accumulation of water in the xylem , creates a pressure,
called root pressure, which forces water upwards.
5.6 Vascular Transport in Plants
2. Transpiration (pulling xylem
sap)
• Loss of water from leaves is
called transpiration.
• Each molecule of water vapor
evaporates from stomata on leaf
surface, a new molecule comes
in.
• Second molecule replaces first.
• It depends on cohesive forces (in
water) and adhesive forces
(water & walls).
5.6 Vascular Transport in Plants
Transport of organic nutrients
• Carbohydrates manufactured in leaves or released from storage
organs are distributed through phloem by a process called
translocation.
• Phloem sap is made up of water and sucrose, In addition to
amino acids, other sugars and hormones
transported.
which are also
5.6 Vascular Transport in Plants
Source and Sink
• Source: where the sugar
starts its journey (either
where it is produced or
stored).
• Sink: where sugar ends up
(either where it is needed
or will be stored).
5.7 Plant Nutrition
Plants nutritional requirements
• Every organism continuously exchanges energy and materials with its
•
•
•
•
environment.
At the level of the ecosystem, plants and other photosynthetic
autotrophs perform the key step of transforming inorganic compounds
into organic compounds.
Plants need light as the energy source for photosynthesis. In order to
synthesize organic matter.
Plants also require raw materials in the form of inorganic nutrients:
water, minerals, and carbon dioxide.
For a typical plant, water and minerals come from the soil, while
carbon dioxide comes from the air.
5.7 Plant Nutrition
Macro and micro nutrient requirements
Macronutrients:
Micronutrients:
• Nine essential elements are called
macronutrients. Plants require them
in relatively large amounts.
• These include:
• Carbon
• Oxygen
• Hydrogen
• Nitrogen
• Phosphorus
• Sulfur
• Potassium
• Calcium
• Magnesium
• Eight elements are called
micronutrients. Plants require them
in relatively small amounts.
• These include:
• Chlorine
• Iron
• Manganese
• Boron
• Zinc
• Copper
• Nickel
• Molybdenum
5.7 Plant Nutrition
5.8 Animal Nutrition
Need to Feed
• All animals are heterotrophic in nature. We are dependent on a regular
supply of food.
• All animals eat other organisms—dead or alive, whole or by the piece.
• In general, animals fit into one of three dietary categories:
•
Herbivores: such as gorillas, cattle, hares, and many snails, eat mainly
autotrophs (plants and algae).
•
Carnivores: such as sharks, hawks, spiders, and snakes, eat other
animals.
•
Omnivores: regularly consume animals as well as plant or algal matter.
Omnivorous animals include cockroaches, crows, bears, raccoons, and
humans, who evolved as hunters, scavengers, and gatherers.
5.8 Animal Nutrition
5.8 Animal Nutrition
5.8 Animal Nutrition
Energy Supplements
• All animals as a result of various metabolic reactions produce ATP,
which is the energy currency of the cell.
• Nearly all of an animal's ATP generation is based on the
oxidation of energy rich organic molecules—carbohydrates,
proteins, and fats—in cellular respiration.
• Fats are especially rich in energy; the oxidation of a gram of fat
liberates about twice the energy liberated from a gram of
carbohydrate or protein.
5.8 Animal Nutrition
Ingredients of a balanced diet
• Essential amino acids
• Essential fatty acids
• Proteins
• Fat and water soluble Vitamins
• Minerals
5.9 Blood Composition and Function
Blood is composed of many components, but the four
most important ones are:
Red blood cell
White blood cell
• Red blood cells
• White blood cells
• Platelets-
• Plasma
2
3
Platelets
Plasma
5.9 Blood Composition and Function
Whole blood
Plasma (water)
(46-63%)
Cellular Elements
(37-54%)
1.
Plasma Proteins
(7%)
1.
Red Blood Cells
(99.9%)
2.
Water (92%)
2.
Platelets
3.
Other Solutes (1%)
3.
White Blood Cells
(0.1%)
5.9 Blood Composition and Function
Functions of Blood
1.
Transporting oxygen and nutrients to the lungs and tissues.
2.
Removing Carbon dioxide and wastes from all tissues
3.
Forming blood clots to prevent excess blood loss.
4.
Carrying cells and antibodies that fight infection.
5.
Bringing waste products to the kidneys and liver, which filter and
S
clean the blood.
6.
Regulating body temperature.
-
5.9 Blood Composition and Function
Red Blood Cells (Erythrocytes)
• They are relatively large microscopic
cells without nucleus.
• Occupy
40-50% of total blood
volume.
->
male
• In ♂, 1µL of blood contains 4.5-6.3
million RBCs.
femal
• In ♀, 1µL of blood contains 4.2-5.5
million RBCs.
5.9 Blood Composition and Function
White Blood Cells (leukocytes)
• Exist in variable numbers and types but make up a very small part
of blood's volume, normally only about 1%.
• A typical µL of blood contains 6000-9000 WBCs. Compare that to
RBCs
• There are five types of WBC namely:
5.9 Blood Composition and Function
Platelets (thrombocytes)
• Platelets or thrombocytes, are cell fragments
without nuclei.
• Function: clot blood at the site of wounds.
• They do this by adhering to the walls of
blood vessels, thereby plugging the rupture
in the vascular wall.
• They also can release coagulating chemicals
which cause clots to form in the blood that
can plug up narrowed blood vessels.
5.10 Blood Vessels Structure & Function
Blood vessels
• Arteries: Carry blood away from the heart.
• Veins: Carry blood to the heart.
• Capillaries: Connects arteries to veins.
S
5.10 Blood Vessels Structure & Function
Arteries and Veins
Arteries
Veins
Elastic in nature
Blood carried away from heart
More muscle, narrow lumen
Carry oxygenated blood
Pulmonary artery - deoxygenated
blood
• Largest artery (Aorta) from heart branches to small arteries
• Smallest arteries are called
Arterioles
• Arteries have no valves
•
•
•
•
•
•
•
•
•
•
•
•
Elastic in nature
Blood to the heart
Less muscle, wide lumen
Carry deoxygenated blood
Pulmonary vein - oxygenated blood
Smallest veins are called Venules
Venacava (largest vein) branches to
veins which branch then to venules.
• Veins have valves (to prevent back
flow of blood)
5.10 Blood Vessels Structure & Function
Arteries and Veins
5.11 Circulation and Gaseous Exchange
co2+ waste
• Every organism must exchange materials and energy with its
environment.
• The exchange ultimately occurs at the cellular level.
• The resources required by cells, such as nutrients and oxygen,
move across the plasma membrane into the cytoplasm, and
metabolic wastes, such as carbon dioxide, move out of the cell.
• In unicellular organisms, these exchanges occur directly with the
external environment.
• For multicellular organisms, however, direct exchange with the
environment is not possible.
5.11 Circulation and Gaseous Exchange
Human Heart: Blood circulation
• Heart is a pump that pushes blood to cells, organs and tissues.
• Blood delivers nutrients and oxygen and removes CO2 and wastes.
• Blood is carried from heart to rest of the body by arteries,
Smalleste arterioles and capillaries.
-->
• Blood is returned to heart by veins and venules.
the smallest
nein
-rooms
• The heart has 4 chambers.
i
• The upper chambers: are called the left and right atria. ->
• The lower chambers: are called the left and right ventricles.
->
·
--
Anatomy of the Heart
②
①
③
⑭
5.11 Circulation and Gaseous Exchange
Description of the heart
• Aorta
and pulmonary artery:
carry blood away from heart.
• Pulmonary vein and vena cava:
carry blood to the heart.
• Deoxygenated blood collected in
superior and inferior venacava
flows into right atrium.
• Oxygenated blood leaves through
Aorta.
5.11 Circulation and Gaseous Exchange
Description of the heart
• Four valves that control blood
flow:
• Mitral (bicuspid) valve
• Tricuspid valve
• Pulmonary valve
• Aortic valve
5.11 Circulation and Gaseous Exchange
Blood flows in Mammals
1.
Right atrium receives
deoxygenated blood from
superior and inferior vena cava.
2.
Deoxygenated blood flows from
right atrium into the right
ventricle through the tricuspid
valve.
3.
Then, Deoxygenated blood is
pumped into the pulmonary
artery through the pulmonary
valve to lungs.
5.11 Circulation and Gaseous Exchange
Blood flows in Mammals
4.
Oxygenated blood from lungs is
returned to the left atrium via
the pulmonary vein.
5.
Then, it enters the left ventricle
via the mitral (bicuspid) valve.
6.
Oxygenated blood exits the left
ventricle into the aorta via the
aortic valve and circulates to
body tissues.
5.11 Circulation and Gaseous Exchange
Summary of Pathway:
• Blood enters heart from superior
and inferior vena cava
1.
Right atrium
2.
Right ventricle
3.
Pulmonary arteries to the Lungs
4.
From the Lungs to Pulmonary veins
5.
Left atrium
6.
Left Ventricle
7.
Aorta to the rest of the body