Transcript Plant and animal cells

Plant and animal cells
Label the bits you recognise
Similarities
Plant cell
Animal cell
Differences
Plant cell
Animal cell
Plant Cells (animal cells + a bit)
Chloroplasts occur in a variety of shapes and sizes, such as
corkscrewlike ribbons or bracelet-shapes found in certain green algae. The
chloroplasts of higher plants, however, tend to be shaped somewhat like two
frisbees glued together along their edges, and when they are sliced in
median section they resemble the outline of a football. Chloroplasts may be
from 2 to 10 micrometers in diameter, and each is bounded by an envelope
consisting of two delicate unit membranes . The outer membrane apparently
is derived from endoplasmic reticulum whereas the inner membrane is
believed to have orginated from the cell membrane of a blue-green
bacterium. Within is a colorless, fluid, enzyme-containing matrix, called the
stroma. Grana (singular: granum), which are stacks of coin-shaped double
membranes called thylakoids are suspended in the stroma. The membranes
of the thylakoids contain green chlorophyll and other pigments. Theses
"coin-stacks" of grana, are vital to life as we know it on our planet today, for
it is within the thylakoids that the first steps of the all-important process of
photosynthesis occurs.
5 Minute Poster
The structure and
function of
POLYSACCHARIDES
POLYSACCHARIDES
Polysaccharides are large polymers of the monosaccharides
Unlike monosaccharides and disaccharides, polysaccharides are either
insoluble or form colloidal suspensions
The principal storage polysaccharides are STARCH AND GLYCOGEN
Starch is a polymer of alpha glucose and is, in fact, a mixture of
two different polysaccharides – AMYLOSE AND AMYLOPECTIN
AMYLOSE – long unbranched chain of glucose
units
STARCH
AMYLOPECTIN – highly branched polymer
of glucose units
AMYLOSE STRUCTURE
Amylose is formed by a series of condensation reactions that bond
alpha glucose molecules together into a long chain forming many glycosidic
bonds
CH2OH
O
H
HO
CH2OH
H
OH
H
H
OH
GLUCOSE
H
O
H
O
CH2OH
H
OH
H
H
OH
GLUCOSE
H
O
H
O
H
OH
H
H
OH
H
GLUCOSE
The amylose chain, once formed, coils into a helix
O
AMYLOSE STRUCTURE
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
THE AMYLOSE HELIX
AMYLOPECTIN STRUCTURE
Amylopectin consists of a straight chain of alpha glucose units with branch points
occurring at approximately every twelth glucose unit along the straight chain
The branch points form when carbon 6 of a glucose molecule in the straight chain
forms a glycosidic bond with carbon 1 of a glucose molecule positioned above
the chain
CH2OH
CH2OH
O
H
HO
H
OH
H
H
H
O
H
H
OH
O
H
OH
GLUCOSE
CH2OH
HO
H
OH
H
H
OH
GLUCOSE
H
1
Branch point
6 glycosidic bond
GLUCOSE
6
CH2
O
H
O
1
OH O
CH2OH
O
H
H
H
H
OH
H
H
OH
H
O
GLUCOSE
1
O
H
H
OH
H
H
OH
GLUCOSE
4 chain
H
O
AMYLOPECTIN STRUCTURE
This highly branched amylopectin molecule is wrapped around the amylose to
make up the final starch molecule
This large insoluble molecule with branch points that allow for easy access for
enzymes when breaking down the molecule, makes starch an ideal food storage
compound
GLYCOGEN
Glycogen is often referred to as animal starch
Glycogen has the same overall structure as amylopectin but
there is significantly more branching in this molecule
CH2OH
CH2OH
O
H
HO
H
OH
H
H
OH
H
H
H
OH
More of these
branch points form
H
H
OH O
Branch point
6 glycosidic bond
O
H
O
GLUCOSE
CH2OH
HO
H
OH
H
H
OH
GLUCOSE
H
6
CH2
O
H
O
1
GLUCOSE
CH2OH
O
H
1
H
OH
H
H
OH
H
O
GLUCOSE
1
O
H
H
OH
H
H
OH
GLUCOSE
4 chain
H
O
STRUCTURAL POYSACCHARIDES
Cellulose is one of the most important structural polysaccharides as it is the
major component of plant cell walls
Cellulose is a polymer of beta glucose units where each glucose molecule
is inverted with respect to its neighbour
6
CH2OH
H
4
HO
5
H
OH
3
H
O
H
O
1
OH
GLUCOSE
H
OH
H
5
2
CH2OH
2
3
4
6
OH
H
O
6
CH2 OH
GLUCOSE
1
5
1
O
4
H
OH
3
H
OH
H
O
H
3
O
1
4
OH
H
5
2
OH
GLUCOSE
2
H
1
O
6
CH2 OH
GLUCOSE
4 glycosidic bonds
The orientation of the beta glucose units places many hydroxyl (OH) groups
on each side of the molecule
Many parallel chains of beta glucose units form and each chain forms hydrogen
bonds between the OH groups of adjacent chains
STRUCTURAL POYSACCHARIDES
The bundles of parallel chains forming hydrogen bonds
with each other creates a molecule that confers rigidity
and strength to the structures of which they form a part
hydrogen bonds between parallel chains of beta glucose
The rigidity and strength of plant cell walls is a consequence
of the incorporation of cellulose into their structure
What am I?
Structure of cellulose
• Like starch, cellulose is composed of a long chain of at least
500 glucose molecules. Cellulose is thus a polysaccharide.
Several of these polysaccharide chains are arranged in
parallel arrays to form cellulose microfibrils.
• The individual polysaccharide chains are bound together in
the microfibrils by hydrogen bonds. The microfibrils, in turn,
are bundled together to form macrofibrils.
• The microfibrils of cellulose are extremely tough and
inflexible due to the presence of hydrogen bonds.
C.O.W!!
What is the most “challenging”
concept we have discussed today?
What is the middle lamella?
What is the apoplast transport system?
What is the symplast transport system?
What are plasmodesmata?
Write the question!!
1.
2.
3.
4.
5.
6.
Beta glucose
Cellulose
Middle lamella
Apoplast
Symplast
Plasmadesmata
Function of the Cellulose cell wall
Chloroplasts
Chloroplast ultrastructure
1. outer membrane
2. intermembrane space
3. inner membrane (1+2+3:
envelope)
4. stroma (aqueous fluid)
5. thylakoid lumen (inside of
thylakoid)
6. thylakoid membrane
7. granum (stack of thylakoids)
8. thylakoid (lamella)
9. starch
10. ribosome
11. plastidial DNA
12. plastoglobule (drop of lipids)
Function of a chloroplast
•
•
•
•
•
•
•
•
•
Haemogloblin
Protein structures
Oxygen dissociation
Glucose
Cellulose
Glycogen
Cells
Cell wall
Chloroplasts
•
•
•
•
•
•
•
•
Blood circulation
Capillaries
Veins
Kidneys
Liver
Arteries
Tissue fluid
Lymph