Download Eukaryotic Cell Substructure

Eukaryotic Cell Substructure
Plant and Animal Cells
ANIMAL CELL
Mitochondria
Structure - composed of
modified double unit
membrane (protein, lipid)
- inner membrane infolded
to form cristae
- Function - site of cellular
respiration ie. the release
of chemical energy from
food
Glucose + Oxygen ------> Carbon Dioxide +
Water + Energy (ATP)
DNA
Inter-membrane space
Cytoskeletal structures
Cells contain elaborate
arrays of protein fibers
that serve such functions
as:
• Establishing cell shape
• Providing mechanical
strength
• Locomotion (cilia,
flagella)
• Chromosome separation
in mitosis and meiosis
• Intracellular transport of
organelles
Major components of cytoskeletal
system
• Intermediate Filaments
• Microtubules
• Actin filaments
www.cytochemistry.net/Cell-biology/filam.htm
Centrioles
• a pair of cylinder-like
structures.
• function in cell division.
• made up of nine
bundles of microtubules
• found only in animal
cells.
www.quantumconsciousness.org/.../cambrian.html
Rough and Smooth
Endoplasmic Reticulum
•Endo means within
•Plamic refers to the
cytoplasm
•Reticulum means a network.
Thus the endoplasmic
reticulum is a series of
interconnected,
intracytoplasmic, membrane
bounded sacs.
Rough endoplasmic reticulum (RER)
• appear rough due to presence of ribosomes
•involved in protein synthesis.
Smooth endoplasmic reticulum (SER)
•has no ribosomes
•The SER is involved in
•cholesterol metabolism,
•membrane synthesis, (Lipids)
•Detoxification,
•Ca++ storage along with other cellular processes.
Vesicles
Membrane bound intracellular sacs
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transport vesicles
endocytotic vesicles
exocytotic vesicles
lysosomal vesicle
secretory vesicle
adipose vesicles
Golgi Apparatus/Body
• Proteins are
transported from the
RER to the golgi
apparatus and from the
golgi apparatus to the
plasma membrane in
transport vesicles.
Lysosmes
A primary lysosome contains
many enzymes
• synthesized in the RER and
sorted in the golgi.
Peroxisomes/Micorbodies
• Organelles that contain enzymes to degrade
fatty acids and amino acids.
– A biproduct of this degradation is H2O2 hydrogen
peroxide – highly toxic to proteins
• Also contain the enzyme catalase which
destroys H2O2
• The enzymes are synthesized on the RER and
are sorted/refined into the peroxisomes in the
golgi apparatus
PLANT CELL
How Plant and Animal Cells Differ
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PLANT CELLS
Cell walls present
Plastids occur in
cytoplasm
Lysosomes not usually
evident
Centrioles present only in
cells of lower plant forms
• Large vacuoles filled with
cell sap
ANIMAL CELLS
• No cell walls
• No plastids are found
• Lysosomes occur in
cytoplasm
• Centrioles always present
• Vacuoles, if present, are
small and contractile or
temporary vesicles
Cell Wall
• Cell walls are made of
specialized sugars called
cellulose.
• Cellulose is called a
structural carbohydrate
(complex sugar)
because it is used in
protection and support.
Cell Wall
• Function
• help a plant keep its
shape
• protect the cells
• allow plants to grow to
great heights
• For smaller plants, cell
walls are slightly elastic
Plastids
• Large cytoplasmic
organelles found in the cells
of most plants
• There are three plastid
categories– Leucoplasts (white or
colorless plastids that store
starch granules) ,
– Chromoplasts (colored
plastids that store pigment
molecules like cartenoids
which store yellow and
orange pigment)
– Chloroplasts which are
essential in the
photosynthetic process
Leukoplasts
• non-pigmentous, 2x5
µm, variable shaped
plastids for storage
• 3 types: AMYLOPLASTS
(starch), ALEUROPLAST
(protein), ELAIOPLASTS
(oils)
Chromoplasts
• Chromoplast are derived
from chloroplast.
• Synthesize carotenoid
pigments such as carotene
or lycopene.
• Found in flowers, fruit, and
leaves in stress or
senescence.
• In flowers, carotenoid
pigment enables the
forming of different color,
which can attract insects
and other pollinators.
Chloroplasts
• Site of photosynthesis.
• 500,000 chloroplasts per
square millimeter of leave
surface
• Contain chlorophyll, the green
pigment that absorbs energy
from sunlight
• Sunlight captured by
chlorophyll enables carbon
dioxide from the air to unite
with water and minerals from
the soil and create food.
• Chlorophyll gives plants their
characteristic green color.
DNA
Questions
1.
2.
3.
4.
5.
6.
What are the similarities and
differences between plant and
animal cells?
Explain what is meant by the
statement "The cell is the
functional unit of life.”
_______ are known as the
'sites of intracellular digestion'.
_______ consist of enzymes,
which help in digestion.
_______ are known as the
'power-houses of the cell'.
Ribosomes are found attached
on the _______.
7.
Why don't animal cells need cell
walls?
8. The green color of leaves is due
to the presence of the _______
pigment.
9. The network of convoluted
tubules is called the _______.
10. Secretory granules are formed
by the _______ of the animal
cell.
11. _______ are known as the
'sites of protein synthesis in the
cell'.
12. Cell organelle that imparts
colour to flowers ________
Task
Use your textbook to write descriptions of the
following:
• Cytoplasm
• Cilia
• Flagella