Download CELLS

Cells
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Life Processes
• Eating
• Drinking
• Excreting waste (urinating, defacating,
sweating, exhaling…)
• Making babies
• Respirating
• Birth, Growth, Death
First to View Cells
• In 1665, Robert
Hooke used a
microscope to
examine a thin
slice of cork
(dead plant
cells)
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First to View Cells
• Hooke called
them “CELLS”
because they
looked like the
small rooms that
monks lived in
called Cells
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Anton van Leeuwenhoek
• In 1674,
Leeuwenhoek
(Dutch microscope
maker), first to
view living
unicellular
organisms
• Leeuwenhoek used
a simple, handheld
microscope to view
pond water & teeth
scrapings
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Another important guy…
Botanist, Matthias
Schleiden, 18041881
Plants are made up
of cells!
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One more important guy
Zoologist, Theodore
Schwann 1810-1882
Concluded animals are
made of cells
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History of Cells & the
Cell Theory
Dr. Rudolph
Virchow,
1821-1902
Cells only come from
the division of other
cells
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Number of Cells
Organisms may be:
• Unicellular –
one cell
• MulticellularMade of many
Cells organized into
tissues
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THE BIG CELL THEORY
1 All living things are made of
cells.
2 Cells are the basic unit of
structure and function of living
organisms.
3 All cells can only come from
other cells.
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Cells are broken into two
main groups - Prokaryotic or
Eukaryotic
 Prokaryotes consist of bacteria &
lack a nucleus or membrane-bound
organelles
Eukaryotes include all other cells &
have a nucleus and membrane-bound
organelles (protozoans, fungi,
plants, & animals)
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Prokaryotes aka Bacteria
Contains:
•DNA
•Cell membrane
•Cell wall
•Cytoplasm
• Ribosomes (have
no membrane)
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Eukaryotic Cell
Contain 3 main cell
parts:
• Nucleus
• Cell Membrane
• Cytoplasm with
organelles
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Basic Eukaryotic Cell
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Two Main Types of
Eukaryotic Cells
Plant Cell
Animal Cell
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Eukaryotic cells have
Organelles
•
Have specific functions
•
Very small size
•
Can only be observed under a
microscope
•
Found in cytoplasm
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Similarities between plant
cells and animal cells
Both have a cell membrane
surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria,
endoplasmic reticulum, ribosomes,
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Differences between plant
cells and animal cells
Animal cells
Plant cells
No Chloroplasts
Have
chloroplasts
Irregular shape
Regular shape
No cell wall
Cell wall present
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….More Differences between
Plant Cells and Animal Cells
Animal cells
Plant cells
Vacuole small or
absent
Large central
vacuole
Glycogen as food
storage
Starch as food
storage
Nucleus at the
center
Nucleus near cell
wall
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Control Organelle
Nucleus
Controls the normal
activities of the cell
Contain the DNA in the
form of chromosomes
Bound by a
nuclear membrane
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More on the Nucleus
Nucleus
Each cell has fixed
number of
chromosomes that
carry genes
Genes control cell
characteristics
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Nucleolus
•
Cell may have 1 to 3
nucleoli
• Inside nucleus
• Disappears when cell
divides
• Makes ribosomes that
make proteins
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Smooth & Rough Endoplasmic
Reticulum
Rough ER has
ribosomes on its
surface & makes
proteins to EXPORT
out of the cell, like
saliva, insulin, etc.
Smooth ER attaches
sugars and puts
some of the
finishing touches on
the protein
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Golgi Bodies
• Stacks of flattened
sacs
• Have a shipping side &
a receiving side
• Receive & modify
proteins made by ER
• Transport vesicles
with modified proteins
pinch off the ends
Transport
vesicle
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Lysosome
• Contain digestive
enzymes
• Break down food, worn
out cell parts,
engulfed bacteria
• Programmed for cell
death (lyse & release
enzymes to break down
& recycle cell parts)
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Cell Powerhouse
Mitochondrion
(mitochondria)
Kidney bean shape
Site of Cellular
respiration
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In Animal Cells:
Mitochondria
Active cells like
muscles have more
mitochondria
Burn sugars to
produce energy ATP
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Animal Cell Organelles
• Near the nucleus
• Paired structures
• Help cell divide
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Surrounding the Cell
Cell membrane
Lies immediately
against the cell wall
in plant cells
Made of protein and
phospholipids
Selectively permeable
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Cell or Plasma Membrane
Cell membrane
• Fluid-like living
layer
• Controls the
movement of
materials into and
out of the cell
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Cytoplasm of a Cell
Cytoplasm
Jelly-like substance
enclosed by cell
membrane
Provides a medium
for chemical
reactions to take
place
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More on Cytoplasm
Cytoplasm
Contains organelles
to carry out
specific jobs
Examples:
chloroplast &
mitochondrion
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Plant Cell Organelles
Chloroplast
• Contain the green
pigment chlorophyll
• Traps sunlight to
make to make
sugars (food)
• Process called
photosynthesis
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Cell Wall
Cell wall
• Nonliving layer
• Gives structure
and shape to plant
and bacterial cells
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Plant Cell
Cell wall
• Dead layer
• Large empty
spaces present
between cellulose
fibers
• Freely permeable
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Plant Cell
Cell wall
Made of cellulose
which forms very
thin fibers
Strong and rigid
Found in plant cells
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Plant Cell
Cell wall
Protect and support
the enclosed
substances
(protoplasm)
Resist entry of
excess water into
the cell
Give shape to the cell
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Plant Cell Organelles
Vacuole
Have a large central
vacuole
Surrounded by tonoplast
Contains cell sap
Sugars, proteins,
minerals, wastes, &
pigments
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Different kinds of plant
cells
Onion Epidermal Cells
Guard Cells
root hair
Root Hair Cell
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vacuole
cytoplasm
nucleus
mitochondrion
glycogen
granule
Animal cell
No cell wall or
chloroplast
Stores glycogen
in the
cytoplasm for
food energy
cell
membrane
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Different kinds of animal
cells
white blood cell
Amoeba
red blood cell
muscle cell
cheek cells
sperm
nerve cell
Paramecium
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