Transcript Types of cells and organelles

Introduction to Cells
Cells are the basic units of organisms
Cells can only be observed under
microscope
Basic types of cells:
Animal Cell
Plant Cell
Bacterial Cell
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Number of Cells
Organisms may be:
• Unicellular –
composed of one cell
• Multicellularcomposed of many
cells that may
organize
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Cells May be Prokaryotic or
Eukaryotic
 Prokaryotes: include bacteria &
lack a nucleus or membrane-bound
structures called organelles
Eukaryotes: include most other
cells & have a nucleus and
membrane-bound organelles (plants,
fungi, & animals)
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Prokaryote vs Eukaryote
• Two structural types of cells are
recognized:
– Prokaryotic
– Archaea and bacteria
– Eukaryotic: plants, algae, fungi, protists, and
animals (variety)
• Comparing prokaryotic and eukaryotic
cells
– Prokaryote comes from the Greek words for
prenucleus.
– Eukaryote comes from the Greek words for
true nucleus.
Prokaryote
• Contains plasma
membrane
• Simpler internal
structure
• Absence of nucleus
• One circular
chromosome, not in a
membrane
• No membrane
enclosed organelles
• Peptidoglycan cell
walls
• Binary fission for cell
division
• Smaller
Eukaryote
• Contains plasma
membrane
• Contain nucleus
• Paired chromosomes,
in nuclear membrane
• Membrane enclosed
organelles
• Simple
(polysaccharide) cell
walls
• Cell division by
mitosis or meiosis
• Larger
Structure of Prokaryotic vs. Eukaryotic
cell
Prokaryotes – The first Cells
• Cells that lack a nucleus or
membrane-bound organelles
• Includes bacteria
• Simplest type of cell
• Single, circular chromosome
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Prokaryotes
• Nucleoid region
(center) contains
the DNA
• Surrounded by cell
membrane & cell
wall (peptidoglycan)
• Contain ribosomes
(no membrane) in
their cytoplasm to
make proteins
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Eukaryotes
• Cells that HAVE a
nucleus and membranebound organelles
• Includes protists,
fungi, plants, and
animals
• More complex type of
cells
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Differences b/w the 2 types of
cells
Eukaryotic
• Larger
• Contains membrane
bound organelles
• Contains a nucleus
Prokaryotic
• Smaller
• Does not contain
membrane bound
organelles
• No nucleus
All cells
have a:
And are grouped
into two broad
categories:
Words you can use:
•Animals
•bacteria
•chloroplasts
•Eukaryotes
•a large central vacuole
•plants
•plasma membrane
•prokaryotes
Which
are
mainly:
Which contains
unique structures
such as:
Cell
walls
Some contain
yeast and algae
Words you can use:
•Animals
•bacteria
•chloroplasts
•Eukaryotes
•a large central vacuole
•plants
•plasma membrane
•prokaryotes
All cells have a:
Plasma membrane
And are grouped into
two broad categories:
prokaryote
s
eukaryotic
Which are
mainly:
bacteria
plants
animals
Which contains
unique structures
such as:
Cell
walls
chloroplasts
Some contain
yeast and algae
A large central
vacuole
Viruses
• Non cellular
• Obligate intracellular parasites
– They must live inside another cell to survive
• Have only one type of nucleic acid
– DNA or RNA (never both)
– Single or Double stranded
• Protein coat (no plasma membrane)
• Few to no enzymes
– Takes enzymes and use host cell metabolic machinery
• No metabolic activity
• They require a host cell to exhibit the characteristics
of life.
• Virus diversity
– Different viruses have different hosts
– Only some viruses cause disease
Structure & Organelles
VOCABULARY
Organelle
Plasma Membrane
Cytoskeleton
Nucleus
Nucleolus
Golgi Apparatus
Endoplasmic
Reticulum
• Chloroplast
• Mitochondria
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Lysosome
Vacuole
Vesicle
Cell wall
Ribosome
Cytosol
Cytoplasm
Organelles
• Very small (Microscopic) “little
organs” that carry out specific
functions within each cell
• Perform various functions for a
cell
• Found in the cytoplasm
• May or may not be membranebound
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Eukaryotic: Animal Cell
Eukaryotic: Plant Cell
Prokaryotic Cell
Plasma Membrane (AKA
cell membrane
• Function: A
flexible boundary
that controls the
movement of
substances in and
out of the cell.
• Key word:
Selective
permeability.
• Cell Type: All cells
• Analogy:
__________
Cell Membrane in Plants
Cell membrane
• Lies immediately
against the cell
wall in plant cells
• Pushes out against
the cell wall to
maintain cell shape
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Cell Wall
Cell wall
• Nonliving layer
• Found in plants, fungi, &
bacteria
• Made of cellulose in
plants
• Made of peptidoglycan in
bacteria
• Made of chitin in Fungi
• Cell Type: Plants
• Analogy:____________
_________________
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Cell Wall
• Supports and
protects cell
• Found outside of the
cell membrane
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More on Cytoplasm
cytoplasm
• Contains organelles to
carry out specific jobs
• Collective term for
cytosol plus the
organelles suspended
within the cytosol
• Found in ALL cells
• Analogy:__________
____________
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Cytosol
• The fluid
surrounding the
cytoplasm’s
organelles, internal
membranes, and
cytoskeleton fibers
• Analogy:_________
______________
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Cytoskeleton
• Helps cell maintain cell
shape and supporting
structure
• Also help move organelles
around
• Made of proteins
• Microfilaments are
threadlike & made of ACTIN
• Microtubules are tubelike &
made of TUBULIN
• Analogy:________________
____________
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Cellular Support
• Cytoskeleton is made of
microtubules thin, hollow
cylinders made of protein,
& microfilamentsthin solid
protein fibers
Cytoskeleton
MICROTUBULES
MICROFILAMENTS
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Nucleus
• Function: The
nucleus contains
the cells DNA,
stores
information used
to make proteins
– For cell growth,
function &
reproduction.
• Key Word: Control
Center
• Cell Type: All
Eukaryotic Cells
• Analogy:
____________
Nucleolus
• Inside nucleus
• Cell may have 1 to
3 nucleoli
• Disappears when
cell divides
• Makes ribosomes
that make proteins
• Analogy:________
____________
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Endoplasmic Reticulum - ER
• Network of hollow membrane tubules
• Connects to nuclear envelope & cell
membrane
• Functions in Synthesis of cell products &
Transport
Analogy?_______
_____________
_____________
Two kinds ofcopyright
ER ---ROUGH
& SMOOTH
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Rough Endoplasmic Reticulum (Rough
ER)
• Has ribosomes
on its surface
• Makes
membrane
proteins and
proteins for
EXPORT out of
cell
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Smooth Endoplasmic Reticulum
• Smooth ER lacks
ribosomes on its
surface
• Is attached to the
ends of rough ER
• Makes cell products
that are USED
INSIDE the cell
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Functions of the Smooth ER
• Makes membrane
lipids (steroids)
• Regulates calcium
(muscle cells)
• Destroys toxic
substances
(Liver)
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Ribosomes
• “Protein
factories” for cell
• Small particles of RNA and protein found
throughout the cytoplasm. Produce proteins by
following coded instructions that come from the
nucleus.
• Join amino acids to make proteins
• Process called protein synthesis
• Analogy:________

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Golgi Apparatus
• Function: It’s a
flattened stack of
membranes that
modifies, sorts &
packages proteins
into sacs.
• Key Word: Packing
& Sorting
• Cell Type: All
Eukaryotic Cells
• Analogy:
____________
Golgi Bodies
Look like a stack of pancakes
Modify, sort, & package
molecules from ER
for storage OR
transport out of cell
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Golgi
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Vesicles
-small saclike
organelles that
store and
transport
materials around
the inside of cells
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Chloroplasts
• Function: Capture
light energy &
convert it into
chemical energy
through
photosynthesis.
• Key Word:
Producer of energy
• Cell Type: Euk.
Plant cell
• Analogy:
____________
Vacuoles
• Fluid filled
sacks for
storage
• Small or absent
in animal cells
• Plant cells have
a large Central
Vacuole
• No vacuoles in
bacterial cells
• Analogy:_____
__________
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Vacuoles
• In plants, they store
Cell Sap
• Includes storage of
sugars, proteins,
minerals, lipids,
wastes, salts, water,
and enzymes
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Mitochondria
• Function: It
converts fuel
particles (mainly
sugar) into usable
energy.
• Key Word:
Powerhouse
• Cell Type: All
Eukaryotic Cells
• Analogy:
____________
MITOCHONDRIA CONT
Surrounded by a DOUBLE
membrane
Has its own DNA
Folded inner membrane
called CRISTAE
(increases surface area
for more chemical
Reactions)
Interior called MATRIX
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Interesting Fact --• Mitochondria
Come from
cytoplasm in the
EGG cell during
fertilization
Therefore …
• You inherit your
mitochondria
from your
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Lysosomes
• Function:
Processes
enzymes that
digest excess or
worn out
organelles,
wastes.
• Key Word: Gets
rid of waste
• Cell Type: Euk.
Animal Cells
• Analogy:
____________
Similarities between plant
cells and animal cells
Both have a cell membrane
surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria
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Differences between plant
cells and animal cells
Animal cells
Plant cells
Relatively
smaller in size
Relatively larger
in size
Irregular shape
Regular shape
No cell wall
Cell wall present
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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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Cell Movement with Cilia &
Flagella
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Cilia & Flagella
• Cilia short,
numerous,
hair-like
projections
that move in
a wavelike
motion
• Flagella
larger
projections
that move w/
a whip-like
motion
Cilia & Flagella
• Cilia are
shorter and
more numerous
on cells
• Flagella are
longer and
fewer (usually
1-3) on cells
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Cilia Moving Away Dust Particles from
the Lungs
Respiratory System
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Cell Size
Question:
Are the cells in an elephant
bigger, smaller, or about the
same size as those in a
mouse?
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Cell Size
Question:
Are the cells in an elephant
bigger, smaller, or about the
same size as those in a mouse?
About the same size, but …
The elephant has MANY MORE cells
than a mouse!
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