3.1
Cell Organelles
Theory
3.2 Cell
KEY CONCEPT Cells are the Basic unit of life.
3.2
3.1 Cell
Cell Organelles
Theory
The cell theory grew out of the work of many scientists
and improvements in the microscope.
• Many scientists contributed to the cell theory.
1665: Identified
cells
Scientist
1674: Improved
microscopic
lens
1838: 1st to note
that plants are
made of cells
1839: All living
things are made
of cells
1855: All cells
come from other
cells
Draper-Fabric
Merchant
Law
M.D
M.D
3.1
Cell Organelles
Theory
3.2 Cell
The cell theory grew out of the work of many scientists
and improvements in the microscope.
• Many scientists contributed to the cell theory.
• More was learned about cells
as microscopes improved.
3.1
Cell Organelles
Theory
3.2 Cell
The cell theory grew out of the work of many scientists
and improvements in the microscope.
• Many scientists contributed to the cell theory.
• More was learned about cells
as microscopes improved.
• The cell theory is a unifying
concept of biology.
3.2 Cell Organelles Biologists’ Tools and Technology
• A microscope provides an enlarged image of an object.
– light microscopes (LM)
– scanning electron microscopes (SEM)
•
transmission electron microscopes (TEM)
stoma
3.1
Cell Organelles
Theory
3.2 Cell
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
3.1
Cell Organelles
Theory
3.2 Cell
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
– All existing cells are produced by other living cells.
3.1
Cell Organelles
Theory
3.2 Cell
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
– All existing cells are produced by other living cells.
– The cell is the most basic unit of life.
3.1
Cell Organelles
Theory
3.2 Cell
Prokaryotic (Before nucleus) cells lack a nucleus and most
internal structures of eukaryotic (True nucleus) cells.
All cells share certain characteristics.
3.1
Cell Organelles
Theory
3.2 Cell
Prokaryotic cells lack a nucleus and most internal
structures of eukaryotic cells.
• All cells share certain characteristics.
– Cells tend to be microscopic.
Bacterium
(colored SEM; magnification 8800x)
3.1
Cell Organelles
Theory
3.2 Cell
Prokaryotic cells lack a nucleus and most internal
structures of eukaryotic cells.
• All cells share certain characteristics.
– Cells tend to be microscopic.
– All cells are enclosed
cell membrane
by a membrane.
Bacterium
(colored SEM; magnification 8800x)
3.1
Cell Organelles
Theory
3.2 Cell
Prokaryotic cells lack a nucleus and most internal
structures of eukaryotic cells.
• All cells share certain characteristics.
– Cells tend to be microscopic.
– All cells are enclosed
cell membrane
by a membrane.
– All cells are filled with
cytoplasm.
cytoplasm
Bacterium
(colored SEM; magnification 8800x)
3.1
Cell Organelles
Theory
3.2 Cell
There are two cell types: eukaryotic cells and prokaryotic
cells.
3.1
Cell Organelles
Theory
3.2 Cell
There are two cell types: eukaryotic cells and prokaryotic
cells.
• Eukaryotic cells have a
nucleus.
nucleus
cell membrane
3.1
Cell Organelles
Theory
3.2 Cell
There are two cell types: eukaryotic cells and prokaryotic
cells.
• Eukaryotic cells have a
nucleus.
nucleus
• Eukaryotic cells have
membrane-bound organelles.
organelles
cell membrane
3.1
Cell Organelles
Theory
3.2 Cell
There are two cell types: eukaryotic cells and prokaryotic
cells.
• Prokaryotic cells do not
have a nucleus.
nucleus
organelles
cell membrane
3.1
Cell Organelles
Theory
3.2 Cell
There are two cell types: eukaryotic cells and prokaryotic
cells.
• Prokaryotic cells do not
have a nucleus.
nucleus
• Prokaryotic cells do not
have membrane-bound
organelles.
organelles
cell membrane
cytoplasm
3.2 Cell Organelles
KEY CONCEPT Eukaryotic cells share many similarities.
3.2 Cell Organelles
Cells have an internal structure.
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
– provides strength
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
– provides strength
– assists in cell division
3.2 Cell Organelles
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
– provides strength
– assists in cell division
– aids in cell movement
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
• The nucleus stores genetic information.
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
• The nucleus stores genetic information.
• Many processes occur in the endoplasmic reticulum.
– Also produce lipids
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
• The nucleus stores genetic information.
• Many processes occur in the endoplasmic reticulum.
• There are two types of endoplasmic reticulum.
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
• The nucleus stores genetic information.
• Many processes occur in the endoplasmic reticulum.
• There are two types of endoplasmic reticulum.
– rough endoplasmic
reticulum
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins.
• The nucleus stores genetic information.
• Many processes occur in the endoplasmic reticulum.
• There are two types of endoplasmic reticulum.
– rough endoplasmic
reticulum
– smooth endoplasmic
reticulum
-
Makes lipids, functions in breaking
down drugs and alcohol
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins. (continued)
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins. (continued)
• Ribosomes link amino acids to form proteins.
3.2 Cell Organelles
Several organelles are involved in making and
processing proteins. (continued)
• Ribosomes link amino acids to form proteins.
• Golgi Apparatus- process, sort & deliver proteins
• Vesicles are membrane-bound sacs that hold materials
until it is ready for use.
3.2 Cell Organelles
Other organelles have various functions.
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
3.2 Cell Organelles
Evidence that supports endosymbiosis of Mitochondria &
Plastids
mitochondria are the result of endocytosis of aerobic bacteria
chloroplasts are the result of endocytosis of photosynthetic
bacteria
in both cases, large anaerobic bacteria who would not
otherwise be able to exist in an aerobic environment. This
arrangement became a mutually beneficial relationship for both
cells (symbiotic).
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
• Vacuoles are fluid-filled sacs that hold materials.
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
• Vacuoles are fluid-filled sacs that hold materials.
• Lysosomes contain enzymes to digest material.
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
• Vacuoles are fluid-filled sacs that hold materials.
• Lysosomes contain enzymes to digest material.
• Centrioles are tubes found in the centrosomes.
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
• Vacuoles are fluid-filled sacs that hold materials.
• Lysosomes contain enzymes to digest material.
• Centrioles are tubes found in the
centrosomes.
– Centrioles help divide
DNA.
3.2 Cell Organelles
Other organelles have various functions.
• Mitochondria supply energy to the cell.
– Used by anthropologist to trace human ancestry
•
•
•
Vacuoles are fluid-filled sacs that hold materials.
Lysosomes contain enzymes to digest material.
Centrioles are tubes found in the centrosomes.
– Centrioles help divide
DNA.
– Centrioles form cilia and
flagella.
In what ways are lysosomes,
vacuoles and vesicles similar?
3.2 Cell Organelles
Plant cells have cell walls and chloroplasts.
3.2 Cell Organelles
Plant cells have cell walls and chloroplasts.
• A cell wall provides rigid support.
3.2 Cell Organelles
Plant cells have cell walls and chloroplasts.
• A cell wall provides rigid support.
• Chloroplasts convert solar energy to chemical energy.
Would it be accurate to say that chloroplast makes
energy for a plant cell? Explain your answer.
3.3
Cell Organelles
Membrane
3.2 Cell
KEY CONCEPT The cell membrane is a barrier that
separates a cell from the external environment.
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
cell membrane
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
– forms a boundary between inside and outside of the
cell
cell membrane
inside cell
outside cell
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
– forms a boundary between inside and outside of the
cell
– controls passage of materials
cell membrane
inside cell
outside cell
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
cell membrane
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
• There are other molecules embedded in the membrane.
cell membrane
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
• There are other molecules embedded in the membrane.
• The fluid mosaic model describes the membrane.
cell membrane
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is selectively permeable.
Some molecules can cross the membrane
while others cannot.
3.3
Cell Organelles
Membrane
3.2 Cell
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is selectively permeable.
Some molecules can cross the membrane
while others cannot.
3.3
Cell Organelles
Membrane
3.2 Cell
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
3.3
Cell Organelles
Membrane
3.2 Cell
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor
3.3
Cell Organelles
Membrane
3.2 Cell
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor
– membrane receptor
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
KEY CONCEPT Materials move across membranes
because of concentration differences.
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
Passive transport does not require energy input from a
cell.
• Molecules can move across the cell membrane
through passive transport.
• There are two types of
passive transport.
• diffusion
• osmosis
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
Diffusion and osmosis are types of passive
transport.
• Molecules diffuse down a
concentration gradient.
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
Diffusion and osmosis are types of passive
transport.
• Osmosis is the diffusion of water molecules across a
semipermeable membrane from an area of low solute
concentration to an area of high solute concentration.
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
Diffusion and osmosis are types of passive transport.
• There are three types of solutions.
• isotonic
•
hypertonic
•
hypotonic
3.4
Diffusion
and Osmosis
3.2 Cell
Organelles
Some molecules can only diffuse through transport
proteins.
• Some molecules cannot easily diffuse across the cell
membrane.
• Facilitated diffusion is
diffusion through transport
proteins.
3.2
Organelles
3.5 Cell
Active
Transport, Endocytosis, and Exocytosis
KEY CONCEPT Cells use energy to transport materials
that cannot diffuse across a membrane.
3.2
Organelles
3.5 Cell
Active
Transport, Endocytosis, and Exocytosis
Active transport requires energy input from a cell
and enables a cell to move a substance against its
concentration gradient.
• Passive transport requires no energy from the cell.
• Active transport is
powered by chemical
energy (ATP).
• Active transport occurs
through transport protein
pumps.
• Cells use active transport
to maintain homeostasis.
3.5
Transport, Endocytosis, and Exocytosis
3.2 Active
Cell Organelles
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Endocytosis is the process of
taking material into the cell.
Phagocytosis is a type of
endocytosis.
3.2
Organelles
3.5 Cell
Active
Transport, Endocytosis, and Exocytosis
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Exocytosis is the process of
expelling material from the
cell.