Download Power Point Cell Organelles

Cells
 Key Terms Pg 151, 162 all definitions will be collected
on the next exam day… They will not be allowed to be
used on the exam.
 Reading assignment




Pg 154 & 162 Prok
Pg 155 & 163 Euk
Pg 163-164 Plant Euk vs animal Euk
Pg 156-161 Euk cellular structure
The Discovery of Cells
 Microscope observations of organisms led to the discovery
of the basic characteristics common to all living things.
 Scientists first discovered cells in the 1600s using crude
microscopes.
 Observations made by scientists using more powerful
microscopes in the 1800s led to the formation of the cell
theory.
Early Compound Microscopes
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Anton van
Leeuwenhoek of
holland and
Robert Hooke
were given credit
for the invention
fo the
microscope and
the discovery of
cells.
(a)
(b)
a: Courtesy of the Armed Forces Institute of Pathology; b: © Corbis–Bettmann
The first cells seen were plant cell walls in a section of dried cork.
1-4
Cell Theory
All living things are made up of one or more cells.
2. Cells are the basic units of structure and function in
organisms
3. All cells arise from existing cells.
1.
Features of Prokaryotic and Eukaryotic Cells
Cell Features
Features of Prokaryotic Cells
 A prokaryote is an organism made of a single prokaryotic
cell.
 Prokaryotic cells do not have a nucleus or other internal
compartments. The genetic material of a prokaryotic cell is
a single loop of DNA.
 For millions of years, prokaryotes were the only organisms
on Earth.
Diversity in Cells, continued
Diversity in Prokaryotes
 Prokaryotes can vary in shape, the way they obtain and use
energy, and their ability to move.
 Many prokaryotes have a flagellum, a long, hair-like
structure that grows out of the cell and enables the cell to
move through its environment.
 Prokaryotes may also have pili, short outgrowths that allow
the cell to attach to surfaces or other cells.
Flagella On Prokaryotic Cells
B
Click to animate the image.
C
D
A
E
F
Cell Features, continued
Features of Eukaryotic Cells
 A eukaryote is an organism made up of one or more
eukaryotic cells. All multicellular organisms are made of
eukaryotic cells.
 The DNA of a eukaryotic cell is found in an internal
compartment of the cell called the nucleus.
 All eukaryotic cells have membrane-bound organelles. An
organelle is a small structure found in the cytoplasm that
carries out specific activities inside the cell.
Cell Features, continued
 Each organelle in a eukaryotic cell performs distinct
functions.
 The complex organization of eukaryotic cells enables them
to carry out more specialized functions than prokaryotic
cells.
Diversity in Cells, continued
Eukaryotic Cell Specialization
 Eukaryotic cells can vary in shape and external features.
 Depending on their function, eukaryotic cells can also vary
in their internal organelles. For example, muscle cells,
which use large amounts of energy, contain many
mitochondria.
 Animal and plant cells are two types of eukaryotic cells.
Both have many of the same organelles, but plant cells also
have chloroplasts, a large central vacuole, and a cell wall.
Comparing Prokaryotes and
Eukaryotes
Plant Cell
Eukaryotic Cells
I
C
J
A
D
B
M
L
J
E
A
G
E
F
H
G
D
C
B
F
I
H
K
Body Types
 Unicellular organisms can thrive independently or live
together in groups.
 Cells that are permanently associated but do not work
together or integrate cell activities are called colonial
organisms.
 A multicellular organism is composed of many individual,
permanently associated cells that coordinate their activities
with each other. True multicellularity occurs only in
eukaryotes.
Levels of Organization
 Plants and animals have many highly specialized cells that
are arranged into tissues, organs, and organ systems.
 A tissue is a distinct group of similar cells that perform a
common function.
 An organ is a collection of tissues that work together to
form a structure which performs a specific function.
 An organ system is composed of a group of organs that
work together to perform major body functions.
Hierarchy of Complexity
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
 Organism is composed of
organ systems
Organism
 Organ Systems composed of
organs
 Organs composed of tissues
 Tissues composed of cells
 Cells composed of organelles
Organ system
Tissue
Organ
 Organelles composed of
Cell
Macromolecule
molecules
Organelle
 Molecules composed of atoms
Atom
Molecule
Figure 1.7
1-19
Organization in Multicellular
Organisms
Nucleus
 Largest organelle
 most cells have one nucleus
 a few cells are anuclear or multinucleate
 nuclear envelope - two unit membranes surround nucleus

regulate molecular traffic through envelope
 nucleoplasm – material in nucleus
 chromatin (thread-like matter) composed of DNA and protein
 nucleoli – one or more dark masses where ribosomes are produced
3-21
Micrograph of The Nucleus
Nuclear
pores
Nucleolus
Nucleoplasm
Nuclear
envelope
(a) Interior of nucleus
2 mm
(b) Surface of nucleus
a: © Richard Chao; b: © E.G. Pollock
Figure 3.25b
Figure 3.25a
3-22
1.5 mm
Ribosomes
 Ribosomes - small granules of protein and RNA
 found in nucleoli, in cytosol, and on outer surfaces of rough
ER, and nuclear envelope
 they ‘read’ coded genetic messages (messenger RNA) and
assemble amino acids into proteins specified by the code
3-23
Endoplasmic Reticulum
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Cisternae of
rough ER
Oil droplet
(inclusion)
Nucleus
Ribosomes
of rough ER
Smooth
endoplasmic
reticulum
(a)
1 µm
(b)
1 µm
© Don Fawcett/Photo Researchers, Inc.
Figure 3.26a
3-24
Figure 3.26b
Smooth and Rough ER
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Rough endoplasmic
reticulum
Ribosomes
Smooth
endoplasmic
reticulum
3-25
Endoplasmic Reticulum
 endoplasmic reticulum - system of interconnected
channels
 Rough endoplasmic reticulum – composed of
parallel, flattened sacs covered with ribosomes
 produces the phospholipids and proteins of the plasma
membrane
 synthesizes proteins that are packaged in other organelles
or secreted from cell
3-26
Endoplasmic Reticulum
 smooth endoplasmic reticulum
 lack ribosomes
 synthesizes steroids and other lipids
 detoxifies alcohol and other drugs
 manufactures all membranes of the cell
 rough and smooth ER are functionally different parts of
the same network
3-27
Golgi Complex
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Golgi vesicles
Golgi
complex
Figure 3.27
3-28
Visuals Unlimited
600 nm
Golgi Complex
 Golgi complex - synthesize carbohydrates and put the
finishing touches on protein
 receives newly synthesized proteins from rough ER
 packages the protein into membrane-bound Golgi vesicles



some become lysosomes
some migrate to plasma membrane and fuse to it
some become secretory vesicles for later release
3-29
Lysosomes
 Lysosomes - package of enzymes bound by a single
unit membrane
 extremely variable in shape
 Functions
 Cellular digestion

Example: Proteins, worn out mitochondrion
 ‘cell suicide’ – some cells are meant to do a certain job and
then destroy themselves
3-30
Mitochondrion
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Matrix
Outer membrane
Inner membrane
Figure 3.29a,b
Mitochondrial
ribosome
Intermembrane
space
Crista
1 µm
(Left): Dr.3-31
Donald Fawcett & Dr. Porter/Visuals Unlimited
Mitochondrion
 mitochondria – organelles specialized for
synthesizing ATP
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
 surrounded by a double unit membrane
 inner membrane has folds called cristae
 spaces between cristae are called matrix
Matrix
Outer membrane
Inner membrane
Mitochondrial
ribosome
 “Powerhouses” of the cell
Intermembrane
space
Crista
 energy is extracted from organic
molecules and transferred to ATP
Figure 3.29b
3-32
Evolution of Mitochondrion
 It is a virtual certainty that mitochondria evolved from bacteria
that invaded another primitive cell, survived in the cytoplasm,
and became permanent residents
 has its own mtDNA



small circular molecule resembling bacterial DNA
replicates independently of nuclear DNA
mitochondrial DNA is almost exclusively inherited through the mother
 mutates more readily than nuclear DNA

no mechanism for DNA repair
3-33
Quiz
Identify the structures
2
1
Quiz
 3) What invention made cellular biology possible?
 4) These type of cells make up multicellular creatures?
These types of cells make up unicellular creatures?
 5) Where are ribosomes made? On what structure
would you find ribosomes attached?