Download Cells 09 - Biology R: 4(A,C)

What do these have in common?
From Simple to More Complex
 Many multicellular organisms have structures
called organs that have a specific function and work
with other organs. Working together, these organs
carry out the life processes of the entire organism.
 1. Some activities cannot be performed by only one person, but
need a team of people. What type of activity requires a team of
people to work together in order to complete a task?
 2. What do you think are some characteristics of a successful team?
 3. How is a multicellular organism similar to a successful team?
Go to
Section:
Levels of Organization
Levels of Organization
 Cell: specialized to obtain food & oxygen, and carry out
specific functions
 Tissue: a group of similar cells that perform a particular
function
 Four types of tissue in living things: epithelial (skin), muscle,
nerve, & connective (bone, blood, cartilage & lymph)
 Organs: many tissues working together to perform a
function (ex. Muscle = muscle tissue, nerve tissue &
connective tissue)
 Organ systems: group of organs working together to
perform a specific task (ex. Digestive system, nervous
system, & circulatory system)
Section 7- 4
Levels of Organization
Muscle cell
Go to
Section:
Smooth muscle tissue
Stomach
Digestive system
Cells
 Cells = basic unit of life
 Can be many different sizes
(always very small)
 Discovered by Anton Van Leeuwenhoek
(1600s)
History
 1665 – Robert Hooke published drawings of cork viewed
through a microscope
 1674 – Anton van Leeuwenhoek observed tiny living
organisms in drops of pond water
 1838 – Matthias Schleiden concludes that plants are made
up of cells.
 1830 – Theodor Schwann concludes that all animals are
made up of cells.
 1855 – Rudolph Virchow proposes that all cells come from
existing cells by cellular reproduction
The Cell Theory
 All living things are composed of cells.
 Cells are the basic units of structure and
function in living things.
 New cells are produced from existing cells.
Exceptions to the Cell Theory
• Within the cell there are structures that can
reproduce themselves
– scientists believe that mitochondria and
chloroplasts evolved from more primitive life
forms.
• Not all parts of living things are composed of “normal”
cells.
– Ex. Skeletal muscle contains many nuclei within
one cell.
• Viruses are often thought of as living cells, but they
can’t reproduce on their own and they do not contain
any organelles.
Interest Grabber
Section 7-1
Are All Cells Alike?
 All living things are made up of cells. Some organisms are composed of
only one cell. Other organisms are made up of many cells.
 1. What are the advantages of a one-celled organism?
 2. What are the advantages of an organism that is made up of

many cells?
Go to
Section:
Unicellular vs. Multicellular
 Unicellular (one-celled) organism
 Multicellular (many-celled) organisms
Multicellular Organisms
 The cells in a multicellular organism are
interdependent (can not live on their own)
(they depend on each other like players on a team)
 Cell specialization = each type of specialized cell
performs separate roles or functions within the
organism, has a different number of each organelle
depending on function
 Ex: red blood cells, nerve cells, muscle cells, pancreatic
cells – have enormous amounts of organelles involved
in their functions
Plant vs. Animal Cell
Unicellular Organisms
 One-celled organism is able to function despite
lacking the levels of organization present in more
complex organisms.
 The structures present in some single-celled organisms
act in a manner similar to the tissues and systems
found in multicellular organisms, thus enabling them
to perform all of the life processes needed to maintain
homeostasis.
 They do everything you would expect a living thing to
do.
 Ex: yeast
Unicellular organisms
Paramecium
Euglena
Prokaryotes vs. Eukaryotes
Cells
Prokaryotes
No nucleus
Smaller and simpler
Have cell membranes
Have cytoplasm
Ex. Bacteria
Eukaryotes
Have a Nucleus
Larger and complex
Have organelles
Single or Multi- celled
Ex. Plants, animals & fungi
Prokaryotic and Eukaryotic Cells
Section 7-1
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Nucleus
Eukaryotic Cell
Organelles
Go to
Section:
Section 7-2
Division of Labor
 A cell is made up of many parts with
different functions that work together.
Similarly, the parts of a city work together to
carry out different functions.
 1. What are some of the different parts of a city? What are the
functions of these city parts?
 2. How do the functions of these city parts correspond to
the functions of certain cell parts?
Go to
Section:
Structures
 Cells have particular structures that perform specific
jobs. These structures perform the actual work of the
cell. Just as systems are coordinated and work together,
cell parts must also be coordinated and work together.
 These structures are called organelles.
Cell Organelles
• What is an organelle?
– They are specialized microscopic
structures within cells
– They are contained within the cytoplasm
• exception- nucleolus is contained within the nucleus
– They have characteristic structures and
functions.
Section 7-2
Cell Structures
 A.
 B.
 C.
1.
2.
3.
 D.
 E.
Go to
Section:
1.
2.
3.
4.
5.
6.
7.
Cell Wall
Cell Membrane
Nucleus
Chromatin and Chromosomes
Nucleolus
Nuclear Envelope
Cytoskeleton
Organelles in the Cytoplasm
Ribosomes
Endoplasmic Reticulum
Golgi Apparatus
Lysosomes
Vacuoles
Chloroplasts
Mitochondria
STRUCTURE OF ORGANELLES
 TWO TYPES:
• MEMBRANE BOUND ORGANELLES
• CELL PARTS NOT SURROUNDED BY A
MEMBRANE
Cell parts not bound by a
membrane
 1. Cell wall
2. Cell membrane
3. Cytoplasm
4. Cytoskeleton
Cell Wall
 Strong layer on the outside of
plant, algae, fungi and many
prokaryotic cells (not in
animal cells)
 Support and protect the cell
 Allow water, oxygen, carbon
dioxide and other substances
to pass through
 Made from fibers of
carbohydrates and
proteins, for example,
cellulose (tough
carbohydrate fiber in plant
cell walls) found in paper
Cell Membrane
 Thin, flexible barrier around




cells (inside cell wall on plant
cells)
Provides protections and
support
Helps maintain the chemical
balance between materials
inside and outside the cell by
removing wastes from the cell
Selectively permeable = allows
only certain material in or out of
the cell
Made up of a lipid bilayer with
some proteins scattered
throughout
Cytoplasm
 The gel-like material
inside the cell (not
including the nucleus
and organelles)
 Transports materials
throughout the cell
 Holds organelles
 Constantly moving or
flowing
Cytoskeleton
 Helps support some cells
 Network of protein filaments
that helps keep the cell’s shape
 Involved in many forms of cell
movement
 Microtubules – hollow tubes of
protein that serve as “tracks” for
moving organelles, form
centrioles in animal cells to help
separate chromosomes during
cell division, form cilia or
flagella to move
 Microfilaments – long, thinner
fibers functioning in support
and movement within the cell
Section 7-2
Cytoskeleton
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Go to
Section:
Michondrion
Membrane Bound Organelles
 Specialized structures that perform cellular functions
1. Nucleus
2. Ribosomes
3. Endoplasmic Reticulum
4. Golgi Apparatus
5. Lysosomes
6. Vacuoles
7. Chloroplasts
8. Mitochondria
Nucleus
 Large structure that contains the cell’s
genetic material or hereditary
information (DNA) & instructions
for making proteins (RNA)
 Controls the cell’s activities
 Chromatin – granular material visible
with nucleus made up of DNA bound
to protein
 Chromosomes – formed by chromatin
during cellular reproduction (genetic
information to be passed on to the
next generation)
 Nucleolus – small, dense region
within the nucleus where ribosome
assembly begins
 Nuclear Envelope – double membrane
around the nucleus with nuclear pores
to allow material to move through
(including RNA)
Ribosomes
 Made of RNA and protein
 Build proteins on ribosome from proteins
and RNA (coded instructions from the
nucleus)
Endoplasmic Reticulum
 Internal membrane making
parts of the cell membrane and
modifying proteins
 Rough ER – with ribosomes to
make proteins, has a rough
appearance through the electron
microscope

As each protein is made it crosses
the ER membrane and enters the
ER for chemical modification
 Smooth ER – lacks ribosomes
and appear smooth under the
electron microscope

Contain enzymes to perform
specialized tasks such as making
lipids and breaking down toxic
substances.
Golgi Apparatus
 Stacked membranes with enzymes to package
proteins by attaching carbohydrates and lipids
Lysosomes
 Small spheres filled
with enzymes to
break down lipids,
carbohydrates, and
proteins from food
into smaller particles
to be used by the rest
of the cell, as well as
worn-out organelles
and wastes
Vacuoles
 Sac-like structure to
store materials
including water, salts,
proteins, and
carbohydrates
 Plant cells contain a large
central vacuole with
enough pressure to make
the cell rigid
 Animal cells contain
smaller vesicles that
transport substances
within the cell
MEMBRANE FLOW
Proteins are made
at ribosomes
Proteins sent through
ER to Golgi
nucleus
GOLGI
Secretory vessicles remove
protein from cell by
exocytosis.
Chloroplasts
 Use energy from sunlight
with carbon dioxide and
water to make food
(carbohydrates) and
oxygen through
photosynthesis in plant
cells and some other cells
(not in animal/fungi cells)
 Double envelop membrane
 contain the green pigment
chlorophyll
 Contain some of its own
genetic information (DNA)
Mitochondria
 Use food to make
energy (ATP) for
growth, development,
and movement
 Double envelop
membrane
 Contain some of its
own genetic
information (DNA)
ENDOSYMBIOSIS
LIVING TOGETHER
 SINCE CHLOROPLASTS AND
MITOCHONDRIA HAVE
THEIR OWN DNA, THEY
MIGHT HAVE ORIGINATED
AS FREE LIVING
ORGANISMS.
 CHLOROPLAST AND
MITOCHONDRIA DO NOT
HAVE ENOUGH DNA TO
LIVE ALONE, BUT MAY
HAVE AT ONE POINT IN
TIME A LONG TIME AGO.
 THEORY OF CHLOROPLAST
ENDOSYMBIOSIS:
 THEY GET CAUGHT INSIDE A
HETEROTROPH (CELLS THAT
DO NOT MAKE FOOD) AND
THEY STAY THERE.
 CHLOROPLAST PROVIDES
FOOD AND CELL PROVIDES
PROTECTION
 OVER TIME CHLOROPLASTS
LOSE THE ABILITY TO LIVE
INDEPENDENTLY.
Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrian
Rough endoplasmic reticulum
Plant Cell
Go to
Section:
Section 7-2
Nucleolus
Nucleus
Ribosome
(attached)
Nuclear
envelope
Mitochondrian
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus
Animal Cell
Go to
Section:
Ribosome
(free)
Cell
Membrane
Onion Cells
Cheek Cells
What did you observe in the onion cells and cheek cells?
Section 7-2
Prokaryotes
Eukaryotes
Cell membrane
Ribosomes
Cell wall
Cytoplasm
Animal Cells
Lysosomes
Go to
Section:
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
What kind of cell is it?
Prokaryote/Eukaryote & Animal (like)/Plant (like) & Unicellular/Multicellular
What would happen if
something didn’t work right?
 A.
 B.
 C.
1.
2.
3.
 D.
 E.
1.
2.
3.
4.
5.
6.
7.
Cell Wall
Cell Membrane
Nucleus
Chromatin and Chromosomes
Nucleolus
Nuclear Envelope
Cytoskeleton
Organelles in the Cytoplasm
Ribosomes
Endoplasmic Reticulum
Golgi Apparatus
Lysosomes
Vacuoles
Chloroplasts
Mitochondria