Download The Cell

Unit 3: The Cell
Chapter 7:
Cell Structure and Function
and Function
7-2
Section Outline
7-2: Cell Structure
A) Cell Organization
B) Organelles That Store, Clean Up, and Support
C) Organelles That Build Proteins
D) Organelles That Capture and Release Energy
E) Cellular Boundaries
7-2
A -1
A) Cell Organization
1) Organelles
Many cellular structures
act as if they are
specialized organs. These
structures are known as
organelles (“little
organs.”)
•
7-2
A -2
A) Cell Organization
2) Comparing the Cell to a Factory
The eukaryotic cell is much like a living version of a modern
factory.
!
7-2
A -3
A) Cell Organization
2) Comparing the Cell to a Factory
•
The specialized machines of the factory can be
compared to the different organelles of the cell.
7-2
A -4
A) Cell Organization
2) Comparing the Cell to a Factory
•
Cells, like factories, follow instructions and make things
7-2
A -5
A) Cell Organization
3) The Nucleus
- The eukaryotic consists of two major parts:
the nucleus and the cytoplasm.
The cytoplasm is the
fluid portion of the
cell outside the
nucleus.
7-2
A -6
A) Cell Organization
3) The Nucleus
- The nucleus contains nearly all the cell’s DNA: the
instructions for making everything
7-2
A -7
A) Cell Organization
3) The Nucleus
The nucleus is surrounded by a nuclear envelope or
membranes.
•
•
nuclear pores allow
material to move into
and out of the
nucleus.
7-2
B -1
B) Organelles That Store,
Clean Up, and Support
1) Vacuoles and
Vesicles
vacuoles large, saclike, membrane-enclosed structures
•
store materials such as water, salts, proteins, and
carbohydrates.
7-2
B -2
B) Organelles That Store,
Clean Up, and Support
1) Vacuoles and
Vesicles
Plant cells have a single, large vacuole
The pressure of the central vacuole increases
their rigidity so plants can support heavy
structures such as leaves and flowers.
7-2
B -3
B) Organelles That Store,
Clean Up, and Support
1) Vacuoles and
Vesicles
Vesicles - smaller membrane-enclosed structures.
Vesicles are used to store and move materials between
cell organelles, as well as to and from the cell surface.
7-2
B -4
B) Organelles That Store,
Clean Up, and Support
2)
Lysosomes
Lysosomes - small
organelles filled with
enzymes that function
as the cell’s cleanup
crew. !
!
Lysosomes remove the
“junk” that might
clutter up the cell.
7-2
B -5
B) Organelles That Store,
Clean Up, and Support
3) The
Cytoskeleton
Cytoskeleton - network of
protein filaments and
tubes !
•
maintain shape of cell!
•
help cells move!
•
provide transport of
materials!
http://www.youtube.com/all_comments?
v=MgVPLNu_S-w
7-2
B -6
B) Organelles That Store,
Clean Up, and Support
3) The
Cytoskeleton
Microtubules - Tubes
that maintain cell shape!
!
Microfilements Threadlike structures
that make up a
framework and help cell
move
7-2
C -1
C) Organelles That Build
Proteins
Proteins are assembled on
ribosomes.
The Golgi apparatus modifies,
sorts, and packages proteins
and other materials from the
endoplasmic reticulum (ER) for
storage or release outside the
cell.
7-2
C -2
C) Organelles That Build
Proteins
1)
Ribosomes
Ribosomes are
small particles of
RNA and protein
in the cytoplasm
of all cells.
7-2
C -3
C) Organelles That Build
Proteins
1)
Ribosomes
•
Ribosomes produce
proteins by following
coded instructions that
come from DNA.
7-2
C -4
•
C) Organelles That Build
Proteins
1)
Ribosomes
Each ribosome is like a small machine in a factory, turning
out proteins on orders that come from its DNA “boss.”
http://www.youtube.com/watch?v=8dsTvBaUMvw&feature=c4overview-vl&list=PL854F3A5D92AFC121
7-2
C -5
C) Organelles That Build
2) Proteins
Endoplasmic
Riticulum
The Endoplasmic
Reticulum (ER) is
where proteins and
other materials that
are exported from the
cell are assembled
7-2
C -6
C) Organelles That Build
2) Proteins
Endoplasmic
Riticulum
The Rough ER has
ribosomes attached
so it makes proteins
The Smooth ER
holds specialized
enzymes
•
•
•
7-2
C -7
C) Organelles That Build
Proteins
3) Golgi
Apparatus
Proteins from the rough ER move into the Golgi apparatus
This appears as a stack of flattened membranes.
The proteins are bundled into tiny vesicles from the ER and
carry them to the Golgi apparatus.
7-2
D-1
•
•
•
D) Organelles That Capture
and Release Energy
Chloroplasts and Mitochondria
involved in energy conversion
contain their own DNA molecules.
chloroplasts and mitochondria descended
from independent microorganisms.
7-2
D-2
D) Organelles That Capture
and Release Energy
1) Chloroplasts
•
•
Chloroplasts
capture the energy from
sunlight and convert it into
food for plants
this is called
photosynthesis.
7-2
D-3
D) Organelles That Capture
and Release Energy
2) Mitochondria
•
•
Mitochondria
The power plants of the cell.
Convert the chemical energy stored in food into compounds
that are easier for the cell to use.
7-2
E-1
E) Cellular Boundaries
Like the roof or wall of a factory cells are surrounded by a
barrier known as the cell membrane. !
! Many cells, including most prokaryotes, also
produce a strong supporting layer around the
membrane known as a cell wall.
•
•
•
7-2
E-2
E) Cellular Boundaries
1) Cell Wall
!
Provides support and protection
Prokaryotes, plants, algae, fungi, and many prokaryotes have
cell walls. Animal cells do not have cell walls.
Cell walls lie outside the cell membrane and most are porous
(have holes)
7-2
E-3
E) Cellular Boundaries
2) Cell
Membrane
•
•
regulates what enters and leaves the cell !
protects and supports the cell.
7-2
E-4
E) Cellular Boundaries
2) Cell
Membrane
lipid bilayer - a double-layered sheet that gives cell
membranes a flexible structure and forms a strong barrier
between the cell and its surroundings.
http://www.youtube.com/watch?v=kXvLlDOgFk4
7-2
E-5
E) Cellular Boundaries
3) Fluid Mosaic
Model
The fatty acid portions of such a lipid are hydrophobic, or
“water-hating,” while the opposite end of the molecule is
hydrophilic, or “water-loving.”
7-2
E-6
E) Cellular Boundaries
3) Fluid Mosaic
Model
Most biological membranes are selectively permeable,
meaning that some substances can pass across them
and others cannot.