Download 7-3 Cell Boundaries

7-1 Life Is Cellular
A. Early Microscopes
 In
1665, Robert Hooke used an
early compound microscope to look
at a thin slice of cork, a plant
material.
Hooke’s Drawing of Cork Cells
7-1 Life Is Cellular
Just Info.-Scientist usually use existing ideas
to further their ideas
A. The cell theory

In 1838, Matthias Schleiden
concluded that all plants were
made of cells.

In 1839, Theodor Schwann stated
that all animals were made of
cells.

In 1855, Rudolph Virchow
concluded that new cells were
created only from division of
existing cells.
7-1 Life Is Cellular
What is the cell theory?
B. The cell theory states:

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.
7-1 Life Is Cellular
Eukaryotic Cells and Prokaryotic
Cells

All animals and plants have
eukaryotic cells. These cells
have a true nucleus, and tiny
organelles that all perform
different jobs to help the cell.

Prokaryotic cells do not have a
true nucleus, and do not have
organelles. They include
bacteria, and are the most
primitive and numerous
organisms on the planet. The
oldest
prokaryotes(cyanobacteria) are
over 3.5 billion years old.
7-1 Life Is Cellular
C. Electron Microscopes

Electron microscopes reveal details
1000 times smaller than those
visible in light microscopes.

Electron microscopy can be used
to visualize only nonliving,
preserved cells and tissues.
7-2 Eukaryotic Cell Structure
D. Eukaryotic Cell Structures

Structures within a eukaryotic
cell that perform important
cellular functions are known as
organelles.

The nucleus is the control
center for the cell. The
nucleus contains nearly all the
cell's DNA.

The Cytoplasm is the portion
of the cell outside the nucleus.
Eukaryotic Cell Structures
Plant
Cell
Nucleolus
Nucleus
Smooth
endoplasmic
reticulum
Nuclear envelope
Ribosome (free)
Rough endoplasmic
reticulum
Ribosome
(attached)
Golgi
apparatus
Cell wall
Cell membrane
Chloroplast
Mitochondrion
Vacuole
Eukaryotic Cell Structures
lant
Cell
x
x
x
x
x
x
x
x
x
x
x
Eukaryotic
Cell
Structures
– Animal Cell
Nucleolus
Smooth endoplasmic
reticulum
Nucleus
Nuclear envelope
Rough
endoplasmic
reticulum
Ribosome (free)
Cell membrane
Ribosome
(attached)
Centrioles
Mitochondrion
Golgi
apparatus
Eukaryotic
Cell
Structures
– Animal Cell
J
K
A
I
B
H
C
G
D
F
E
L
Make functions easy. They make something, control something, or
Processes something.
Nucleolus- makes ribosomes
Cytoskeleton- gives support for the cell and transports information.


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




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Nucleus- contains DNA- (deoxyribonucleic acid)- controls cell
Ribosomes- make proteins
Rough Endoplasmic Reticulum-makes proteins
Smooth Endoplasmic Reticulum-makes lipids and packages proteins
Mitochondria- makes ATP for energy
Chloroplast- converts sunlight into energy and changes CO2 into
sugar-(glucose)
Golgi Apparatus- packages proteins
Vacuole- contains the cells water and removes waste
Lysosomes-breaks down toxins
Centrioles-help guide cell division
Nucleoulus –makes ribosomes
Nuclear envelope-controls what enters and leaves the nucleus
7-2 Eukaryotic Cell Structure
Nucleus
The
Nuclear
envelope
Nucleus
Chromatin
Nucleolus
Nuclear envelope
Nuclear
pores
F. The nucleus is the control center of the cell.
The nucleus contains nearly all the cell's DNA
and with it the coded instructions for making proteins and
other important molecules.
Prokaryotic cell
organism

Bacteria
7-3 Cell Boundaries

What is the main function of the
cell membrane?
F. Cell Membrane

The cell membrane regulates what
enters and leaves the cell and also
provides protection and support.

The composition of nearly all cell
membranes is a double-layered sheet
called a lipid bilayer or phospholipid
bilayer.
7-3 Cell Boundaries
What is the main function of the cell wall?
G. Cell Wall
 The main function of the cell wall is to
provide support and protection for the
cell.
 Cell walls are found in plants, algae,
fungi, and many prokaryotes.
 The cell wall lies outside the cell
membrane.
 Most cell walls are porous enough to
allow water, oxygen, carbon dioxide, and
certain other substances to pass through
easily.

7-3 Cell Boundaries
What happens during diffusion?
H. Diffusion

Particles in a solution move from an
area where they are more
concentrated to an area where they
are less concentrated.

This process is called diffusion.

When the concentration of the solute
is the same throughout a system, the
system has reached equilibrium.
7-3 Cell Boundaries
What is osmosis?
Osmosis

I.
I.
II.
III.
IV.
The diffusion of water
through a selectively
permeable membrane.
If you compare two
solutions, the more
concentrated solution is
hypertonic-more salts
or sugars (“above
strength”).
The more dilute
solution is hypotonicless salts or sugars
(“below strength”).
When concentrations of
solutions are the same
on both sides of a
membrane, the
solutions are isotonic
7-3 Cell Boundaries
J. Facilitated Diffusion
 The movement of specific
molecules across cell
membranes through protein
channels is known as
facilitated diffusion.
 Facilitated Diffusion does not
use energy directly.
 Sometimes cells move
materials in the opposite
direction from which the
materials would normally
move—that is against a
concentration difference.
 This process is known as
active transport. Energy in
the form of ATP is needed
 Passive transport is the
movement of particles
without energy
7-3 Cell Boundaries
K. Endocytosis and
Exocytosis
 Large molecules and
even solid clumps of
material taken into the cell
by means of infoldings, or
pockets, of the cell
membrane is endocytosis.
Phagocytosis-when
white blood
cells destroy foreign material.
Pinocytosis-
pinches off.
when the cell
During exocytosis, the membrane
of the vacuole surrounding the
material fuses with the cell
membrane, forcing the contents
out of the cell.
7-4 The Diversity of Cellular Life
Red blood cells transport oxygen.
7-4 The Diversity of Cellular Life
Muscle cells allow movement.
Levels of Organization
Muscle cell
L. Levels of Organization

Cells
Tissue
Smooth muscle tissue
Organ
Stomach
Organ System
Digestive system