Transcript Wittke 7LS Unit 5 Cells Notes

Unit 5:
Cell Structure and
Function
Overview of Cells
•Cells are the basic unit of structure
and function in living things.
•Cells perform basic functions of life:
a. Obtaining oxygen
b. Getting rid of wastes
c. Obtaining food
d. Growing
Overview of Cells
•Cells are REALLY small!
•One cm2 of your skin’s surface has
more than 100,000 cells!
First Observation of Cells
• The invention of the microscope made
the discovery of cells possible.
• Microscope- an instrument that makes
small objects larger
Development of Cell Theory
Schleiden, Schwann, and Virchowa. German Scientists that concluded
plants and animals are made of
cells.
Cell Theory
Cell Theory- widely accepted explanation
of the relationship between cells and
living things.
a. All living things are composed
of cells.
b. Cells are the basic units of
structure and function in
living things.
c. All cells are produced from
other cells.
History of the Microscope
1590- 1st compound
microscope-
1674- Leeuwenhoek’s
simple microscope.
Mag.= 266x
Zacharias & Hans
Janssen
1660- Hooke’s
compound
microscope
1886- Compound Light
Microscope- Ernst
Abbe and Carl Zeiss.
Mag.= 1000x
History of the Microscope
1933- Transmission
Electron Microscope
(TEM)- Ernst Ruska.
Mag.= 500,000x
1965- Scanning Electron
Microscope (SEM)- Mag.=
150,000x. 3D image of
specimen.
1981- Scanning
Tunneling Microscope
(STM)- Mag.=
1,000,000x
TEM photos of asbestos
SEM photo- Cholera bacteria
STM photos
Magnetic Fields
Gold molecule
Silicon Molecule
Light and Electron Microscopes
Light and Electron Microscopes
*Microscopes have 2 propertiesmagnification and resolution*
1. Magnification and lenses
a. The lenses in light microscopes
magnify an object by bending
the light that passes through
them.
Light and Electron Microscopes
b. Convex Lens- center of the lens is
thicker than the edge.
Incoming light rays
bend as they pass
through a convex
lens. When the
light hits the eye,
the eye sees the
image as larger
than it really is.
Compound Microscopes
2. Compound Microscope Magnification
a. Compound- more than one lens.
One lens is close to the eye and
the other lens is near the
specimen.
b. Total Magnification- multiply the
magnification of the 2 lenses.
Ex: First lens = 10x
Second lens= 40x
Total magnification: 10 x 40 = 400x
Compound Microscopes
3. Resolution- the sharpness of the
image. Allows us to focus on individual
parts of the object.
Compound Microscopes
4. Electron Microscopes- use a beam of
electrons instead of light to produce
a magnified image. Can capture
images of objects much smaller than
light microscopes.
Specialized Cells
1. In Multicellular organisms, cells are
specialized to perform different
functions.
Ex: Nerve cells, skin cells, blood
cells, etc.
Specialized Cells
2. Levels of Cellular Organization
a. Cell
b. Tissue- Group of similar cells that
work together (nervous, muscle,
etc.)
c. Organ- Different kinds of tissues
that work together (brain, heart,
kidney, etc.)
d. Organ System- Group of organs
that work together (respiratory,
urinary, reproductive, etc.)
Cell Parts Graphic Organizer
Cell Wall
Function
Animal or Plant?
Rigid layer around
Plant
the cell. Helps
protect and
support the cell.
Made of cellulose.
Cell Parts Graphic Organizer
Cell
Membrane
Function
Animal or Plant?
Controls what
goes in to and
out of the cell.
Both
Cell Parts Graphic Organizer
Nucleus
Function
Animal or Plant?
Cell’s control
center
Both
Cell Parts Graphic Organizer
Nuclear
Envelope
Function
Animal or Plant?
Surrounds and
protects nucleus.
Controls what
goes in to and
out of nucleus.
Both
Cell Parts Graphic Organizer
Chromatin
Function
Animal or Plant?
Inside nucleus,
contain DNA
Both
Cell Parts Graphic Organizer
Nucleolus
Function
Animal or Plant?
Inside nucleus,
where ribosomes
are made
Both
Cell Parts Graphic Organizer
Cytoplasm
Function
Animal or Plant?
Region between
the cell
membrane and
the nucleus. The
cell’s “glue.”
Both
Cell Parts Graphic Organizer
Golgi Bodies
Function
Animal or Plant?
Looks like a
flattened sac or
tube, Cell’s “mail
room.” Receive
proteins from the
ER, package
them, distribute
them to other
parts of the cell.
Both
Cell Parts Graphic Organizer
Lysosome
Function
Animal or Plant?
Small, round
structures that
contain chemicals
for breaking
down materials in
cells, Cell’s “clean
up crew.”
Both
Cell Parts Graphic Organizer
Endoplasmic
Reticulum
(ER)
Function
Animal or Plant?
Series of
passageways,
located in
cytoplasm, carry
proteins and
other materials
from one part of
the cell to
another.
Both
Cell Parts Graphic Organizer
Mitochondria
Function
Animal or Plant?
Rod-shaped,
located in
cytoplasm,
“powerhouse” of
the cell. Convert
energy in food
to a form that
cells can use.
Both
Cell Parts Graphic Organizer
Vacuole
Function
Animal or Plant?
Water-filled
sac, storage
areas for cells
Both- larger in
plant cells
Cell Parts Graphic Organizer
Chloroplast
Function
Animal or Plant?
Green, where
photosynthesis
happens.
Plants
Cell Parts Graphic Organizer
Ribosome
Function
Animal or Plant?
Located in
cytoplasm and
attached to
parts of ER.
Factories that
produce
proteins.
Both
Cell Parts Graphic Organizer
Centriole
Function
Animal or Plant?
Barrel- shaped
organelles that
help with cell
division
Animal