Download in eukaryotic cells

Microscopes & Cells
Don’t copy down this slide – just listen
Microscopes and Cells: History
• In 1663, Robert
__________
Hooke
coined the term “cells”
• 10 years later,
Anton
van Leeuwenhoek
_________________
observed bacteria and
protozoa
Browne
• In 1833, Robert
__________
observed and coined
the term “nucleus”
Guten Tag, Dr. Shwann
Cell Theory: History
Guten Tag, Dr. Schleiden
• In 1838 (and 1839)
German scientists,
Matthias Schleiden
________________
&
Theodore Schwann
________________
independently came
up with the
“Cell Theory”
It appears we have come
up with a very similar
theory…
What shall we call this
theory?
Cell Theory
1. All living things are composed of one or
more cells.
2. Cells are organisms' basic units of
structure and function.
3. Cells form by free-cell formation, similar
to the formation of crystals (spontaneous
generation).
• In 1855, German physician Rudolph
Virchow discovered that…
all cells must
come from
pre-existing
cells.
Please add the above as point #4 to the
cell theory
How big are cells?
• Eukaryotic cells include
plant
animal cells.
_______
& _______
• Most eukaryotic cells are
between 10
__ and ___
100 m.
• What is the limit of the
light microscope? 0.2 m
• Why? It is limited to the
visible light spectrum
• What is used to see
smaller objects?
__________________
Electron Microscopes
Electron Microscopy
• ___________
Transmission Electron
Microscopes (TEM)
emit light through a thin
piece of heavy metal
ion stained tissue
Scanning Electron
• ________
Microscopes (SEM)
reflect light off of a
piece of heavy metal
ion stained tissue
Prokaryotic Cells (cells without a
nucleus) for ex. bacteria
Label this diagram in your handout
DNA (Nucleoid)
Ribosomes
Plasma Membrane
Cytoplasm
Cilia
Cilium
Flagella
Flagellum
TEM of a bacterium
Eukaryotic Cells
(cells with a nucleus)
Plant cell
Animal cell
Eukaryotic cells
include both plants
and animal cells
Differences and similarities between
Prokaryotes and Eukaryotes
Differences
Prokaryotes lack:
1.True nucleus
2.Membrane bound
organelles
Prokaryotes are much
smaller than eukaryotes
(prokaryotes are
~1 – 10 m and eukaryotes
are 10 – 100 m )
Similarities
Both have:
1. DNA
2. Cytoplasm
3. Ribosomes
4. Plasma Membrane
The Plasma Membrane
(in all cells)
• It is a semi-permeable
barrier that allows for
the passage of some
things based upon
charges and
size
______,
_______,
solubility in fat
_____________.
Plasma Membrane’s
Microvilli
• Fingerlike-projections from
the cell’s membrane that
increase the surface area.
Cell Wall
(in plant cells and prokaryotic cells)
•
Surrounding the cell membrane , this
1. provides support
2. protects
plant cells and
prokaryotes
Cytoplasm
(in all cells)
• The jelly-like fluid that holds all organelles
within the cell
Cilia and Flagella
(in all cells)
• Hair-like projections that
aide in movement
• Cilia are shorter,
more numerous and
move back & forth
• Flagella are longer &
move in a snake-like
motion.
Nucleus and
nucleolus
SEM of a freeze-fractured
nuclear membrane
(in eukaryotic cells)
• _________make
Nucleolus
ribosomes
here:
• Nucleus holds
DNA wrapped
around proteins that
form chromatin
________
Nuclear pores
• ____________,
allow things to
pass into and out
of the nucleus
TEM of nuclear pores
Ribosomes: (in all cells)
Function in protein synthesis (formation)
1. Proteins made by free ribosomes stay in the cell
2. Proteins made by attached ribosomes are shipped
out of the cell or sent to the membrane
Free ribosomes
Attached ribosomes
(on ER)
TEM of ribosomes
Ribosome unit
Endoplasmic Reticulum
(in eukaryotic cells)
There are two types:
1. Rough ER has ribosomes
attached.
•
Modifies & transports
proteins
2. Smooth ER does not have
ribosomes on it.
•
•
•
Makes lipids (fat)
Breaks down carbohydrates
Detoxifies drugs & poisons
Vesicles (in eukaryotic cells)
Organelles that
transport
proteins from
the ER to the
golgi and
eventually to
the plasma
membrane
Golgi Apparatus (in eukaryotic cells)
Vesicles carrying protein from the ER move here.
_______
It sorts, packages, and ships
these proteins outside the
cell or to the membrane.
Mitochondria (in eukaryotic cells)
Cellular Respiration takes place here.
powerhouse of the cell because it creates
It is the “____________”
energy using oxygen.
Chloroplasts (in plant cells)
• This changes energy from the
sun into chemical energy (sugar)
in a process is called
photosynthesis
The Cytoskeleton
(in all cells)
3 types: microtubules,
microfilaments, and intermediate
filaments
The Cytoskeleton
(in all cells)
1. Provides shape and support (skeletal)
Organelle
2. Moves the
organelles within the
cell and helps move
flagella/cilia
Centrosome (in eukaryotic cells) and
Centrioles (in animal cells only)
• Centrosomes make microtubules (cytoskeleton).
• In animal cells, a pair of structures called
centrioles (made of microtubules) help
in cell division.
Centrosome
(halo)
centrioles
Lysosomes (in animal cells)
• Special vacuole in animal
digestive
cells with _________
enzymes that help cleanup the cell
Lysosome engulfing a
worn-out organelle
Vacuoles (in eukaryotic cells)
• Large, central
organelle in plants
• Stores water and
waste products
• In animals, it stores
food and is small in
size compared to
plant vacuoles