part 1 microscopes & cells microscopes and cells: history in 1663, __________ coined the term...
TRANSCRIPT
Part 1
Microscopes & Cells
Microscopes and Cells: History
• In 1663, __________ coined the term “cells”
• 10 years later, _________________ observed bacteria and protozoa
• In 1833, __________ observed and coined the term “nucleus”
Robert Hooke
Anton van Leeuwenhoek
Robert Browne
Cell Theory: History
• In 1838 (and 1839) German scientists, ________________ & ________________ independently came up with the “Cell Theory”
Matthias Schleiden
Theodore Schwann
Guten Tag, Dr. Shwann
Guten Tag, Dr. Schleiden
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…
I do believe that all cells must come from pre-
existing cells.
How big are cells?• Eukaryotic cells include
_______ & _______ cells.• Most eukaryotic cells are
between __ and ___ m.• What is the limit of the
light microscope? • Why?• What is used to see
smaller objects? __________________
plant animal
10 100
Electron Microscopes
0.2 m
Electron Microscopy
• ___________ Electron Microscopes (TEM) emit light through a thin piece of heavy metal ion stained tissue
• ________ Electron Microscopes (SEM) reflect light off of a piece of heavy metal ion stained tissue
Transmission
Scanning
Prokaryotic Cells (cells without a nucleus) for ex. bacteria
DNA (Nucleoid)
Ribosomes
Plasma Membrane
FlagellumFlagella
Cytoplasm
TEM of a bacterium
CiliumCilia
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)
Similarities
Both have:
1. DNA
2. Cytoplasm
3. Ribosomes
4. Plasma Membrane
Part 2
Eukaryotic Cells (cells with a nucleus)
Comparing and Contrasting
Organelles in Eukaryotic Cells
The Plasma Membrane
TEM of a red blood cell
Hydrophilic Region
Hydrophilic Region
Hydrophobic Region
Phospholipid
Proteins
Carbohydrate side chains
The Plasma Membrane
• It is a semi-permeable barrier that allows for the passage of certain things based upon ______, _______, and _____________.
• What are the forms of transport across a cell membrane?
H2O used by cell for Respiration
size chargessolubility in fat
• Fingerlike-projections from the cell’s surface that increase the surface area.
Microvilli
Intermediate Filaments
Microfilaments
Plasma Membrane’s Microvilli
Cell Wall• Surrounding the , this
feature does the following for plant cells:1. Provides Support
2. Provides Protection
cell membrane
Cytoplasm
• The jelly-like fluid that holds all organelles within the cell
Nucleus and nucleolus
• Ribosomes are made here:
• DNA andproteins
are found in the nucleus• Openings in the
nuclear membrane
SEM of a freeze-fractured nuclear membrane
TEM of nuclear pores
nucleolus
chromatin
Nuclear pores
Ribosomes:Function in
TEM of ribosomes
Free ribosomes
Attached ribosomes(on ER)
protein synthesis (formation)
Ribosome unit
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
Endoplasmic Reticulum
There are two types:1. ER has
ribosomes attached.• Modifies & transports
proteins
2. ER does not have ribosomes on it.
• Synthesizes • Breaks down carbohydrates• Detoxifies drugs & poisons
Rough
Smooth
lipids
Golgi ApparatusER products move here in
It is the center of Warehousing, Sorting and Shipping of Proteins
vesicles
Vesicles
Membrane-bound organelles that transports materials from the ER to the golgi
Mitochondria
takes place in this organelle.
It is often called the “ “ of the cell.
Cellular Respirationpowerhouse
Chloroplasts
• An organelle that converts energy from the sun into chemical energy
The process is called:Photosynthesis
The Cytoskeleton
• A network of fibers that extend throughout the cytoplasm
• Three types:
Microtubules
Microfilaments
Intermediate
Filaments
Cytoskeleton: Functions
1. Provides shape and support
2. Moves the cell and organelles
3. Regulates biochemical activities in cell
Organelle
Centrosome
• Microtubules grow out of this structure• In animal cells, a pair of structures called
(made of microtubules) help in celldivision.
centrioles
centrioles
centrosome
Cilia and Flagella
• Cellular projections that aide in movement
• Flagella are longer & move in a snake-like motion.
• Cilia are shorter, more numerous and move back & forth
Lysosomes
• Membrane-bound organelle that contains
enzymesdigestive
Lysosome engulfing a peroxisome and a
mitochondria
Vacuoles
• Large, central organelle in plants
• Stores water and waste products
• In animals, it stores food and is small compared plant vacuoles
• Protists have a Contractile Vacuole