microscopes & cells california state standards: 1.a students know cells are enclosed within...
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Microscopes & Cells
California State Standards:1.a Students know cells are enclosed within semi-permeable membranes that regulate their interaction with their surroundings.
1.c. Students know how prokaryotic cells, eukaryotic cells (including those from plants and animals), and viruses differ in complexity and general structure.
1.e. Students know the role of the endoplasmic reticulum and Golgi apparatus in the secretion of proteins.
*1.j. Students know how eukaryotic cells are given shape and internal organization by a cytoskeleton or cell wall or both.
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 HookeRobert Hooke
Anton van LeeuwenhoekAnton van Leeuwenhoek
Robert BrowneRobert Browne
Cell Theory: History
• In 1838 (and 1839) German scientists, ________________ & ________________ independently came up with the “Cell Theory”
Matthias SchleidenMatthias Schleiden
Theodore SchwannTheodore 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
DNA (Nucleoid)
Ribosomes
Plasma Membrane
FlagellumFlagella
Cytoplasm
TEM of a bacterium
CiliumCilia
Differences and similarities between Prokaryotes and EukaryotesDifferences
Prokaryotes lack:
1. True nucleus
2. Membrane bound organelles
Prokaryotes are much smaller than eukaryotes (prokaryotes are about 1 – 10 m)
Similarities
Both have:
1. DNA
2. Cytoplasm
3. Ribosomes
4. Plasma Membrane
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 ______.
• What are the forms of transport across a cell membrane?
H2O produced by cell during respiration
size
Plant and Animal Cells
Comparing and Contrasting
Organelles in Eukaryotic Cells
Nucleus
• Ribosomes are made here:
• In non-dividingcells, DNA andproteins are here:
• Openings in thenuclear 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
Ribosome unit
1.Proteins made by free ribosomesfree ribosomes stay in the cell
2.Proteins made by attached ribosomesattached 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 • Metabolizes carbohydrates• Detoxifies drugs & poisons
Rough
Smooth
lipids
Golgi ApparatusER products move here in
It is the center of Manufacturing, Warehousing, Sorting and Shipping
vesicles
Mitochondria
takes place in this organelle.
It is often called the “ “ of the cell.
Cellular Respirationpowerhouse
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 that are involved in cell
division.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
Microvilli
• Projections from the cell’s surface that increase the surface area.
Microvilli
Intermediate Filaments
Microfilaments
Lysosomes
• Membrane-bound organelle that contains
enzymesdigestive
Lysosome engulfing a peroxisome and a
mitochondria
Vacuoles
• Large, central organelle
• Stores water and waste products
• In animals, it stores food
• Protists have a Contractile Vacuole
Chloroplasts
• An organelle that converts energy from the sun into chemical energy
The process is called:Photosynthesis
Cell Wall
• Found in plant and bacterial cells.
• Surrounding the , this feature does the following for plant cells:
1. Provides Support
2. Provides Protection
cell membrane