1. The cell theory states that all living things are made of cells, cells are the basic units of structure and function of living things, and new cells are produced from existing cells. 2. Key developments in the understanding of cells included the invention of the microscope in the 16th century which allowed the discovery of cells, and contributions from scientists in the 17th-19th centuries who observed cell structures and proposed that plants and animals are made of cells. 3. Cells are categorized as either prokaryotic or eukaryotic. Prokaryotic cells lack a nucleus and membrane-bound organelles while eukaryotic cells have a nucleus enclosed in a nuclear membrane and other membrane-bound

1. Chapter
3
Cells

2. Historical View of the Cell Theory
• As science improves, so do improvements in scientific instruments, and
improved scientific instruments lead to new discoveries
1590 – Zacharias Janssen
• Dutch lens maker, built first __________________________________________
1670’s – Anton Van Leeuwenhoek
• Dutch naturalist and lens maker, made simple microscope that could magnify
objects 270 times
• Saw bacteria, protozoa, sperm cells, red blood cells and yeast cells
1665 – Robert Hooke
• English physicist, combined two sets of lenses and produced a
_______________________________________________
• Examined a thin piece of cork, saw hollow boxes and named them
_______________________
1831 – Robert Brown
• Scottish botanist, saw central structure in plants cells, called this structure a
________________________
1838 – Matthias Schleiden
• German botanist, concluded that all plants are made of ________________
1839 – Johannes Purkinje
• Czech physiologist, studied “protoplasm”
• Stated that _________________________________________________________
________________________________________________________
_
1858 – Rudolf Virchow
• German scientist, “father of pathology”
• Concluded that _____________________________________________________
_____________________________________________________
• These discoveries, confirmed by other scientists are summarized in the cell theory
The Cell Theory
1.
2.
3.
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3. The Compound Microscope: Parts and Functions
Compound microscope - ___________________________________________________
Eyepiece or ocular lens - ___________________________________________________
Objective lens - __________________________________________________________
How to figure out magnification
• Multiply eyepiece by the objective lens
Eyepiece X objective = Magnification
10x X
10x X
10x X
Nosepiece - ______________________________________________________________
Stage - _________________________________________________________________
Stage clips - _____________________________________________________________
Body tube - ______________________________________________________________
Light source - ____________________________________________________________
Diaphragm - _____________________________________________________________
Base - __________________________________________________________________
Arm - __________________________________________________________________
Coarse focusing knob - ____________________________________________________
Fine focusing knob - ______________________________________________________
• A microscope reverses and inverts the image of an object seen under it
• Things moving under a microscope are actually moving in the opposite direction
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4. Stereomicroscope
• Binocular microscope
• Object is seen in 3-D
• Only used to see large objects
• Does not reverse or invert images
Transmission Electron Microscope
• Uses a beam of electrons instead of light rays
• 200,000x magnification
• tissues have to be sliced really thin, dry and in
a vacuum chamber
• can’t be used with living material
Scanning Electron Microscope
• provides images with 3-D quality
• can’t be used with living material
• Knowledge of cells has been increased by
manipulation and dissection of cells
Micromanipulator – used to dissect cells, can
remove nuclei
High – Speed Centrifuge
• Spin at high speeds
• Cell components sort out in different layers according to density
4

5. Microscopic Measurements
• Objects seen under the microscope are so small that they are measured in a special
unit called the ______________________________
• A micrometer is 1/1000 of a millimeter
Ex.) red blood cell = 8.5 micrometers
Bacteria = 2 micrometers
How to convert millimeters to micrometers
• Multiply by one thousand or move the decimal point 3 places to the right
Ex.) 4.56 mm =
0.0378mm =
How to convert micrometers to millimeters
• Divide by 1,000 or move the decimal point three places to the left
Ex.) A tiny worm is 2,500 micrometers long. How long is this worm in millimeters?
2,500 micrometers =
Ex.) Convert .15 micrometers to millimeters
.15 micrometers =
How to find the diameter of your field of view
• Place a transparent plastic ruler in the field of view like this
Ex.) 1.3 mm field of view
- convert to micrometers
1.3mm =
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6. Name _______________________________________ Date ______________________
Homework
1. Explain the difference between a simple microscope and a compound microscope
2. What are the three concepts of the cell theory
3. What damage can result if you focus downward while looking through the
eyepiece of a microscope? How can you prevent this?
4. If you were observing an organism in a microscope swimming up and to the right
in your field of view, what direction is it really going?
5. Compare and contrast a compound microscope and a transmission electron
microscope
6. Compare and contrast a stereomicroscope and a scanning electron microscope
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7. Prokaryotes and Eukaryotes
• cells fall into two broad categories depending on whether or not they have a
nucleus and membrane covered organelles
Eukaryotes - _____________________________________________________________
_______________________________________________________________________
_
Prokaryotes - ____________________________________________________________
_______________________________________________________________________
Prokaryotes
• generally smaller
• genetic material not in nucleus
• simple
• ex.)
Eukaryotes
• larger
• genetic material is inside of a nucleus
• complex
• ex.)
Eukaryotic Cell Structure
Plasma Membrane (Cell Membrane)
____________________________________________
____________________________________________
____________________________________________
____________________________________________
____________________________________________
• allows some materials but not others to pass
through…this is called ___________________
______________________________________
Endoplasmic Reticulum (ER)
____________________________________________
____________________________________________
____________________________________________
____________________________________________
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8. • some tubes join with the nuclear membrane
Ribosomes
______________________________________________
• attached to the walls of the ER or move freely in the
cytoplasm
Golgi Bodies (Golgi Apparatus)
____________________________________________
____________________________________________
____________________________________________
• package protein molecules in a membrane and
send the package to the cells surface
Mitochondria
____________________________________________
____________________________________________
Microtubules
_____________________________________________
_____________________________________________
Microfilaments
_____________________________________________
_____________________________________________
_____________________________________________
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9. Lysosomes
_____________________________________________
_____________________________________________
_____________________________________________
• fuses with food vacuoles to digest food into smaller
• digest old cell structures to dispose of them or even
entire cells
The Nucleus
_____________________________________________
_____________________________________________
• separated by a double layered membrane
• has pores in the membrane to permit certain
chemicals to pass
• holds the chromosomes
• chromosomes - _____________________________
_________________________________________
_________________________________________
_________________________________________
The nucleus contains two types of nucleic acids:
• DNA (deoxyribonucleic acid)
• RNA (ribonucleic acid)
Contains a smaller body called a ________________________________
• Composed of RNA
• Involved in the passage of RNA to the cytoplasm
Centrioles
_______________________________________________
_______________________________________________
Cilia and Flagella
• Outward projections from the cell membrane used for
locomotion
cilia – short, hair-like
flagella – longer, whip-like
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10. Chloroplasts
_______________________________________________
_______________________________________________
Vacuoles
_______________________________________________
_______________________________________________
• Plant cells have very large vacuoles compared to
animal cells
Cell Wall
________________________________________________
________________________________________________
• Made of cellulose
• Permits most things to pass through
Cell Wall
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11. Name ___________________________________________ Date __________________
Homework
1. Lysosomes are often referred to as “suicide sacs”. What reason can you give for
this?
2. Could a cell live without a nucleus?
3. Of what materials are chromosomes composed of? What is the function of
chromosomes?
4. Describe the difference between a typical plant cell and a typical animal cell
5. Describe the difference between the cell membrane and the cell wall
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12. Cell Boundaries
1. Cell membrane - ____________________________________________________
_________________________________________________________________
_
Outside
of cell
Carbohydrate
chains
Proteins
Cell
membrane
Inside
of cell
(cytoplasm) Protein
channel Lipid bilayer
• Made of a double layered sheet called a ______________________________
o Gives it its flexible structure
o Also contains protein molecules and carbohydrates embedded in the
bilayer
o Proteins form channels and pumps that help move material across the
membrane
o Carbohydrates act as ID cards
2. Cell Walls - ________________________________________________________
• Found in plants, algae, fungi and many prokaryotes
• Allow many molecules to pass through easily (not selectively permeable)
Diffusion Through Cell Boundaries
• One of the most important functions of the cell membrane is to regulate the
movement of dissolved molecules from one side of a membrane to the other.
Measuring concentration
Concentration - ___________________________________________________________
Ex.) What is the concentration of 12 grams of salt in 3 liters of water?
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13. Ex.) What is the concentration of 12 grams of salt in 6 liters of water?
Which is more concentrated?
• In a solution, particles move constantly. They collide with one another and tend to
spread out randomly
Diffusion - ______________________________________________________________
_______________________________________________________________________
_
Equilibrium - ____________________________________________________________
_______________________________________________________________________
_
• Because diffusion depends on random particle movements, substances diffuse
across membranes without ____________________ being used
• Even during equilibrium, particles still move, but there is no net change in
concentration
Osmosis - _______________________________________________________________
How Osmosis Works
13

14. Osmosis Terminology
Isotonic - _______________________________________________________________
_______________________________________________________________________
Hypertonic - _____________________________________________________________
_______________________________________________________________________
_
Hypotonic - _____________________________________________________________
_______________________________________________________________________
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15. Facilitated diffusion - ______________________________________________________
_______________________________________________________________________
_
ex.) glucose passing into cells
• Only go from high concentration to low
concentration
• Does not require energy
Types of Active transport
• Sometimes cells must move materials in
the opposite direction – low concentrations
to high concentrations
Active transport - _________________________________________________________
_______________________________________________________________________
_
Molecular transport - ______________________________________________________
Carrier proteins - _________________________________________________________
• Requires a lot of energy to keep working
• Moves substances against a concentration gradient
Endocytosis and Exocytosis
• Some molecules are too large to be moved by carrier proteins
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16. Endocytosis - ____________________________________________________________
_______________________________________________________________________
_
• Forms a vacuole
• Large molecules, clumps of food and even whole cells can be taken in this way
Examples of Endocytosis
Phagocytosis – extensions of cytoplasm surround a particle and package it within a food
vacuole.
• We can give this the nickname __________________________
Pinocytosis – tiny particles form along the cell membrane, fill with liquid, and pinch off
to form vacuoles within the cell
• We can give this the nickname __________________________
Exocytosis - _____________________________________________________________
_______________________________________________________________________
_
16

17. Name __________________________________________ Date ___________________
Homework
1. Describe the functions of cell membrane and cell walls
2. What happens during diffusion?
3. Describe how water moves during osmosis
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18. 4. What is the basic structure of a cell membrane
5. What is the difference between phagocytosis and pinocytosis?
6. What is the main way that active transport differs from diffusion?
7-4 The Diversity of Cellular Life
Unicellular organisms - ___________________________
• Do everything a living organism does
Ex.) yeast, protests, bacteria
Multicellular Organisms - __________________________
• Depend on communication and cooperation among specialized cells
Specialization - ________________________________________________________
____________________________________________________________________
_
Specialized Animal Cells
• Red blood cells –
• Pancreatic cells –
• Skeletal muscle –
Specialized Plant Cells
• Stomata – exchanges gases with the atmosphere
• Guard cells - ____________________________________________________
Level of Organization
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19. Tissues - ________________________________________________________________
Ex.)
Organ - _________________________________________________________________
Ex.)
Organ System - __________________________________________________________
Ex.)
• This organization creates a division of labor that makes multicellular life possible
Muscle cell Smooth muscle tissue Stomach Digestive system
Homework
1. In what kinds of organisms is cell specialization a characteristic
2. List the levels of biological organization in multicellular organisms from most
simple to most complex
3. How are unicellular organisms similar to multicellular organisms
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20. 4. Using what you know about the ways muscles move, predict which organelles
would be most common in muscle cells
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