CHAPTER 4
4.1 History of Cell Biology
OBJECTIVES:
– Name scientists who first observed living and
non living cells.
– Summarize research that led to cell theory.
– State 3 principles of Cell Theory
– Explain why cells are basic units of life
Discovery of Cells
A. Hooke
A. Discovered cells in
cork
B. 1st to observe dead
cells
B. Leeuwenhook
A. First to observe
living cells
B. Described first cells
as animulcules
Cell Theory
A. Cell Theory has 3 parts
A. All living organisms are composed of one or
more cells.
B. Cells are the basic units of structure.
C. Cells come only from the reproduction of
existing cells.
Cellular Basis of Life
A. All living things
A. Have cells
B. Obtain energy
C. Perform chemical reactions
D. Change with time
E. Respond to the environment
F. reproduce
4.2: Introduction to cells
Objectives:
– Describe 3 basic parts
– Compare prokaryotic and eukaryotic cells
– Analyze relationship between cells, tissues,
organs, organ systems, and organisms
Cell Diversity
A. Cell shape reflects the different functions
of the cell.
B. Cells not only differ in the shape but also
the size.
Two basic types of cells
A. Prokaryotic Cells
– Do NOT have a
nucleus
– Bacteria
B. Eukaryotic Cells
Has a nucleus
Has organelles
Has
Nucleus
Ribosomes
and DNA
No Nuclear
Membrane
Cell Organelles
Animal Cell
Plant Cell
Cell Organelles
A. Plasma Membrane
A. Covers the cell and acts as a barrier
between the inside and outside
B. Cytoplasm
A. Fluid inside the cell
C. Nucleus
A. Control center of cell
B. Controls most functions of the cell
Cell Organelles
D. Nucleolus
A. Site of DNA (genetic material)
E. Ribosomes
A. Made of protein
B. Direct construction of protein
F. Mitochondria
A. Powerhouse of the cell
B. Transfers energy
Cell Organelles
G. Rough endoplasmic reticulum
A. System of flattened sacs
B. covered with ribosomes
C. produces phospholipids and proteins
D. transport system
H. Smooth endoplasmic reticulum
A. builds lipids (cholestrol)
B. Abundant in liver and kidneys
C. Detox body
Cell Organelles
I. Golgi Apparatus
A. Packages materials throughout the cell
J.
Lysosomes
A.
Contain enzymes
Cytoskeleton
K.
A.
Microtubules
A.
B.
Provide structure
Microfilaments
A.
Contribute to cell movement
Cell Organelles
L. Cilia
A. many hairlike structures used for
movement
M. Flagella
A. Tail like organelle
B. Assists in movement
C. Tail on human sperm cells
N. Centrioles
A. Organize cytoskeleton for cell division
Cell Organelles
N. Cell Wall
A. Outside plasma membrane
B. Found only in PLANT cells
C. Provides structure
O. Vacuole
A. Storage sac
P. Chloroplasts
A. Used in photosynthesis (green)
Cell WALL
Cell
MEMBRANE
Nucleus: control center for the cell
4. Ribosomes: grain like bodies
on the ER & in the cytoplasm
5.Endoplasmic Reticulum: (called ER) carry
proteins and materials within the cell
6. Golgi Body: receives and packages
proteins from ER and distributes
around cell and body (mailroom)
7. Cytoplasm: clear gelatinous fluid
inside a cell
8. Vacuoles: storage area of the cell
Plant has one large vacuole
Stores food, waste, & enzymes
9. Mitochondria = powerhouse of the cell; where
cell energy comes from.
10. Chloroplasts: ONLY IN PLANTS
captures sunlight and produces food
for the cell
11. Flagella = used for movement
12. Cilia = used for movement; tiny
hair-like structures; found on
cells that need to move mucus
COMPARE and CONTRAST Plant and
Animal Cells
Animal
Cytoskeleton
Plant
Cell Wall
Nucleus
Cell Membrane
Chloroplasts
Large Vacuole
Importance of Cell Surface Area
What is surface area?
– The amount of surface for a cell
Why is surface area important?
– When the volume of the cell increases, the
surface area increases
– S.A. limits cell growth because if the cell
becomes to large it will not be able to take in
enough food and get rid of enough waste