Download CHAPTER 7 THE CELL

CHAPTER 7 THE CELL
THE CELL
1. Most cells are too small to be seen without a microscope
2. Anton Von Leeuwenhoek (1600’s) invented the microscope and looked at
microorganisms in water
3. Robert Hooke (1665) looked at cork and came up with the term “cell”
Van Leeuwenhoek
microscope
cork cells
4. Matthias Schleiden (1830’s) found that plants are composed of cells.
5. Theodore Schwann (1830’s) found that animals are composed of cells.
6. Rudolf Virchow (1855) stated that cells can only come from existing cells.
THE CELL THEORY
1. All things are made of cells.
 unicellular – organism is made of only one cell
 multicellular – organism is made of more than one cell
2. Cells are the basic unit of structure and function in living things.
3. New cells are produced from existing cells.
TWO TYPES OF CELLS
1. prokaryotes
 less complex
 no nucleus
 unicellular
 no membrane covered organelles
 most have a cell wall, cell membrane,
and cytoplasm
 DNA in the cytoplasm
 examples: bacteria
2. eukaryotes
 more complex
 has a nucleus
 unicellular or multicellular
 membrane covered organelles
 DNA located in nucleus
 examples: plants, animals
fungi, algae, protists
CELL STRUCTURES
1. cell wall
 found in plant cells and prokaryotes
 gives the cell structure and support
cell wall
2. cell membrane (plasma membrane) “gate keeper”
 flexible barrier around the cell that controls what enters and leaves
the cell
 composed of 2 layers of lipids
3. nucleus
 the “control center” of the cell
 contains the genetic material (DNA)
 covered by the nuclear membrane
 nucleolus – stores the material that will be used to make ribosomes in
the cytoplasm
4. cytoplasm “cyto” = cell
 all the material between the nucleus and the cell membrane
 cytoskeleton – protein filaments that provide structure and are used in
cell movement
ORGANELLES IN THE CYTOPLASM
organelle – part of a cell that has a specific function
1. ribosome
 located in cytoplasm and on rough endoplasmic reticulum
 combines amino acids together to make proteins
2. endoplasmic reticulum (ER)
 storage and delivery system for the cell
 makes lipids
 2 types
rough ER – ER that contain ribosomes
smooth ER – makes lipids
rough ER
smooth ER
3. Golgi apparatus
 modifies, processes and packages materials sent to it from the ER
Golgi apparatus
4. lysosome
 contains digestive enzymes that break down food into particles that
can be used for energy
 gets rid of waste products and worn out organelles
 protects against foreign invaders (germs)
lysosome
5. vacuole
 structure used to store water or other liquids
vacuole
6. mitochondria - “power house”
 bean shaped organelle that produces ATP
ATP is the molecule that provides energy for cell processes
ATP  ADP + energy
 highly active cells like the heart and liver have many mitochondria
mitochondria
7. chloroplast
 only found in plants and algae
 contain chlorophyll
chlorophyll – green pigment (coloring) that traps sunlight energy to
make sugar in a process called photosynthesis
chloroplast
8. cytoskeleton
“micro” = small
 microtubule - hollow protein tubes that give the cell shape and
rigidity
 microfilament - protein rods that help the cell move and change
shape
9. structures for movement
 flagella - long thin structure that uses a “whipping motion” to move
the cell
 cilia – many short hair-like structures that use a “rowing motion” to
move the cell
flagella
cilia