CELLS- STRUCTURE AND FUNCTION
Cell structure and
function
CELLS
Make up/comprise
COMPARING
Viruses,
bacteria, plant
and animal cells
modeling
relating
Organisms in a variety of
ways
Cell structure
Organelle
function & cell
function
History of living cells on
earth:
What is a cell???
 A cell is the structural and functional
unit of all living things
 Some organisms are unicellular
(bacteria, protists)
 Some organisms are multicellular
(plants, animals, fungi)
 Amount of cells in the human body=
100,000,000,000,000 (100 trillion!)
Scientist Involved in Cell Theory
 Hooke-coined the word “cell”
 von Leeuwenhoek- lens grinder; made
microscopes;
 discovered microscopic organisms in pond water
(animacules)
 Schleiden-botanist (all plants made of cells)
 Schwann-zoologist (all animals made of cells)
 Virchow-all cells produce more cells
Microscopes Used to View Cells
 Compound light
microscope- magnifies
UP TO 1500 X
 Electron Microscopes-
magnify up to 1,000,000 X
Cork
Images differ Greatly
Image of RBCs from Compound Light Microscope
(40x)
3-D image of RBCs (Scanning
Electron Microscope (SEM)
2-D image of RBCs in blood vessel
(Transmission Electron Microscope
(TEM)
Lung Cancer SEM image
Deer Tick SEM image
Bacillus
Streptococcus
Types of Cells
 EUKARYOTES
 PROKARYOTES
 Nucleus, membrane-
 No nucleus, no
bound organelles
 Protists, fungi, plants,
animals
 Humans have 200 types
of cells (60 BILLION)
membrane bound
organelles
 Archaebacteria &
Eubacteria
Features Common to Both
 cell membrane-semipermeable
 Ribosomes-sites for
protein making
 DNA
 Cytoplasm
Organelles
: COMMON TO EUKARYOTES
 Cell membrane, nucleus, nucleolus
 Cytoplasm, Ribosomes, Golgi apparatus
 Endoplasmic Reticulum, Lysosome
 mitochondria
 Plastids- (CHLOROPLASTS & LEUCOPLASTS)
PLANTS ONLY
 Cell wall- PLANTS (cellulose), FUNGI (chitin), & SOME
PROTISTS ONLY
 CENTRIOLES-ANIMALS ONLY
 Cilia=hair-like structures; Flagella = tail-like structures
A cell’s structure is directly
related to its function
FOR EXAMPLE:
1. Nerve cells have long, thin projections that
enable them to communicate with other nerve
cells.
2. Respiratory tract lining cells have cilia, which
have the job of trapping viruses and
bacteria.
3. Intestinal lining cells have projections called
microvilli, which enable them to absorb the
most nutrients possible
4. Fallopian tube lining cells:
have cilia that beat, moving fluid and
causing egg cell to move through tube
toward uterus
5. Spermatozoa
 Sperm cells have a
long, thin flagellum,
that enables them to
move through the
mucus and fluid of
the female
reproductive tract
6. Sickle Cell Anemia: genetic disorder, mutation causes
red blood cells to have a different shape- can’t do their
job efficiently!
VIRUSES CAN BE UP TO 10x SMALLER THAN
BACTERIA
Leprosy- caused by the mycobacterium leprae
SMALL POX
WHAT DO CELLS DO?
1. Take in nutrients
2. Export wastes
3. Take in gases (oxygen or carbon dioxide)
4. Release gases (oxygen or carbon dioxide)
5. Convert nutrients into energy
6. Hundreds of specialized jobs that keep you
alive!
CELL THEORY
 Proposed 200 years AFTER Hooke coined the term
cell
 All living things made of cells
 Cells are the basic unit of structure and
function in living things
 All cells come from other cells