Transcript Cell Organization

CHAPTER 2
cells P. 38 - 44
EARLY DISCOVERIES
Anton
Van Leeuwenhoek
- made microscopes.
- saw “critters” in a
drop of water never
seen before.
Robert Hooke
- first to see cells in
slices of cork
- ‘named’ cells.
Led to others studying cells.
Matthias Schleiden
- studied every part of
plants.
- concluded all plant parts
were made of cells.
Theodor Schwann
- studied animals.
- concluded that all
animals were made of
cells.
Rudolph Virchow
- new cells come
from other living
cells.
These scientists’ work led to the
Cell Theory.
Cell theory
1.
2.
3.
All organisms are made of
cells.
Cells are the basic unit of
structure and function in all
organisms.
All cells come from other
cells.
Read p. 38 - middle p. 42.
STRUCTURE OF CELLS
(p. 38)
Scientists discovered there
were parts inside the cell.
A) Cell Membrane
Like the protective skin of the cell
- the outer covering.
- controls what goes in and out.
 Food , water, oxygen enter - Wastes
leave.
 Selectively permeable: controls what
enters and leaves

CELL MEMBRANE
B) Nucleus
the ‘control center’.
B1) nuclear membrane
-controls what
goes in and out of
the nucleus.
-
Contains chromosomes:
- structures that hold
hereditary material to
determines what you look
like.
- made of DNA.
C) Cytoplasm
Found inside the cell membrane outside
the nucleus.
 Gel - like substance: mostly water.
 Contains small structures called organelles
-all have a “job” inside the cell.

CYTOPLASM
Cell Organelles


Cells work 24 hours a day, 7 days a week
Cell Organelle: working parts of the cell.
Cell Organelles
1. Mitochondria
 Powerhouse of cell
 Food broken down and
energy is released.
 Which cells might have
lots of mitochondria?
2. Endoplasmic Reticulum (E.R.)
 Folded membrane
 Like conveyer belts in the factory.
(or a highway)

Transports materials throughout
the cell.
3. Ribosomes
 Most numerous organelle in the cell
 Some attached to E.R.
 Produces protein (food) for the cell
- releases energy from food.
 Which cells might have the most ribosomes?
4. Lysosomes
- contains chemicals (enzymes) to digest
wastes and ‘worn out’ parts of the cell.
- called ‘suicide sacs’
- break open and digest the cell when
it dies.
5. Vacuole
 Storage sacs
 Hold food, water, and wastes
 Larger in plant cells
6. Golgi Bodies

-packages and
secretes
substances to the
outer parts of the
cell
ASSIGNMENT:
WORKSHEET
“CELL STRUCTURE”.
COLORED PENCILS NEEDED TOMORROW!
PLANT CELLS
-have two different parts than animal
cells.
1.
Cell Wall
- found outside the
cell membrane.
- for support and
protection.
- non-living
2. Chloroplasts
- where photosynthesis
takes place (turns
sunlight into food).
- contains chlorophyll.
(green)
Two basic types of cells
1)
Prokaryotic cells
- oldest on Earth
- no membranes around internal
structures - (no nucleus)
-
very small
- simplest type of cell
ex. Bacteria
‘pond scum’
2) Eukaryotic cells
- organelles surrounded by a
membrane.
- has a nucleus
- most complex type of cell
- all plants and animals…
- much larger than prokaryotic
cells