Chapter 7
Cell Discover & Theory
• What made the discovery of the cell
possible?
• Anton van Leeuwenhoek
– Dutch scientist (1675)
– Used a microscope to
view living creatures
from pond water.
• Mattias Schleiden
– German botanist (1838)
– Proposed that all plants
are made up of cells
•Theodore Schwann
–German zoologist (1839)
–Stated that all animals are
made up of cells
• Rudolph Virchow
– German physician
(1858)
– Determined that
cells come only
from other cells and
must be like the
original cell.
Cell Theory
• 1. All living things
are made up on one
or more cells.
• 2. Cells are the basic
units of structure and
function in
organisms.
• 3. All cells arise
from existing cells.
Cell Organelles
ORGANELLE
NAME
DESCRIPTION
PICTURE
Cell Wall
•
•
•
•
In plants & fungi ONLY
Composed of cellulose
Used for support and protection
Acts as a skeleton for plants
Cell (Plasma) Membrane
• Controls what moves in and out of the cell,
– Selectively permeable membrane – only allows selected
substances to move in & out
– Structure is a bilayer of phospholipid molecules with
proteins embedded in the layers. Proteins can act as
channels for molecules to move through membrane &
allow communication with environment.
Cytoplasm
• Clear, thick suspension
made up mostly of water,
like a nutrient broth
• Used to suspend the
organelles
Nucleus
•
•
•
•
Control center of the cell
Directs cell activities
Houses DNA & RNA
Membrane - nuclear envelop
nucleolus
Nuclear envelope
Vacuole
• Large Central Vacuole in plant cells ONLY
• Storage unit for food, water, and waste.
Vesicle
• Transports substances in cells, like a delivery truck
Lysosomes
• Contain enzymes that digest & recycle a cell’s
used parts; a garbage disposal
Cytoskeleton
• Microscopic fibers (microfilaments &
microtubules) used for support & structure, the
internal skeleton of the cell
Ribosomes
• Protein factories of the cell
• Makes proteins
Endoplasmic Reticulum (ER)
• A transportation system: internal membranes that
move protein & other substances through the cell,
– Rough ER: ribosomes attached
– Smooth ER: no ribosomes
Golgi Apparatus
• Packaging & distribution center of the
cell, like the Post Office
Chloroplast
• In plants ONLY
• Green structure that
stores energy from
the sun in sugar
molecules.
• Converts CO2 and
H2O into sugar and
O2
• Contains chlorophyll
for photosynthesis
Mitochondria
• Powerhouse of the cell
• Converts energy from organic compounds to ATP
Centrosome/Centrioles
• In animal cells ONLY
• Used in cell reproduction, builds microtubules
• Form a complex called the centrosome,