Guidelines for using Light
Carry the microscope with one hand holding
the arm and the other hand supporting the
Never slide the microscope across the lab
Clean lenses with lens paper only.
Always begin AND end with the lowest power
objective in place and the stage at its lowest
Use the coarse adjustment knob on low power
Use ONLY the fine adjustment knob on high
The Discovery of the Cell
• Looked at cells in cork and named them cells
• Observed pond water
• All plants and animals are made of cells
• Cells are produced from division of existing
Three Parts of the Cell Theory:
All living things are made up of cells.
The cell is the most basic unit of life.
New cells are produced from existing
Why are cells so small?
Small cells function more efficiently than
• All substances that enter and leave the cell
must cross the cell surface.
Cells need a high surface area to volume
ratio in order to exchange substances more
organism that lacks a
nucleus and other internal
Bacteria are common prokaryotes.
Pearson Education inc. 2010
Common Features of Cells
Cell membrane – thin flexible barrier that
encloses and separates the cell from it’s
Cytoplasm – the cell’s interior
Ribosomes – where proteins are made
Genetic Material – instructions for making
proteins, regulate cellular activities, and
Cells that contain a nucleus and internal
compartments called organelles.
Eukaryotic organisms can be one-celled
(unicellular) or contain many cells
supports and shapes cell
helps position and transport organelles
assists in cell division
aids in cell movement
Three types of cytoskeleton fibers:
Microfilaments – made up of protein and actin
Microtubules – made up of protein and tubulin
Intermediate fibers – thick ropes of protein
Controls most functions of
Most of the cell’s DNA
is contained in the
Surrounded by the
which separates the
nucleus from the
The nuclear envelope
contains small channels
called nuclear pores
which allow substances
to move in and out of the
free in the
cytoplasm or attached
to the rough
2 types of endoplasmic reticulum (ER):
• Rough ER – has attached ribosomes and
thus has a rough appearance.
– Helps transport proteins from ribosomes in
• Smooth ER – performs various functions
such as making lipids and breaking down
received in vesicles
from the ER.
• Some vesicles will
remain in the cytoplasm
lysosomes, which work
to remove waste in the
for storage of water, salts, proteins,
Harvest energy from organic
compounds to make ATP.
of a double layer of
• lipid bilayer
and supports the
Regulates what enters and
leaves the cell
• Selectively permeable
Unique features of plant cells
thick layer of protein and cellulose
surrounding the cell membrane.
use light energy to make carbohydrates from
carbon dioxide and water.
takes up much of the plant cell’s volume
Stores water and nutrients.