The Discovery of Cells
Cells - the basic unit of living organisms;
weren’t discovered until the invention of
the microscope (Anton van Leewenhoek).
The Discovery of Cells
The term “cells” was a term coined by
Robert Hooke as he studied the first cork
cells.
In fact, it was
Hooke who
coined the
term "cells":
the boxlike
cells of cork
reminded him
of the cells of
a monastery.
The Discovery of Cells
Types of Microscopes:
Light Microscope – uses a series of
lenses to magnify objects (1500x)
Electron Microscope – uses a beam of
electrons instead of light to magnify
structures
VIDEO Here
Cells Intro
The Discovery of Cells
Cell Theory (Schleiden and Schwann
contributed to these fundamental ideas)
All organisms are composed of one or
more cells.
The cell is the basic unit of structure and
organization of organisms.
All cells come from preexisting cells.
The Discovery of Cells
before
nucleus
true
nucleus
The Discovery of Cells
Two basic types of cells
Prokaryotes - cells that do NOT
have membrane bound
organelles.
Eukaryotes – cells that do contain
membrane bound organelles like
the nucleus, chloroplast, or
mitochondria
What do cells really look like?
Nerve cells
Red Blood Cells
Cardiac cells
Macrophage attacking a bacteria
HIV
Why are cells so
small ?????
http://www.cellsalive.com/howbig.htm
The Plasma Membrane
Survival of a cell depends the cell’s
ability to maintain the proper
conditions (homeostasis) within itself.
The plasma membrane is a flexible
boundary between the cell and its
environment.
The plasma membrane is selectively
permeable, which means that only
certain molecules can pass through.
http://www.stolaf.edu/people/giannini/flashanimat/lipids/membrane%20fluidity.swf
http://www.bio.davidson.edu/people/macampbell/111/memb-swf/membranes.swf
http://telstar.ote.cmu.edu/biology/downloads/membranes/index.html
Hydrophilic head
Hydrophobic tails
VIDEO Here
The Cell Membrane
http://telstar.ote.cmu.edu/biology/downloads/membranes/index.html
Cool animation
http://www.stolaf.edu/people/giannini/flashanimat/lipids/membrane%20fluidity.swf
http://www.cellsalive.com/cells/cell_model.htm
Parts of the Cell
Ribosomes – site of protein synthesis, made
up of rRNA
Golgi apparatus – folded membranes that
store and transports enzymes and hormones,
also produces the cell wall in plants
Cytoplasm – jelly-like material surrounding the
nucleus of the cell
Nucleus – The control center of the cell
Nucleolus – Site of ribosome synthesis
Nuclear Membrane – Surrounds the nucleus.
Cell Membrane – Membrane surrounding the
organelles and the cytoplasm of the cell.
Parts of the Cell
Mitochondria – The site of cellular respiration
or energy production. Membrane bound.
Rough Endoplasmic Reticulum – forms a link
between the nuclear membrane and the cell.
Ribosomes are attached to the surface.
Proteins are synthesized in the ribosomes and
enclosed in vessicles and sent to the Golgi.
Vacuole – Site of storage of glucose, water,
salts, and toxic substances. Larger in plants
cells than in animal cells.
Parts of the Cell
Cell Wall – Plant, fungal, and bacteria have a
cell wall that us used for support and
protection. It is composed of cellulose.
Chloroplast – Site of photosynthesis in the
plant and algal cell. They are generally lens
shaped and bound by a double membrane.
Smooth Endoplasmic Reticulum – It forms a
link between the nuclear membrane and the
cell. Site of many metabolic reactions and
synthesis of phospholipids and fatty acids.
Parts of the Cell
Lysosome – Contain enzymes needed for
digesting food, viruses, bacteria and old cells.
Centrioles – Not normally found in plant cells.
They are found in animal cells in pairs and are
necessary for cell division.