Lindsay
Cell Theory

Cells are best described and studied by Robert Hooke.
When he studied the cells he used a early light
microscope. Hooke looked at the dried cork under this
microscope. After looking at hundreds of empty
chamber like pictures, he named them calls.

 Cytology is the study of the structure and function of
the cell.
 There are two other ways cells are revealed than the
one Hooke used. Another one is the transmission
electron microscopy, in this particular scope
electrons pass through a ultrathin section to strike a
photographic plate. The last one is the scanning
electron microscopy when electron bounce off
exposed surfaces to create a SEM.
Extracellular fluid

• Watery medium
• How a cell
survives
• Physiological
systems
• the cell membrane
separates the cell
membrane
contents.
Intracellular Fluid

• Also known as
cytosol
• Dissolves
nutrients, ions,
soluble and
insoluble
proteins, and
waste products.
Cell Membrane

 Also known as the plasma membrane.
 The cell membrane forms the otter boundary of the
cell.
 The layer is made up of the phospholipids, proteins,
glycolipids, and cholesterol.
The Cell and its
Environment

 The cell uses its environment in many ways, one is to
obtain water and also nutrients from the
environment.
 Also the boundary or barrier from the cell and its
environment its called the plasma membrane.
 A plasma membrane, is the outer boundary of the
cell.
Nonmembranous
Organelle

 Nonmembranous organelles are always in contact
with the cytosol.
 The cells Nonmembranous organelles are the
cytoskeleton, microvilli, centrioles, cilia, and flagella,
also the ribosomes.
Membranous Organelles

 This organelles are surrounded by a lipid membrane
that create space between the cytosol from the
extracellular fluid.
 They are bound by units somewhat like the cell
membrane.
Nonmembranous
Organelles

 Cytoskeleton- Strength movement of cellular
structures and materials.
 Microvilli- absorption of extracellular materials
 Centriole- Movement of chromosomes during cell
division.
 Cilia- Movement of materials over surface
 Ribosome- Protein synthesis.
Membranous Organelles

 Mitochondria-produces about 95 percent of the energy needed to keep a cell
alive
 Nucleus- control of metabolism, storage and processing genetic information
 Endoplasmic reticulum- secretory protein synthesis, lipid and carbohydrate
synthesis.
 Golgi Apparatus- Storage, alteration, and packing of secretory products and
lysosomes.
 Lysosomes- Intracellular removal of damaged organelles or of pathogens
 Peroxisomes- Neutralization of toxic compounds
Cell Power

 The sun is the main component in giving the cell fuel
to power all of their functions.
 Cells also get energy and power from the
mitochondria
 Mitochondria- are small organelles that have an
unusual double membrane.
 Having both of these energizers that gives the cell all
of its energy to fuel all of its functions.
Nucleus Game!

 http://www.sheppardsoftware.com/health/anatom
y/cell/cell_game.htm
Nucleus

 The nucleus is the control center for the cell, most
cells only have one nucleus.
 The nucleus directs processes that take in the cytosol.
 Also the nucleus takes in information about all of the
conditions and activities from the cell.
Cell Life & Cycle

 Cellular reproduction is done by the process of cell division. They are
six stages to the cell cycle.
 The first step is the G1 phase this happens when the cell starts to
divide
 Second step is S phase this is when the cells DNA replicates, also the
synthesis of histones.
 Next is G2 is protein synthesis
 From this point it turns into mitosis, which has 4 stages. Prophase,
metaphase, anaphase, and telophase.
 Cytokinesis- in a separate process from division of the genetic
materials in mitosis. During this time, the two daughter cells are
starting to be formed.
 At the end of the cell life cycle, daughter cells are formed. They are
each smaller to its parents but are two genetically identical daughter
cells.
Transmembrane
Potential

 The transmembrane potential is the characteristic of all living
cells because it results from the active and passive properties of
their cell membranes.
 Although the transmembrane potential is not visible through a
microscope, it is just as an important as any other structural
characteristic or organelle.
 Cell functions that involve the cell membrane involve the
transmembrane potential. Also because the transmembrane can
magnify a stimulus, it greatly increases the cells sensitivity to
its environment.
 The mechanisms that maintain the transmembrane potential is
the ions that are rushed into or out of the cell, but it does not
depend on the size or mature of the stimulus.

 Most cells in the body are firmly attached to other cells or
to extracellular protein fibers. The attached occur at the
cell junctions that are not involved in membrane flow.
There are four types of cell junctions Gap Junctions- are two cells are held together by an
interlocking of membrane proteins.
 Tight Junctions- there is a partial fusion of the lipid
portions of the two cell membranes.
 Intermediate Junctions- the opposing cell membranes,
while remaining distinct, are held together by a thick
layer of proteoglycan.
 Desmosomes- there a very thin proteoglycan layer
between the opposing cell membranes.